&TOBACCO Preventing Tobacco Use Among Young People A Report of the Surgeon General Produced by the Department of Health & Human Sewices Reprinted by the U.S. Department of Education Foreword Smoking kills an estimated 434,000 Americans each year, most of whom began smoking during their adolescence. The key to reducing this enormous death toll and the health consequences that accompany tobacco use, according to public health officials, is preventing young people from starting to use tobacco. Very few people begin to use tobacco as adults; almost all first use has occurred by the time people graduate from high school. By the age of 18, one in three persons is using tobacco. The earlier young people begin using tobacco, the more heavily they are likey to use it as adults, and the longer potential time they have to be users. Both the duration and the amount of tobacco use are related to eventual chronic health problems. This publication is adapted from Preventing Tobacco Use Among Young People: A Report of the Surgeon Gener- al released by the U.S. Department of Health and Human Services in 1994. The excerpts presented here provide important information for educators'about the vulnerable ages of 10 through 18 when most users start smoking, chewing, or dipping and become addicted to tobacco. It underscores the seriousness of tobacco use and the relationship of tobacco use to other adolescent problem behaviors. We appreciate the cooperation of the Office of the Surgeon General in making this report available for distribution by the Department of Education. Copies of the complete document are available for sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C., 20402, S/N 017-001-00491-0. CONTENTS Chapter 1: Introduction ............................... 5 Chapter 2: Health Consequences of Tobacco Use by Young People ...... 11 Chapter 3: -Epidemiology of Tobacco Use Among Young People in the United States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Chapter 4: Psychosocial Risk Factors for Initiating Tobacco Use . . . . . . . . 89 Chapter 5: Efforts to Prevent Tobacco Use Among Young People ....... 115 References .......... .' ............................. 183 pwzlenting Tobacco Use Among Young People Chapter 1 Introduction Previous Surgeon General's reports on tobacco use and health have largely focused on the epidemiologic, clinical, biologic, and pharmacologic aspects of adult use of tobacco products. This report on Preventikg Tobacco use A?nong Young People provides a more detailed look at adolescence, the time of life when most tobacco users begin, develop, and establish their behavior. Because regular use soon results in addiction to nicotine, this behavior may persist through adulthood, significantly increasing, through the extended years of use, the risk of long-term, severe health consequences. Despite three decades of explicit health warnings, large numbers of young people continue to take up tobacco; currently, over three million adolescents smoke cigarettes, and over one million adolescent males cur- rently use smokeless tobacco. Clearly, effective interven- tions are needed to prevent more young people from trying tobacco. TO achieve significant long-term reduc- tions in tobacco use and tobacco-related deaths in the United States, we must examine the nature and scope of adolescent tobacco use, consider the social, psychologi- cal, and marketing factors that influence young people in their decision to use tobacco products, and evaluate cur- rent efforts to prevent young people from becoming users. This report addresses the crucial problems of adolescent tobacco use. Development of the Report This report of the Surgeon General was prepared by the Office on Smoking and Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Public Health Service, U.S. Department of Health and Human Services, as part of the department's responsibility, under Public Law 91-222 and Public Law 99-252, to report current information on the health effects of cigarette smoking and smokeless tobacco use to the United States Congress. This report is the first to focus on the problem of tobacco use among young people. Given the continuing onset of use in adolescence and the growing evidence of health consequences associated with early use, the report was seen as both needed and timely. The current report has been produced through the efforts of experts in the medical, pharmacologic, epidemiologic, developmental, economic, behavioral, legal, and public health aspects of smoking and smoke- less tobacco use among young people. Initial manu- scripts for the report were prepared by 28 scientists who were selected for their expertise in specific content areas. This material was consolidated into chapters, each of which underwent peer review. The entire document was reviewed by a number of experts in the field, as well as by institutes and agencies within the U.S. Public Health Service. The final draft of the report was reviewed by the Assistant Secretary for Health and by the Secretary, Department of Health and Human Services. Several concerns guided the development of this report. The first, which is addressed in Chapter 2, is whether tobacco use is associated with health conse quences during the period of adolescence (broadly de- fined as ages 10 through 18, although research cited in this report varies somewhat in the ages considered ado- lescent). The long-term health consequences-that is, those that emerge in adulthood-have been the subject of extensive review and are widely acknowledged in the scientific and public literature. The chapter thus focuses on the serious health consequences, as well as the in- creased risk factors for subsequent health consequences, that are evident early in life among young smokers and smokeless tobacco users. Chapter 3 examines the epidemiologic patterns of tobacco use among the young. National data on trends in adolescent use are analyzed to determine the extent of the current problem, as well as to note changes in patterns of initiation and use. The factors that influence adolescents in their decision to use tobacco are examined in Chapter 4, which considers psychosocial risk factors, and Chapter 5, which examines the influence of tobacco advertising and promotion. The final concern, the focus of Chapter 6, was to assess what has been don-from the individual level to the legislative level- to prevent tobacco use among young people. Major Conclusions 1. Nearly all first use of tobacco occurs before high school graduation; this finding suggests that if ado- lescents can be kept tobacco-free, most will never start using tobacco. 2. Most adolescent smokers are addicted to nicotine and report that they want to quit but are unable to do so; they experience relapse rates and withdrawal symptoms similar to those reported by adults. 3. Tobacco is often the first drug used by those young people who use alcohol, marijuana, and other drugs. Introduction 5 Surgeon General's Rep01 4. Adolescents with lower levels of school achieve- ment, with fewer skills to resist pervasive influences to use tobacco, with friends who use tobacco, and with lower self-images are more likely than their peers to use tobacco. 5. Cigarette advertising appears to increase young people's risk of smoking by affecting their perceptions of the pervasiveness, image, and fur lion of smoking. 6. Communitywide efforts that include tobacco tax i creases, enforcement of minors' access laws, you1 oriented mass media campaigns, and school-has tobacco-use prevention programs are successful reducing adolescent use of tobacco. Introduction The health effects of cigarette smoking have been the subject of intensive investigation since the !95Ck. Ciga- rette smoking is still considered the chief preventable cause of premature disease and death in the United States. As was documented extensively in previous Sur- geon General's reports, cigarette smoking has been caus- ally linked to lung cancer and other fatal malignancies, atherosclerosis and coronary heart disease, chronic ob- structive pulmonary disease, and other conditions that constitute a wide array of serious health consequences (USDHHS 1989). More recent studies have concluded that passive (or involuntary) smoking can cause disease, including lung cancer, in healthy nonsmokers. In 1986, an advisory committee appointed by the Surgeon Gen- eral released a special report on the health consequences of smokeless tobacco, concluding that smokeless tobacco use can cause cancer and can lead to nicotine addiction WSDHHS 1986). In the 1988 report, nicotine was desig- nated a highly addictive substance, comparable in its physiological and psychological properties to other ad- dictive substances of abuse (USDHHS 1988). Considerable evidence indicates that the health problems associated with smoking are a function of the duration (years) and the intensity (amount) of use. The younger one begins to smoke, the more likely one is to be a current smoker as an adult. Earlier onset of cigarette smoking and smokeless tobacco use provides more life years to use tobacco and thereby increases the potential duration of use and the risk of a range of more serious health consequences. Earlier onset is also associated with heavier use; those who begin to use tobacco as younger adolescents are among the heaviest users in adolescence and adulthood. Heavier users are more likely to experience tobacco-related health problems and are the least likely to quit smoking cigarettes or using smokeless tobacco. Preventing tobacco use among you"g people is therefore likely to affect both duration and intensity of total use of tobacco, potentially reducing long-term health consequences significantly. Health Consequences of Tobacco Use Among Young People Active smoking by young people is associated with significant health problems during childhood and adolescence and with increased risk factors for health problems in adulthood. Cigarette smoking during adolescence appears to reduce the rate of lung growth and the level of maximum lung function that can be achieved. Young smokers are likely to be less physically fit than young nonsmokers; fitness levels are inversely related to the duration and the intensity of smoking. Adolescent smokers report that they are significantly more likely than their nonsmoking peers to experience shortness of breath, coughing spells, phlegm production, wheezing, and overall dimin- ished physical health, Cigarette smoking during child: hood and adolescence poses a clear risk for respiratory symptoms and problems during adolescence; these health problems are risk factors for other chronic con ditions in adulthood, including chronic obstructive pulmonary disease. Cardiovascular disease is the leading cause 01 death among adults in the United States. Atheroscle rosis, however, may begin in childhood and becorn clinically significant by young adulthood. Cigarett~ smoking has been shown to be a primary risk facto: for coronary heart disease, arteriosclerotic periphera vascular disease, and stroke. Smoking by childrer and adolescents is associated with an increased risk o early atherosclerotic lesions and increased risk factor for cardiovascular diseases. These risk factors i&,rd, increased levels of low-density lipopr&$n &&&d increased very-low-density lipoprotein cholesterol increased triglycerides, and reduced levels Q 6 Introduction pwzlenting Tobacco Use Among Young People h@density lipoprotein cholesterol. If sustained into adulthood, these patterns significantly increase the risk for early development of cardiovascular disease. Smokeless tobacco use is associated with health consequences that range from halitosis to severe health problems such as various forms of oral cancer. Use of Smokeless tobacco by young people is associated with early indicators of adult health consequences, including periodontal degeneration, soft tissue lesions, and general systemic alterations. Previous reports have documented that smokeless tobacco use is as addictive for young people as it is for adults. Another concern is that smoke- less tobacco users are more likely than nonusers to be- come cigarette smokers. Among addictive behaviors such as the use of alco- hol and other drugs, cigarette smoking is most likely to become established during adolescence. Young people who begin to smoke at an earlier age are more likely than later starters to develop long-term nicotine addiction. Most young people who smoke regularly are already addicted to nicotine, and they experience this addiction in a manner and severity similar.to what adult smokers experience. Most adolescent smokers report that they would like to quit smoking and that they have made numerous, usually unsuccessful attempts to quit. Many adolescents say that they intend to quit in the future and yet prove unable to do so. Those who try to quit smoking report withdrawal symptoms similar to those reported by adults. Adolescents are difficult to recruit for formal cessation programs, and when enrolled, are difficult to retain in the programs. Success rates in adolescent cessa- tion programs tend to be quite low, both `in absolute terms and relative to control conditions. Tobacco use is associated with a range of problem behaviors during adolescence. Smokeless tobacco or cigarettes are generally the first drug used by young people in a sequence that can include tobacco, alcohol, marijuana, and hard drugs. This pattern does not imply that tobacco use causes other drug use, but rather that other drug use rarely occurs before the use of tobacco. Still, there are a number of biological, behavioral, and social mechanisms by which the use of one drug may facilitate the use of other drugs, and adolescent tobacco users are substantially more likely to use alcohol and illegal drugs than are nonusers. Cigarette smokers are also more likely to get into fights, carry weapons, attempt suicide, and engage in high-risk sexual behaviors. These problem behaviors can be considered a syndrome, since involvement in one behavior increases the risk for in- volvement in others. Delaying or preventing the use of tobacco may have implications for delaying or prevent- ing these other behaviors as well. The Epidemiology of Tobacco Use Among Young People Overall, about one-third of high-school-aged ado- lescents in the United States smoke or use smokeless tobacco. Smoking prevalence among U.S. adolescents declined sharply in the 197Os, but this decline slowed significantly in the 198Os, particularly among white males. Although female adolescents during the 1980s were more likely than male adolescents to smoke, female and male adolescents are now equally likely to smoke. Male ado- lescents are substantially more likely than females to use smokeless tobacco products; about 20 percent of high school males report current use, whereas only about 1 percent of females do. White adolescents are more likely to smoke and to use smokeless tobacco than are black and Hispanic adolescents. Sociodemographic, environmental, behavioral, and personal factors can encourage the onset of tobacco use among adolescents. Young people from families with lower socioeconomic status, including those adolescents living in singleparent homes, are at increased risk of initiating smoking. Among environmental factors, peer influence seems to be particularly potent in the early stages of tobacco use; the first tries of cigarettes and smokeless tobacco occur most often with peers, and the peer group may subsequently provide expectations, re- inforcement, and cues for experimentation. Parental tobacco use does not appear to be as compelling a risk factor as peer use; on the other hand, parents may exert a positive influence by disapproving of smoking, being involved in children's free time, discussing health mat- teGwith children, and encouraging children's academic achievement and school involvement. How adolescents perceive their social environment may be a stronger influence on behavior than the actual environment. For example, adolescents consistently over- estimate the number of young people and adults who smoke. Those with the highest overestimates are more likely to become smokers than are those with more accu- rate perceptions. Similarly, those who perceive that ciga- rettes are easily accessible and generally available are more likely to begin smoking than are those who per- ceive more difficulty in obtaining cigarettes. behavioral factors figure heavily during adoles- cence, a period of multiple transitions to physical matu- ration, to a coherent sense of self, and to emotional independence. Adolescents are thus particularly vulner- able to a range of hazardous behaviors and activities, including tobacco use, that may seem to assist in these transitions. Young people who report that smoking serves positive functions or is potentially useful are at increased risk for smoking. These functions are associated with Introduction 7 Surgeott General's Report bonding with peers, being independent and mature, and having a positive social image. Since reports from adolescents who begin to smoke indicate that they have lower self-esteem and lower self-images than their non- smoking peers, smoking can become a self-enhancement mechanism. Similarly, not having the confidence to be able to resist peer offers of tobacco seems to be an impor- tant risk factor for initiation. Intentions to use tobacco and actual experimentation also strongly predict subse- quent regular use. The positive functions that many young people attribute to smoking are the same functions advanced in most cigarette advertising. Young people are a strategi- cally important market for the tobacco industry. Since most smokers try their first cigarette before age 18, young people are the chief source of new consumers for the tobacco industry, which each year must replace the many `consumers who quit smoking and the many who die from smoking-related diseases. Despite restrictions on tobacco marketing, children and adolescents continue to be exposed to cigarette advertising and promotional ac- tivities, and young people report considerable familiar- ity with many cigarette advertisements. In the past, this exposure was accomplished by radio and television pro- grams sponsored by the cigarette industry. Barred since 1971 from using broadcast media, the tobacco industry increasingly relies on promotional activities, including sponsorship of sports events and public entertainment, outdoor billboards, point-of-purchase displays, and the distribution of specialty items that appeal to the young. Cigarette advertisements in the print media persist; these messages have become increasingly less informational, replacing words with images to portray the attractive ness and function of smoking. Cigarette advertising fre- quently uses human models or human-like cartoon characters to display images of youthful activities, inde- pendence, healthfulness, and adventure-seeking. In pre- senting attractive images of smokers, cigarette advertisements appear to stimulate some adolescents who have relatively low self-images to adopt smoking as a way to improve their own self-image. Cigarette adver- tising also appears to affect adolescents' perceptions of the pervasiveness of smoking, images of smokers, and the function of smoking. Since these perceptions are psychosocial risk factors for the initiation of smoking, cigarette advertising appears to increase young people's risk of smoking. Efforts to Prevent the Onset of Tobacco Use Most of the U.S. public strongly favors policies that might prevent tobacco use among young people. These policies include mandated tobacco education in schools, a complete ban on smoking by anyone on school grounds, further restrictions on tobacco advertising and promo ti0~1 activities, stronger prohibitions on the sale of to bacco products to minors, and increases in earmarked taxes on tobacco products. Interventions to prevent ini- tiation among young people--even actions that involve restrictions on adult smoking or increased taxes-have received strong support among smoking and nonsmok- ing adults. Numerous research studies over the past 15 years suggest that organized interventions can help prevent the onset of smoking and smokeless tobacco use. School- based smoking-prevention programs, based on a model of identifying social influences on smoking and provid- ing skills to resist those influences, have demonstrated consistent and significant reductions in adolescent smok- ing prevalence; these program effects have lasted one to three years. Programs to prevent smokeless tobacco use have used a similar model to achieve modest reductions in initiation of use. The effectiveness of these school- based programs appears to be enhanced and sustained, at least until high school graduation, by adding coordi- nated communitywide programs that involve parents, youth-oriented mass media and counteradvertising, com- munity organizations, or other elements of adolescents' social environments. A crucial element of prevention is access: adoles- cents should not be able to purchase tobacco products in their communities. Active enforcement of age-at-sale policies by public officials and community members ap- pears necessary to prevent minors' access to tobacco. Communities that have adopted tighter restrictions have achieved reductions in purchases by minors. At the state and national levels, price increases have significantly reduced cigarette smoking; the young have been at least as responsive as adults to these price changes. Maintain- ing higher real prices of cigarettes provides a barrier to adolescent tobacco use but depends on further tax in- creases to offset the effects of inflation. The results of this review thus suggest that a coordinated, multicomponent campaign involving policy changes, taxation, mass me- dia, and behavioral education can effectively reduce the onset of tobacco use among adolescents, s-ary Smoking and smokeless tobacco use are almost always initiated and established in adolescence. besides its long-term effects on adults, tobacco use produces specific health problems for adolescents. Since nicotine addiction also occurs during adolescence, adolescent to- bacco users are likely to become adult tobacco users. Smoking and smokeless tobacco use are associated with other problem behaviors and occur early in the sequence of these behaviors. The outcomes of adolescent smoking 8 Introduction pr~lenting Tobacco Use Among Young People and smokeless tobacco use continue to be of great public relevant, and tobacco use may begin. This process most health importance, since one out of three U.S. adoles- affects adolescents who, compared with their peers, have cents uses tobacco by age 18. The social environment of lower self-esteem and self-images, are less involved with adolescents, including the functions, meanings, and im- school and academic achievement, have fewer skills to ages of smoking that are conveyed through cigarette resist the offers of peers, and come from homes with advertising, sets the stage for adolescents to begin using lower socioeconomic status. Tobacco-use prevention tobacco. As tobacco products are available and as peers programs that target the larger social environment of begin to try them, these factors become personalized and adolescents are both efficacious and warranted. References us DEPARTMENT OF HEALTH AND HLJMAN SERVICES. US DEPARTMENT OF HEALTH .AND HUMAN SERVICES. The health consequences of using smokeless tobacco. A report of the advisory committee to the Surgeon General. US Department of Health and Human Services, Public Health Services, National Institutes of Health. NIH Publication No. 86-2874, 1986. Reducing the health consequences of smoking: 25 years of progress. A report of the Surgeon General. US Department of Health and Human Services, Public Health Service, Centers for Disease Control, Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health. DHHS Publication US DEPARTMENT OF HEALTH AND HUMAN SERVICES. The health consequences of smoking: nicotine addiction. A report of the Surgeon General, 1988. US Department of Health and Human Services, Public Health Service, Centers for Disease Control, Center for Health Promotion and Education, Office on Smoking and Health. DHHS Publication No. (CDC) M-8406, 1988. No. (CDC) 89-8411, 1989. prezIenting Tobacco Use Among Young People Chapter 2: The Health Consequences of Tobacco Use by Young People htroduction The health consequences of tobacco use among adults have been reviewed extensively in previous Surgeon General's reports (Public Health Service [PHSI 1964; U.S. Department of Health and Human Services [USDHHS] 1986b, 1989). Among young people, the short-term health consequences of smoking include respiratory and nonrespiratory effects, addiction to a toxic substance (nicotine), and the associated risk of other drug use. Long-term health consequences of adolescent smoking may be seen in the association between early onset of tobacco use and future (adult) smoking, with concomitant health consequences. Passive (also called "involuntary") smoking during adolescence is also asso- ciated with harmful respiratory and nonrespiratory effects. Lastly, the use of smokeless tobacco poses seri- ous health consequences to young people. Health Consequences of Smoking Among Young People Introduction The health effects of cigarette smoking have been the subject of intensive investigation since the 19%. Extensive evidence, documented in numerous reports of the Surgeon General, has causally linked cigarette smoking to a wide array of health outcomes that extend from annoying symptoms to fatal malignancies (USDHHS 1989). Until recently, this research was largely directed at the effects of smoking on adults. As is discussed in Chapter 3 (see "Age or Grade When Smok- ing Begins"), the onset and development of cigarette use occur primarily during adolescence (USDHHS 1989); the health consequences of smoking among young people thus have great public health significance. In recent years, investigations of the health effects in school- age youth have reported sufficient data to support conclusions about adverse effects of smoking during childhood and adolescence. Most of the evidence reviewed here is gathered from epidemiologic studies of young people ranging from 10 through 20 years old. Selected studies that relate to older age groups, yet are relevant to young people, are also included. Emphasis is placed on the res- piratory effects of smoking, for which the evidence is abundant. Data on smoking and cardiovascular risk factors and atherogenesis are also addressed, as are the adult health implications of starting to smoke during childhood. overview of the Toxicology of Tobacco Smoke Cigarette smoke is a complex mixture of organic and inorganic compounds generated by the combustion of tobacco and additives. Current knowledge about the physicochemical nature of tobacco smoke is well de- scribed in earlier Surgeon General's reports (PHS 1964; USDHHS 1981, 1989). Thousands of individual com- pounds have been isolated in cigarette smoke, including pharmacologically active agents (e.g., nicotine), toxic agents (e.g., carbon monoxide, hydrogen cyanide, and acrolein), and mutagens and carcinogens (e.g., polycy- clic aroma tic hydrocarbons). Cigarette smoke is further classified as mainstream smoke (MS), the smoke drawn through the mouthpiece of the cigarette, and sidestream smoke (SS), the smoke given off by smoldering tobacco between puffs and the smoke diffusing through the cigarette paper and escap- ing from the burning cone during puffing. Because of the differing combustion conditions under which MS and SS are generated, their chemical compositions differ; in par- ticular, undiluted SS tends to have higher concentrations of many toxic and tumorigenic agents (USDHHS 1986a, 1989). The quantitative yields of tar (the material depos- ited in a filter as MS is being drawn), nicotine, and carbon monoxide from cigarettes can be assessed by using a smoking machine standardized to a particular pattern of puffing (USDHHS 1989). Passive smoking refers to nonsmokers' inhalation of tobacco smoke. The term "environmental tobacco smoke" (E'TS) is now widely used to refer to the mixture of predominantIy SS and exhaled MS that is inhaled by the passive smoker. Passive smoking was the subject of the 1986 Surgeon General's report (USDHHS 1986a); that report reviews in detail the components of ETS, as did a contemporaneously prepared report of the National Re- search Council (1986). In 1991, the National Institute for Occupational Safety and Health recommended that ETS be regarded as a potential occupational carcinogen and Health Consequences 21 Surgeon General's Reports that exposures to ETS be reduced to the lowest feasible concentration (USDHHS 1991b). A recent monograph by Guerin, Jenkins, and Ton&ins (1992) updates and extends these earlier revie.ws. The U.S. Environmental Protection Agency (USEPA) also recently reviewed the evidence on invohmtary smoking and respiratory health (USEPA 1992). These and other health consequences of passive smoking are discussed later in this chapter. Many of the components of SS and MS have been identified in ETS. On the other hand, ETS is an inherently dynamic mixture that changes in physical and chemical characteristics as it ages and reacts with other pollutants in indoor air and with surfaces (USDHHS 1986a; Guerin, Jenkins, Tomkins 1992). The 1986 Surgeon General's report concluded, however, that ETS was sufficiently close to MS and SS to permit generalization of the evi- dence on the health consequences of active smoking to passive smoking (USDHIHS 1986a). The human body is most susceptible to these health consequences along cigarette smoke's path of ingress through the respiratory tract. The respiratory tract in- cludes the upper airway (nose, oropharynx, and larynx) and the lung (airways and the parenchyma). The air- ways are lined by an epithelium that varies in form and function at different levels of the respiratory tract. The parenchyma includes the alveoli pulmonis (the delicate gas-exchanging surface of the lung) and the interstitiurn (the location of the blood and lymphatic vessels and of the lung's supporting connective tissue). The effects of active' cigarette smoking on these structures of the lung and on many ,physiological func- tions of the lung have been extensively studied (USDHHS 1984, 1990; Bates 1989). Changes in lung physiology attributable to smoking include the weakening of an individual's defenses against infectious organisms and inhaled particles and gases, changes in the numbers and types of cells present within the lung, and the activation of potentially damaging proteolytic enzymes and the inactivation of the proteins that inhibit them. Many of theseeffects of smoking have been demonstrated in young adult smokers who have served as volunteer research subjects WSDHHS 1984). The effects of smoking on lung structure and fun& tion have been demonstrated repeatedly in young adult smokers (USDHHS 1984; Bates 1989). Studies using spirometry, tests of small airway function, and lung vol- ume measurements have shown a higher frequency of abnormalities in smokers than nonsmokers (USDHHS 1984; Bates 1989). Effects of smoking on lung structure, particularly the small airways, have been found in smok- ers in their mid-twenties. Niewoehner, Kleinerman, and `Unless otherwise indicated, "smoking" will hence refer to active smoking. Rice (1974) examined peripheral airways of 20 nonsmok- ers and 19 smokers who had died from nonrespiratory causes at an average age of 25. A characteristic lesion, termed "respiratory bronchiolitis," was found in all 19 of the smokers but in only 5 of the nonsmokers. The affected small airways of the smokers demonstrated an inflammatory process consisting of aggregates of pigment-containing macrophages with edema, fibrosis, and epithelial hyperplasia in adjacent bronchioles and alveoli. These observations on the effects of smoking in young people are consistent with current concepts of pathogenesis and natural history in adult smokers WSDHHS 1984,WO). Severe chronic airflow obstruc- tion, sufficient to result in a clinical diagnosis of chronic obstructive pulmonary disease (COPD), follows sustained smoking and lung injury with progressive loss of respi- ratory function through adulthood. In smokers whc develop COPD, decline of lung function at a rate weE beyond that associated with aging alone eventually lead: to impairment. Changes in lung function can be demon strated in young adult smokers; these losses are consis tent with the histopathologic evidence that the smal airways of young smokers are damaged (USDHHS 19841 Epidemiologic Evidence of Respiratory Effects Respiratory Symptoms The cardinal symptoms of respiratory tract iniur] and disease are cough, sputum production, wheezing and dyspnea (or shortness of breath). In epidemiologi studies of respiratory diseases, symptoms are usual& discovered through responses to a standardized ques tionnaire @met 1978). In adults, the occurrence of cougl and phlegm is causally associated with cigarette smok ing; the frequency of the symptoms rises with the num ber of cigarettes smoked per day (USDHHS 1984). I: some studies, wheezing is also more frequent in adti smokers than in adults who have never smoke1 (Schenker, Samet, Speizer 1982). The frequency E dyspnea rises as the extent of smoking-related impati ment of lung function increases &met 1978). Questionnaire-based epidemiologic studies of chi dren and adolescents document that smoking is also cause of respiratory symptoms in preteen and teenag regular smokers (those who smoke at least weekly Studies conducted from the 1960s through the 198( involving thousands of children provide consistent ev dence that smoking is associated with the occurrence 4 cough and phlegm (Table 1; see Table 31 in Chapter 3 fc additional data). In several studies, smoking also in creased the frequency of wheezing and dyspnea. Ther associations have been found in studies conducted in ti 22 Health Consequences preventing Tobacco Use Among Young People United States, the United Kingdom, New Zealand, and Scandinavia and at levels of smoking as low as one cigarette per week. In one of the first studies on smoking and respira- tory symptoms in children, Holland and Elliott (1968) administered a questionnaire concerning reSpiratOI'y symptoms and cigarette smoking to all children in schools in four areas of southeast England. Smoking education was then p!ovided to half of the schools, and the questionnaire was readministered one year later. Although the intervention had no effect on the preva- lence of smoking, the study documented that smoking in childhood was associated with cough and phlegm and that these symptoms were reduced in those who had stopped smoking. Many later studies continued to show that smok- ing increased the frequency of respiratory symptoms in children and adolescents. In the United States, reseaich with high school students (Addington et al. 1970; Seely, Zuskin, Bouhuys 1971; Rush 1974) and college students (Peters and Ferris 1967) provided early evidence of ad- verse effects of smoking on young smokers. Large stud- ies of schoolchildren (including preteens) in the United Kingdom showed that symptom rates were increased by smoking. Bewley, Halil, and Snaith (1973) reported that the frequency of cough was increased in boys and girls no older than 11.5 years who reported smoking at least one cigarette per week. Other studies in the United Kingdom and the United States found further evidence of the effects of smoking on symptom frequency in chil- dren of similar ages (Bewley and Bland 1976; Charlton 1984; see Table 31 in Chapter 3). The health effects of smoking among adolescents may be confounded by a history of passive smoking if the parents of an adolescent smoker also smoke. How- ever, in a study of 5,835 secondary schoolchildren in Derbyshire (United Kingdom), students who smoked at least one cigarette per week persisted in having an in- creased risk for cough and dyspnea even after parental smoking was taken into account (Bland et al. 1978). Control for other potential confounding or mediat- ing factors varies among the investigations. Residence location, a surrogate for exposure to ambient air pollu- tion, was considered in several of the studies (Bewley, Hahi, Snaith 1973; Bewley and Bland 19761, and a study of 20-year-olds (Colley, Douglas, Reid 1973) controlled for socioeconomic status. Lung Function Numerous cross-sectional studies of adults have shown that cigarette smokers have a lower level of lung function, as assessed by tests of lung mechanics and gas exchange, than persons who have never smoked (USDHHS 1984; Bates 1989). Longitudinal studies show that smoking speeds the age-related decline of lung func- tion. The most abundant evidence describes changes in lung function as assessed by spirometry, or the measure of the volume of air entering and leaving the lungs. One measure of scientific and clinical interest obtained through spirometry is the forced expiratory volume in one se- cond (FEV,), the volume of air blown out during the first second of the forced vital capacity maneuver. FEV, increases with lung growth and development dur- ing childhood, and rises even more steeply with the growth spurt of adolescence (Tager et al. 1988; Sherrill et al. 1992). In persons who have never smoked, FEV, begins to decline from a maximum at some time during the third or fourth decades of life (Beck, Doyle, Schachter 1982; Tager et al. 1988). In smokers, the age- related decline commences at a younger age and pro- ceeds at a steeper average rate (Beck, Doyle, Schachter 1982; USDHHS 1984; Tager et al. 1988). When people stop smoking, their average decline gradually returns to the rate observed in those who never smoked (USDHHS 1990). Cross-sectional and longitudinal data show that smoking also adversely affects lung function in children and adolescents (Table 2). The evidence comes princi- pally from spiromev studies of high school students, although one of the first studies to show reduced lung function in young people involved college seniors (Pe- ters and Ferris 1967). In these studies, impaired lung function has been primarily indicated through reduced flow rates after 50 percent or more of the vital capacity has been exhaled. This effort-independent, latter portion of the flow-volume loop is sensitive to abnormalities of the lung's small airways and the lung parenchyma (Bates 1989). Several studies have also found that smokers have a reduced peak expiratory flow rate (PEER) (Table 2). This effortdependent portion of the flow-volume loop is more sensitive to abnormal function of the lung's larger airways than of its small airways (Bates 1989). Among the first researchers to study smoking among younger people were Peters and Ferris (1%7L who obtained spirometric and peak-flow data from 124 Harvard College seniors. Smokers had lower (although not signifi- cantly) FEV, than persons who had never smoked. Spiro- metric flow rates and PEFR were significantly lower in the smokers. In an early study involving high school students, Seely, Zuskin, and Bouhuys (197l) found evidence of abnor- mal function of the small airways in both boys and girls who smoked. subsequent crossBhonal studies of teenageIs have tended to confirm that smokers have reduced lung function, as assessed by spir&netry or PEFR measurement. More recent, longitudinal data show that smoking reduces the rate of lung growth, as would be anticipated Health Consequences 13 Surgeon General's Report Table 1. Published studies of the effects of smoking on respiratory symptoms among young people, various countries, 1965-1983 Reference* Location/year Study population Peters and Ferris 1967 Massachusetts, 1965 124 Harvard College seniors Addington et al. 1970 Oklahoma" 557 high school students, (grades 9-12) aged 13-19 years Bewley, Halil, Snaith 1973 England, 1971 8,682 schoolchildren aged 10 and 11 years Rush 1974 New York, 1968 12,595 high school students aged 13-18 years *Listed chronologically by publication date. _Year not provided. 14 Health Consequences preventing Tobacco Use Among Young People Symptoms Prevalence (o/o) by smoking status Never smoker Smoker+ Phlegm b 3 months/yr Breathlessness Wheezing (apart from colds) Colds go to chest 2.4 26.5' 2.4 20.5t 7.3 31.3* 4.9 31.3r Never smoker Smoker' Daily cough L 3 months 4 10 Daily phlegm 2 3 months 3 9 Dyspnea when hurrying 16 30 Chest cold for 1 week 22 30 Wheezing or asthma 12 13 Morning cough Boys Girls Never smoker Smoker' 5.4 18.2 5.9 19.8 Cough 3 months Boys Girls 3.8 15.4 3.5 12.1 Nonsmoker Ex-smoker Smoker Number of cigarettes smoked per day Cough 2 3 months/yrT I l-9 10-14 L 15 BOYS 2.9 4.5 9.2 16.2 29.0 Ci*lc2 AA 6.0 12.0 23.1 35.9 `At Least one cigarette daily for the past year. `p < 0.01. Smoking at least one cigarette weekly. Percentages combine data reported separately in authors' Table 4 for urban and rural children. `For white children only. Health Consequences 25 Surgeon Generals Repor Table 1. Continued Reference Location/year Study population Stanhope and Prior 1975 _ _. -I .y- 1`;..., 1 ;"`-; BewIey and Bland 1976 : . / . ._ ~. : .;_' ._ New Zealand, 1972 Maori and European high school students aged 13-15 years Bland et al. 1978 England, 1974 5,835 schoolchildren; first-year level in secondary school Charlton 19&I `. : .' .' _- -,* Adams et al. 1984 England, 1975-1979 405 secondary schoolchildren Oechsli, Seltzer, van den Berg 1987 California, 1977-l 979 1,445 children in a cohort study "Smoking at least one c@ar&e weekly, Percentages combine data reported separately in authors' Table V for urban and rural children. "RR = Relative risk for &U-en smoking z one cigarette weekly versus children who had never smoked, adjusted for parental smoking. @Smoking at least one cigarette weekly. 16 Health Consequences prczlenting Tobacco Use Among Young People Symptoms Prevalence (o/o) by smoking status &werul finding: Cough grade, phlegm grade, and loose cough sign significantly associated with smoking. Morning cough Boys Girls Cough day or night Boys Girls BreathIessness Boys Girls Never smoker Smoker# RR% 3.1 19.2 5.9 1.8 13.5 6.8 20.4 46.5 2.4 18.5 47.3 2.6 11.8 34.9 2.9 16.5 39.2 2.3 Cough all day 1 2 8 Phlegm all day 1 1 7 Wheezing 5 13 22 General findings: Increased risk of cough, dyspnea, and phlegm. Genernl findings: Starting smoking associated with bronchitis and pneumonia. "RR = Relative risk for children smoking at least one cigarette weekly versus children who had never smoked. UNon.smoker = Never smoking and smoking not more than one cigar&e daily for I one year. "Exsmoker = Smoking one month or more before date of the interview. "Smoker = Smoking t lg of tobaox daily; one cigarette was estimated to contain lg of tobacco. smoking daily, cigamites < I Omg of tar. "Smoking daiIy, cigarettes lo-18mg of tar. Health Consequences 17 Surgeon General's Repor Table 2. Published studies of the effects of smoking on lung function among young people, various countries, 19651981 Reference* Location/year Study population Findings+ Comment Peters and Ferris 1967 Massachusetts, 1965 124 Harvard College seniors Significant reduction in spirometric flow Age distribution not given, non- rates when compar- ing NS with persons significant reduc- smoking a pack a day tion for FEV,. for four years during college; dose response with amount smoked. Seely, Zuskin, Bouhuys 1971 Connecticut' 195 male and 170 female high school students aged 15-19 years From MEFV curves, V, and V, signifi- cantly reduced in boys smoking > 15 c&s/day and girls smoking z= 10 cigs/day, when compared with NS. Age distribution not given, non- significant reduc- tion for FEV,. Comstock and Rust 1973 Nationwide, 1970-1971 3,409 U.S. Navy recruits, median age = 19 years PEFR lower in smokers (99.5% predicted) than in nonsmokers (100.7% predicted). No definition of smoker, nonsmoker; tests of statistical significance not provided. *Listed chronologically by publication date. `NS = never smoker; FEV, = forced expiratory volume in one second; VC = vital capacity; MEFV = maximal expiratory flov volume; V, = flow rate at 50% of vital capacity; V, = flow rate after exhalation of 75% of vital capacity; FVC = forced vital capacity; PEFR = peak expiratory flow rate; FEFsz = forced expiratory flow from 25% to 75% of FVC. *ear not provided. 18 Health Consequences Preventing Tobacco Use Among Young People Table 2. Continued Reference Study Loca tionlyear population Findings' Comment - Backhouse 1975 United Kingdom* 195 boys at a PEFR on arrival None detention center, dropped significantly mean age = 18 years with daily smoking amount; significant improvement during &week stay while unable to smoke Woolcock et al. Australia, 1979 1971-1980 10,898 school No overall effect of See text for review children, mean ages smoking on spiromet- of longitudinal = 8.9 years for ric values in 1974 findings. primary school and data; decreased lung 12.6 years for high growth in smoking school groups boys who had had bronchitis before age 2 years. Kujala 1981 Finland, 1976 1,075 male military Significantlymduced None recruits, mean age = E'E'V, and +rometric 20 years flows when comparing NS with smokers at interview. Health Consequences 19 Surgeon General's Report from the findings from cross-sectional studies. Beck, Doyle, and Schachter (1982) examined white residents of Lebanon, Connecticut, in 1972 and 1978. Among male and female subjects aged 15 through 24 in 1972, smoking had reduced the increment of FEV, during the six-year follow-up interval. In a IO-year study in Sydney, Australia, Woolcock et al. (1984) periodically measured lung function in an initial cohort of 11,497 schoolchildren. Two groups of children were included: a younger cohort that was 8.9 years of age on average at enrollment and an older cohort aged 12.6 years on average at enrollment. The investigators followed up the cohort annually, measur- ing respiratory function and assessing symptoms, ill- nesses, and smoking. A small number of children were studied more intensively with the single-breath nitro- gen test. The effect of smoking was examined only in the older cohort. Cross-sectional assessment of these data showed that at 50 percent of vital capacity, smok- ers tended to have lower maximal expiratory flow than nonsmokers. For example, adolescents who smoked at least 10 cigarettes per week had about a 5 percent lower expiratory flow rate than nonsmokers. The investiga- tors concluded that abnormalities attributable to smok- ing were found in adolescents as young as age 14 and as soon as one year after beginning to smoke at least 10 cigarettes per week. They also concluded that smoking was more harmful for children and adolescents who had a history of respiratory illness, particularly asthma. A cohort study of children in East Boston, Massa- chusetts, has been informative on the effects of pgssive and active smoking on lung function (Tager et al. 1979, 1983,1985,1988). In 1974, the study enrolled a cohort of children aged five through nine who were sampled from schools in East Boston. The families of these children were then invited to participate in the initial survey and in periodic follow-up examinations that included a respiratory questionnaire and spirometry. Several relevant longitudinal analyses of the East Boston data have been reported (Tager et al. 1985,1987, 1988). Using data from the first seven follow-up ex- aminations, Tager et al. (1985) described the effect of smoking on the growth rates of FEV, and on forced expiratory flow (FED from 25 to 75 percent of forced vital capacity (FEF,,) in a group of 669 subjects aged 5 through 19 years at enrollment. Using a Markov-type autoregressive model, researchers found significant ef- fects of smoking on both measures of lung function. The model predicted that a child's smoking, beginning at age 15 and continuing through age 20, would reduce FEV, to 92 percent of the expected value and FEF,, to 90 percent of the expected value. A subsequent analysis using a nonparametric curve-smoothing method on these same data showed that male smokers had a smaller increase of FEV, at the end of the growth phase (a suggestion of a lower maximum lung function) than males who had not smoked; those who continued to smoke into early adulthood also showed no evidence of the plateau observed in never smokers before lung func- tion began to decline. Similar findings were reported for females. Relevant information is also available from a com- munity population study in Tucson, Arizona (Lebowitz and Holberg 1988). The Tucson cohort was derived from a population sample of 325 non-Hispanic white residents, originally sampled in 1972 when they were an average age of 8.8 years. Like the East Boston study, the Tucson study was directed primarily at passive smoking but also gathered information on active smok- ing by measuring FEV, and FEFsz. The Tucson study found effects of comparable magnitude with those ob- served in the East Boston study. Although these effects did not reach statistical significance in the Tucson data, they were in the same direction as those from East Boston, and the sample population was only half the size. Sherrill et al. (1992) examined the longitudinal effects of active and passive smoking on lung function in a cohort of New Zealand children observed from ages 9 through 15. Active smoking did not have statis- tically significant effects on FEV,, vital capacity, or FEV, /vital capacity (percent), but the numbers of regu- lar smokers were small. By age 15`43 percent reported occasional smoking (during the last year but not every day), but only 10 percent were daily smokers (smok- ing any number of cigarettes on a daily basis). Jaakkola et al. (1991) carried out an eight-year longitudinal study of lung function in a cohort of young adults aged 15 through 40 at enrollment. Of 1,044 enrolled, 391 were subsequently followed. Smoking was found to have a significant effect on change in FEV, during the study period, but the results were not re- ported by age interval. Respiratory Morbidity In adults, smoking is associated with increased morbidity, as indexed by such measures as use of out- patient medical services and absenteeism from work, and with increased respiratory morbidity, as indexed by frequency or severity of respiratory infections (USDHHS 1990). Because smoking has been shown to alter immune and inflammatory responses (U.S. De- partment of Health, Education, and Welfare [USDHEW] 1979b), these effects on an individual's defenses could 20 Health Consequences prpventing Tobacco Use Among Young People plausibly lead to increased frequency and severity of r~p~ato~ infections in smokers. Studies involving a wide age range of young people indicate that smoking increases respiratory mor- bidity (Table 3). A number of these studies compared mdical care by smokers and nonsmokers in settings ivhere all medical care was obtained at a single clinic. In one of the earliest studies, Haynes, Krstulovi~, and Bell (1966) examined the numbers of diagnoses for respira- tory tract illnesses among male students (aged 14-19 years) at a preparatory school. Nearly half of the stu- dents were smokers. AlI respiratory illnesses were more common in the smokers; the increase was greatest for the illnesses considered "severe." The findings of studies involving student nurses (Parnell, Anderson, Kinnis 1966) and military cadets (Finklea et al. 1971) were similar. A series of studies have included military recruits as subjects (Table 3); their ages ranged from 18 through 22. In the study of PoIIard et al. (1975), the rates of respiratory diagnoses were not significantly different between smokers and nonsmokers. In the more recent study of military recruits by Blake, Abell, and Stanley (19881, self-report of smoking was associated with in- creased risk for diagnosis of an upper respiratory tract infection during a 13-week basic training period. Kark and Lebiush (1981) and Kark, Lebiush, and Rannon (1982) examined attack rates for influenza and infIu- enza-like illnesses in Israeli military recruits and found that smoking was associated with an increased attack rate in both male and female recruits. Recently, in a study that examined adolescents and young adults who had sickle cell anemia, Young et al. (1992) found a strong relationship between cigarette smoking and acute chest syndrome, In sickle cell ane- mia patients, acute chest syndrome is characterized by fever, cough, chest pain, leukocytosis, and pulmonary infiltrates in the chest radiograph. All smokers in this study had a history of acute chest syndrome, whereas 65 percent of the nonsmokers did. Smoking also ap- peared to increase the frequency of sequelae of sickle cell lung disease. A study in the United Kingdom (Charlton and Blair 1989) associated smoking with increased absen- teeism from school among 2,885 children aged 12 and 13 years. Children who on an initial questionnaire reported regular smoking were more likely than non- smokers to be absent when a follow-up questionnaire was administered four months later. The authors inter- preted these findings as showing a higher rate of minor ailments in children who smoked; however, the design could not exclude other plausible explanations (such as truancy) for the difference. In a survey of adolescents invited for an overall evaluation in three general prac- tices in the United Kingdom, smokers reported a higher prevalence of health problems than nonsmokers (25 percent vs. 16 percent, p = .06) (Townsend et al. 1991). Epidemiologic Evidence of Nonrespiratory Effects Cardiovascular Disease In adults, cigarette smoking is a cause of coronary heart disease, arteriosclerotic peripheral vascular dis- ease, and stroke (USDHHS 1989). Although these diseases rarely occur in children and adolescents, au- topsy studies of young male victims of combat during the Korean and Vietnam conflicts and community-based autopsy studies of adolescents and young adults have shown that atherosclerosis begins in childhood and may become clinically significant in young adulthood (McNamara et al. 1971; Enos, Holmes, Beyer 1986; Strong 1986). Several autopsy-study series Iink cigarette smok- ing to the occurrence and extent of atherosclerosis in young adults. Strong and Richards (1976) described the association of cigarette smoking with atherosclerosis in 1,320 men from the New Orleans area. In the youngest group (aged 25 to 34 years), the development of athero- sclerosis in the coronary arteries and the abdominal aorta was consistently greater with higher levels of smoking. More recently, an eight-community study by the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) Research Group (1990) found associa- tions of smoking with atherosclerosis in 390 males aged 15 through 34 years who died of violent causes (e.g., accidents, homicides, suicides). In this study, lipids were measured in postmortem serum, and smoking was assessed by the level of serum thiocyanate. After controlling for lipid levels, age, and race, a multiple regression analysis revealed a significant association between smoking and atherosclerosis (i.e., having raised lesions greater than or equal to 5 percent of the intimal surface area) in the abdominal aorta. A multipIe logistic analysis controlling for the same factors found that smoking was a significant predictor of atherosclerosis in both the abdominal aorta and the right coronary artery. The Bogalusa Heart Study is an epidemiologic study of cardiovascular disease risk factors encountered from birth through age 26. Among deceased subjects whose average age was 18 years, cigarette smoking was not associated with aortic fatty streaks or involvement of the coronary arteries with atherosclerosis (Newman et al. 1986;Freedmanetal. 1988). However,insubjects who Health Consequences 21 Surgeon General's Repot Table 3. Published studies of the effects of smoking on respiratory morbidity among young people, various countries, 1963 -1987 Reference* Haynes, Krstulovic, Bell 1966 Location/year New Jersey' Study population 191 male prep school students aged 14-19 years Kark and Lebiush 1981 Israel, 1979 Female military recruits, mean age = 18.5 years Blake, Abell, Stanley 1988 Georgia, 1982 1,230 Army recruits, most aged < 22 years Schwartz and Zeger 1990 California+ 100 student nurses *Listed chronologically by publication date. `Year not provided. 22 Health Consequences pr,.l,crrting Tobacco Use Among Young People Health effect Prevalence (%I by smoking status Nonsmoker Occasional smokert Regular smoke@ Annual illness rates"/ 10 students All respiratory Severe respiratory Number of cigarettes smoked peE day 0 5 1 pack > 1 pack Incidence rate** (per 100 school years) Upper respiratory Outpatient Hospital 52.5 59.9 67.0 7.6 12.0 10.2 Lower respiratory Outpatient Hospital 2.5 3.0 6.8 0.4 0.7 0.9 Attack of influenza-like morbiditya Occasional/regular smoke@ Never/past smoker 60% 40% General Findings: Relative risk = 1.46 for upper respiratory infection for smokers versus nonsmokers. Illnesses ascertained by visits to clinics. . General Findings: Smoking significantly associated with incidence of cough and phlegm. (h-rent amount smoked significantly predicted duration of an episode of phlegm or chest discomfort. fSmoked at least 1 cigarette or pipe per week. $moked at least 1 cigarette or pipe per day. `Illness rates based on infirmary visits during a school year. `[ltness incidence based on records of the health service. **Incidence rates based on self-administered questionnaire. -Respiratory-related (similar symptoms) visits to dispensary, with one week grouped. "Based on self-administered questionnaire. @These categories were not defined. MIllness occurrence based on medical records and serology. Health Consequences 23 Surgeon General's Report died after age 20, smoking appears to have been related to atherosclerosis (Berenson et al. 1992). Smoking among young people has been associated with serum lipid profiles in a pattern predictive of in- creased risk for cardiovascular diseases. In a published meta-analysis of studies on children who smoke, Craig et al. (1990) found that among 8- through lPyear-olds, smoking increased levels of low-density lipoprotein cho- lesterol by 4 percent, triglycerides by 12 percent, and very-lowdensity lipoprotein cholesterol by 12 percent. Levels of highdensity lipoprotein (HDL) cholesterol were reduced by 9 percent. These changes were comparable to-and of larger magnitude than-those observed in smoking adults. Physical Fitness Even among young people trained as endurance runners, smoking appears to compromise physical fitness in levels of both performance and endurance. Cigarette smoking reduces the oxygen-carrying capacity of the blood and increases both heart rate and basal metabolic rate-changes that counter the benefits of physi- cal activity in a direct relation to the duration of smoking and the number of cigarettes regularly smoked (Royal College of Physicians of London 1992). In a study of 19- year-old army conscripts (N = 6,500), those who smoked ran a significantly shorter distance in 12 minutes and took significantly longer to sprint 80 meters than their nonsmoking counterparts (Marti et al. 1988). In the same study, the smokers among 4,100 joggers in a 16kilometer' race were consistently slower than the nonsmokers. Young adult smokers also have chronic, mild ad- verse cardiovascular physiologic changes, including di- minished exercise performance on standard treadmill testing and blunted heart rate response to exercise (Sidney et al. 1993). The left ventricular mass is increased in young adult smokers, and their resting heart rates are two to three beats per minute more rapid than nonsmok- ers' (Gidding et al. 1992). Health Outcomes in Pregnancy Cigarettesmokingduringpregnancyhasbeenlinked with a variety of adverse outcomes KJSDHHS 1989,199O). Early reports of the Surgeon General KJSDHEW 1971, 1973,1979a) concluded that smoking by a mother during pregnancy retards fetal growth and may cause fetal death late in pregnancy as well as infant mortality. The 1977- 1978 report KJSDHEW 1979a) further concluded that smoking during pregnancy has dose-response relation- ships with abruptio placenta, placenta previa, bleeding during pregnancy, premature and prolonged rupture of placental membranes, and preterm delivery. The comprehensive reviews of the 1979 and 1980 reports (USDHEW 1979a; USDIIIIS 1980) concluded that the risk of spontaneous abortion increases with the amount of smokingand thattheriskofsuddeninfantdeathsyndrome (SIDS) is increased by maternal smoking. A more recent study confirms the increased risk of SIDS with maternal smoking (Schoendorf and Kiely 1992). Impaired fertility was linked to smoking in the 1980 report (IJSDIIIIS 1980). These adverse health effects of smoking on reproduction have not been specifically investigated in young women in the lO- through 20-year age range. Epidemiologic Evidence of the Health Effects of Passive Smoking The health effects of passive smoking were com- prehensively addressed in the 1986 report of the Surgeon General (USDHHS 1986a) and in a report of the National Research Council (1986). These reviews and subsequent reports (Samet, Cain, Leaderer 1991; USEPA 1992) have demonstrated that exposure to parental smoking during childhood significantly increases the occurrence of lower respiratory illnesses during the first years of life, in- creases the frequency of chronic respiratory symptoms, and reduces the rate of lung growth during childhood and adolescence. Evidence is accumulating to suggest that smoking by parents increases the severity of child- hood asthma (USDHHS 1991b; Samet, Cain, Leaderer 19911, as indicated by the need for medication and hospi- tal treatment. SIDS, the most common cause of death in the first year of life, has been linked to parental smoking in several epidemiologic studies. Children of parents who smoke have a twofold increased risk of dying of SIDS; this relationship appears to be dose-related (Schoendorf and Kiely 1992; Malloy et al. 1988). The evidence on passive smoking and respiratory health was recently reviewed by the USEPA (1992). This review confirmed that ETS is causally linked to lung cancer. Janerich et al. (1990) noted that approximately 17 percent of lung cancers among nonsmokers can be attrib- uted to high levels of ETS during childhood and adoles- cence. The USEPA report also concluded that exposure to ETS causes lower respiratory illness in infants and young children; this finding is stronger than that of the 1986 Surgeon General's report, which did not character- ize this association as causal. The agentis report also inferred from its data that childhood exposure to ETS reduced lung function, increased respiratory symptoms, caused middle ear effusion, and exacerbated asthma. For example, the report estimated that ETS exposure exacerbates symptoms of asthma in about 20 percent of the two million to five million asthmatic children in the United States. The report also hypothesized that ETS may be associated with the onset of asthma. 24 Health Consequences prt7w ting Tobacco Use Among Young PeopZe Many chronic changes in cardiovascular physiol- I have been observed in children exposed to ETS. Tse changes include lower HDL cholesterol, increased carboxyhemoglobin concentration, and increased rtd-cell 2.3diphosphoglycerate, as well as physiologic response suggesting mild, chronic hypoxemia (Moskowitz et al. 1990). ETS is also known to increase platelet aggregation (Glantz and Parmley 1991). The effect of peer smoking-as a source of ETS- on nonsmoking children has not been studied but may also be a health risk. Adult Health hpkations of Smoking Among Young People Respiratory Diseases As was discussed previously, sustained smoking during adulthood is associated with the development of C()PD and the progressive loss of lung function (USDHHS 1984,199O). Evidence suggests that smoking during childhood may increase the risk for developing CORD in adulthood as well as at an earlier age. The &dt who smoked during childhood may have experi- enced early inflammatory changes--childhood smoking is known to reduce lung growth-and thereby not at- tained the level of function achieved during the normal growth and development of the lungs. Any age-related decline in lung function during adulthood would thus start from a lower level-and might begin at a younger age-than declines observed in adults who have never smoked. In fact, the proportionate impeding effect of chiIdhood smoking on lung growth greatly.exceeds the loss of lung function associated with smoking during `rdulthood (Tager et al. 1985,1988). If one or both parents of an adolescent smoke, the cffccts of parental smoking on early childhood respira- tory illnesses and on the growth of lung function may increase the risk of COPD. Illnesses in the lower respira- tor-v region during childhood are a suspected risk factor for-COPD (Samet, Tager, Speizer 19831, and passive smoking reduces the rate at which lung function grows (USDHHS 1986a). Cardiovascular Disease In adults, cigarette smoking has been causally associated with coronary heart disease, arteriosclerotic peripheral vascular disease, and stroke (USDHHS 1983, 1989). Smoking contributes to increased risk for coro- nary heart disease probably through at least five in- terrelated processes, including the development of atherosclerosis (USDHHS 1990). It is likely that the earlier the age at which one starts to smoke, the earlier the onset of coronary heart disease. The recent evidence from the PDAY Research Group shows more athero- sclerosis in young smokers than in young nonsmokers. The unfavorable effects of smoking on lipid levels in children may contribute to the development of athero- sclerosis in young adulthood. Cancer The multistage concept of carcinogenesis implies that the risk of smoking-related cancers is strongly de- pendent on the duration and intensity of smoking (Armitage and Doll 1954; Doll 1971; Taioli and Wynder 1991). The relevant epidemiologic data and mathemati- cal analyses are most abundant for lung cancer. Both epidemiologic and experimental evidence suggest that the risk for lung cancer varies more strongly with the duration of cigarette smoking than with the number of cigarettes smoked Veto 1977; Doll and Peto 1978). Analy- sis of data from a cohort study of British doctors showed that lung cancer incidence increased with the fourth or fifth power of duration of smoking but with the second power of number of cigarettes smoked daily (Doll and Peto 1978). Although these data can be adequately de- scribed by alternative mathematical models that give lesser weight to duration (Moolgavkar, Dewanji, Luebeck 1989), the dependence of lung cancer risk on duration of smoking implies that starting smoking at an earlier age increases the potential number of life-years of smoking and therefore increases lung cancer risk. If one assumes, for example, that lung cancer risk rises exponentially as a function of the duration of smoking, then the risk at age 50 for a person who began smoking regularly at age 13 is 350 percent greater than that for a 50-year-old who started smoking at age 23. Similar analyses have not been done for other smoking-related sites of cancer. Nevertheless, for most smoking-related cancers, the risk rises with the duration of smoking (USDHI-IS 1982,1989,1990; Intema- tional Agency for Research on Cancer 1985). One could Health Consequences 25 Surgeon General's Report infer that the risk of smoking-related cancer for sites other than the lungs would increase, at a given adult age, in inverse proportion to the age an adolescent beg+ smoking. Recent studies indicate that earlier onset of cigarette smoking is also associated with heavier smok- ing (Taioli and Wynder 1991; Escobedo et al. 1993). Heavier smokers are not only more likely to experience tobacco-related health problems, they are the least likely to quit smoking (Hall and Terezhalmy 1984; USDHHS 1989). Early use of cigarettes thus appears to influence intensity as well as duration of use and increases the potential for long-term health consequences. Nicotine Addiction in Adolescence Introduction Nicotine dependency through cigarette smoking is not only the most common form of drug addiction but the one that causes more death and disease than all other addictions combined (USDHHS 1988). Most human research on nicotine addiction has been conducted with adult subjects, but the basic biologic processes that underlie this dependency appear to be similar in ad- olescents and adults. The research literature on nicotine addiction examines its chemistry and addiction poten- tial, its severity, and its pathophysiology and clinical course. Background and Nomenclature Drug addiction is the term most widely used to. label various medical and social disorders related to the compulsive ingestion of psychoactive chemicals. The primary criteria for drug dependence are that the behav- ior is highly controlled or compulsive, the chemical is one whose mood-altering or psychoactive effects are central elements of the drug's activity, and the drug itself has the demonstrated capability of reinforcing behavior (Table 4). The American Psychiatric Association (APA) has identified two medical disorders that pertain to nice tine addiction: nicotine dependence and nicotine withdrawal (APA 1987). Nicotine dependence is classified as a psychoactive substance-use disorder characterized by "a cluster of cognitive, behavioral, and physiologic symptoms that indicate that the person has impaired control of psychoactive substance use and continues use of the substance despite adverse consequences" (APA 1987, p. 166). In the case of nicotine, the most common form of use is cigarette smoking, in part because the rapid ab- sorption of nicotine through the processes of smoking `leads to a more intensive habit pattern that is more difficult to give up" than other forms of use (APA 1987, p. 181). Nicotine dependence also occurs through other routes of delivery, including smokeless tobacco and nicotine gum. 26 Health Consequences Nicotine withdrawal, an organic mental disorder induced by the removal of psychoactive substance, is described as "a characteristic withdrawal syndrome due to the abrupt cessation of or reduction in the use of nicotine-containing substances (e.g., cigarettes, cigars and pipes, chewing tobacco, or nicotine gum) that has been at least moderate in duration and amount. The s-yndrome includes craving for nicotine; irritability, frustration, or anger; anxiety; difficulty concentrating; restlessness; de creased heart rate; and increased appetite or weight gain" (APA 1987, p. 150). Physical dependence refers to the condition in which withdrawal symptoms have been observed. Physical dependence can complicate the process of achieving and Table 4 . Criteria for drug dependence Primary criteria Highly controlled or compulsive use Psychoactive effects Drug-reinforced behavior Additional criteria Addictive behavior often involves the following: Stereotypic patterns of use Use despite harmful effects Relapse following abstinence Recurrent drug cravings Dependence-producing drugs often manifest the following: Tolerance Physical dependence Pleasant (euphoric) effects Source: Adapted from USDHHS (1988). prcyvwting Tobacco Use Among Young People maintaining drug abstinence, and the symptoms can be so unpleasant as to precipitate relapse (Jaffe 1985; USDHHS 1988). In surveys by the National Institute on Drug Abuse (NIDA), withdrawal and inability to main- tain abstinence are COIYUIIO~~~ attributed to cigarette smok- ing and heroin ux (USDHHS 1988). The majority of people monitored who reguIarly use other addictive drugs (including cocaine and marijuana) report that they have not experienced withdrawal, even though many of these people feel dependent and have been unable to maintain abstinence (USDHHS 1988). Severity of Nicotine Addiction Tobacco-delivered nicotine can be highly addic- tive. Each year, nearly 20 million people try to quit smoking in the United States (USDHHS 1990), but O~Y about 3 percent have long-term success (Pierce et al. 1989; Centers for DiseaseControland Prevention [CDCJ, Office on Smoking and Health, unpublished data). Even among addicted persons who havelost a lung because of cancer or have undergone major cardiovascular sur- gery, only about 50 percent maintain abstinence for more than a few weeks (West and Evans 1986; USDHHS 1988). In a 1991 Gallup Poll, 70 percent of current smokers reported that they considered themselves to be "addicted" to cigarettes (Gallup Organization 1991). These findings are consistent with data from NIDA's I985 National Household Survey on Drug Abuse (NHSDA), which showed that 84 percent of 12- through 17-year-olds who smoked one pack or more of cigarettes per day felt that they "needed" or were "dependent" on cigarettes (Henningfield, Clayton, Pollin 1990). The NHSDA data show that young smokers develop toler- ance and dependence, increase the amount they smoke, and are unable to abstain from nicotine. These findings suggest that the addictive processes in adolescents are fun- damentally the same as those studied in adults (USDHHS 1988; Henningfield, Clayton, Pollin 1990). Several studies have found nicotine to be as addic- tive as heroin, cocaine, or alcohol (Henningfield, Clayton, Eollin 1990; Henningfield, Cohen, Slade 1991; Kozlowski et al. 1993). Moreover, because the typical pattern of tobacco use entails daily and repeated doses of nicotine, addiction is more common among all users than is true of other drug use, which tends to occur on a far less frequent basis (USDHI-IS 1988). For example, only about 10 to I5 percent of current alcohol drinkers are consid- ered problem drinkers, but approximately 85 to 90 per- cent of cigarette smokers smoke at least five cigarettes every day (Henningfield, Cohen, Slade 1991; Evans et al, 1992; Henningfield 1992b; Kozlowski et al. 1993). Only 2 to 3 percent of smokers (or about 7 to 10 percent of those who try quitting) stop smoking for one year (CDC 1993a), and most daily smokers report that they feel dependent on smoking and have experienced with- drawal symptoms (USDHHS 1988; Henningfield, Clayton, Pollin 1990). Chemistry and Addiction Potential Many behaviors that become regular, habituaI, and hard to give up involve the ingestion of a substance. What sets drug addictions apart from less harmful habits is that the ingested substance releases a psychoactive drug with the demonstrated potential to addict. Several thousand chemicals are present in cigarette smoke. Some may conceivably modulate nicotine's addictive effects, but the fact that different forms of nicotine delivery can be substituted for one another(e.g., nicotine gum or transdermal patch in place of cigarettes) suggests that nicotine is critical in the addiction process (Henningfield 1984; Benowitz 1988; USDHHS 1988; Russell 1990). Nicotine is a naturalIy occurring aIkaloid present in varying concentrations in different strains of tobacco. Most cigarettes sold in the United States contain about 8 to 9 milligrams of nicotine, of which the smoker typically in- gests 1 to 2 milligrams per cigarette (Benowitz et al. 1983; USDHHS 1988). Nicotine is both a lipid- and water- soluble molecule that can be rapidly absorbed in a mildly alkaline environment through the skin or the Iining of the mouth and nose. Because of the massive area for absorp- tion in the alveoli of the lungs, nicotine inhaled deeply is almost immediately extracted from the smoke into the pulmonary veins; this sudden spike or bolus of nicotine is delivered to the brain, via arterial circulation, in approxi- mately 10 seconds (USDHHS 1988). In contrast, although smokeless tobacco has much higher levels of nicotine than cigarettes, the delivery of the drug is much more gradual; the effect peaks within approximately 20 minutes of use (Benowitz et al. 1988). The peak for nicotine replacement medications is even slower-30 minutes or longer for nicotine gum (Benowitz et al. 1988), severaI hours for the four commercially available transdermaI patch systems (Palmer, Bucklet, Faulds 1992). In fact, because of the efficiency of the pulmonary route in extracting nicotine from inhaIed tobacco smoke, nicotine may be 10 times more concentrated in arterial blood than in simultaneously sampled venous blood; these levels are much higher than those produced by nicotine replacement medications (Henningfield, London, Benowitz 1990). As vehicles for nicotine delivery, tobacco products are convenient to use, and they provide the experienced user with a means of regulating dose level. Such control does not, however, protect the user against drug depen- dency, since tobacco products appear to deliver the opti- mal addiction potential (or abuse liability) of nicotine. Chemicals can be tested for their addiction potential to Health Consequences 27 Surgeon General's Report determine if they are psychoactive and if they can serve as reinforcers in animals and humans (Brady and Lukas 1984; USDHHS 1988; Fischman and Mello 1989; Henningfield, Cohen, Heishman 1991). These methods to test for abuse liability are reliable enough for the Food and Drug Administration (FDA) and the World Health Organization (WHO> to use them to develop policies regarding regulation of new drugs with possible addic- tion potential (USDHHS 1988; Barcelona Conference 1991). Nicotine meets the criteria for addiction potential in all of the standardized tests used by the FDA and the WHO (USDHHS 1987, 1988, 1991a). In humans and animals, nicotine produces discrete subjective effects more similar to those produced by cocaine than to those pro- duced by sedatives, and nicotine injections are biologi- cally reinforcing to humans and to at least five animal species (Henningfield, Miyasato, Jasinski 1985; Henningfield and Goldberg 1988; USDHI-IS 1988). Such. findings confirm the conclusion of the 1988 report of the Surgeon General: nicotine is a drug with a liability for addiction (USDHI-IS 1988). Pathophysiology of Nicotine Dependence The pathophysiology of drug dependence and the clinical course of nicotine and other drug dependencies have been described in detail elsewhere (Gaffe 1985; USDHHS 1988; Benowitz 1992; Henningfield 1992a). In brief, exposure to a psychoactive chemical leads to re- petitive self-administration because of the chemical's capacity to condition behavior. This powerful condi- tioning action of nicotine is mediated at least in part by the activation of nicotinic receptors in the brain (USDI-IHS 1988; Bock and Marsh 1990) and the modulation of levels of hormones such as epinephrine (adrenaline) and corti- sol (Pomerleau and Pomerleau 1984; Sachs 1987; USDHHS 1988). The mesolimbic dopaminergic reward system, which mediates the addicting actions of cocaine, is also thought to be involved in producing nicotine's addictive effects (Pomerleau and Pomerleau 1984; USDHHS 1988; Bock and Marsh 1990; Balfour 1991a, b; Benwell and Balfour 1992). Behaviors that are followed by intense neural activation can become highly persistent and diffi- cult to modify (Pomerleau and Pomerleau 1984; Jaffe 1985; USDHHS 1988). Each year, the daily cigarette smoker may experience 50,000 to 100,000 such pairings of puffing on cigarettes and resultant effects in the brain, thus establishing a persistent need for cigarette smoking. Tolerance Tolerance refers to a diminishing response to a drug through repeated exposures (Gaffe 1985; USDHHS 1988). Tolerance is often demonstrated when increased dose levels are required to obtain the effects formerly produced by lower doses. Tolerance to nicotine appears to be acquired as people progress from initially smoking a few cigarettes to smoking greater numbers of cigarettes more often (see `Initiation Continuum of Smoking" and "Adult Implications of Adolescent Smoking" in Chapter 3 and "Developmental Stages of Smoking" in Chapter 4). The development of tolerance to the aversive effects of nicotine, such as nausea and dizziness, may also facili- tate the development of dependency (USDHHS 1987; Shiffman et al. 1990; Shiffman 1989,199l; McNeill, Jarvis, West 1987). Tolerance of nicotine increases over time; experienced smokers can self-administer doses of nico- tine that would make nonsmokers ill. The tolerance the nervous system develops to nico- tine exposure can be at least partially overcome by increasing the dose. This effect was studied near the beginning of the 20th century and has been the subject of considerable study since then (Langley 1905; USDHHS 1988; Benowitz and Jacob 1993). Tolerance to various behavioral, physiologic, and subjective effects of nicotine has been studied (USDHHS 1988). For example, administering nicotine to a tobacco-deprived cigarette smoker can produce a substantial increase in heart rate and measures of euphoria, along with a decrease in the strength of the knee reflex. With repeated doses, the heart rate stabilizes at a level between that produced by the first dose and that which occurs when nicotine- deprived; subjective effects are minimaI, and the knee reflex may become normal (Domino and Von Baum- garten 1969; USDHHS 1988; Swedberg, Henningfield, Goldberg 1990). Some tolerance of nicotine is lost each night as the smoker's nicotine levels fall; the nicotine from the first few cigarettes of the day produces effects on heart rate, mood, and other measures that are stronger than the effects produced by subsequent doses during the day (USDHHS 1988). Repeated exposure to nicotine leads to morphological changes in the brain that cause the devel- opment of new binding sites for nicotine receptors, which mediate the effects of nicotine (Bock and Marsh 1990; USDHHS 1988,199la). Animal research has shown that nicotine exposure results in an increased expression (defined as up-regula- tion) of nicotine receptors in various regions of the brain (Ksir et al. 1985; Morrow, by, Creese 1985; Nordberg et al. 198.5; Schwartz and Kellar 1985; Ksir, Hakan, Kellar 1987). Prenatal exposure to nicotine also produces up regulation of nicotine receptors in tissue collected from newborn animals (Slotkin, Orband-Miller, Queen 1987; Slotkin et al. 1991; Smith, Seidler, Slotkin 1991). These data suggest the broad applicability of this up-regulation effect, which may be one of the ways in which tolerance of nicotine occurs CUSDI-II-IS 1989). 28 Health Consequences prarenting Tobacco Use Among Young People Humanresearchismorelimitedthananimalre search in this area, but there is evidence that cigarette smoking is associated with upregulation of nicotine receptors in the human brain. Balfour (1989, 1991a) has conducted a series of studies that included the examination of postmortem brain tissue from smokers and nonsmokers. He and others found evidence of signifi- cantly elevated concentrations of nicotine binding sites as well as smoking-related changes in other binding sites (such as 5hydroxytryptamine) (Benwell, Baifour, Ander- son 1988; Balfour 1989,199la; Grant, McMurdo, Balfour 1989; Bock and Marsh 1990). Morphologic changes in the nervous system are presumed to reflect part of the bodfs adaptation (resulting in tolerance and physical depen- dence) to a prolonged exposure to nicotine (Marks and Collins 1982; Marks, Burch, Collins 1983; Marks et al. 1985, 1986;h4ar~,Stitzel,Collins1985,1986,1987;USDHHS1988). Physical Dependence Nicotine administered to animals and humans prD- duces altered spontaneous electroencephalograph (EEG) and evoked electrical potentials of the brain, altered local cerebral glucose metabolism, modulation of hormonal output by the adrenal glands, increased heart rate, and changes in skeletal muscle tension (USDHHS 1988). Most, if not all, of these effects are related to the dose of nicotine given, and tolerance develops to differing degrees across these effects. After a period of nicotine exposure that is assumed to be at least several weeks (APA 1987), physi- cal dependence on nicotine develops. The dependent person then appears to be functioning normally when under the influence of nicotine; conversely, the person may report feeling "abnormal" or "not right" when de- prived for more than a few hours (Casey 1987). Although basic pharmacologic research on nico- tine has been conducted primarily with adults, most people begin to smoke in adolescence and develop char- acteristic patterns of nicotine dependence before adult- hood (USDHHS 1988,199la). That adolescents develop physical dependence, as evidenced by their experience of withdrawal symptoms, has been well documented by the NHSDA (USDHHS 1991~). Moreover, quantitative characteristics of the withdrawal syndrome appear to be the same in adolescents and adults (McNeill et al. 1986; McNeill, Jarvis, West 1987). The magnitude of the withdrawal syndrome is related to the previous level of nicotine intake, although differences in just a few cigarettes a day may not be correlated with the severity of the syndrome (Killen et al. 1988; USDHHS 1988). Environmental context is also a factor; in a novel environment (e.g., a hospital setting), the symptoms of nicotine withdrawal may be less than in the smoker's usual environment, with its various psychological cues for smoking (Hatsukami, Hughes, Pickens 1985). The time course of withdrawal symptoms varies among individuals and for different responses. Most withdrawal symptoms peak within the first few days of nicotine abstinence and then begin to recover along a variable course; the most severe total withdrawal syndrome usually lasts about three to four weeks (LJSDHHS 1988; Gross and Stitzer 1989). For example, certain measures of brain function (such as P3OO-evoked electrical potential) recover within a few days, but others may take weeksor more (such as NlOO-evoked potential, hunger, and craving). Powerful urges to smoke may recur for many years (Hughes and Hatsukami 1986; USDHHS 1988). Although questions remain, the pathophysiology of nicotine dependence clearly `&olves the brain, the endocrine system, and behavior, and the process begins when cigarette smoking is initiated. Moreover, although the effects of nicotine administration and deprivation are complex, they are orderly and are related to factors such as the amount of nicotine administered and the time since the last dose. The Clinical Course of Nicotine Dependence Like other drug addictions, nicotine dependence is a progressive, chronic, relapsing disorder. The level of dependence on nicotine in adults has been found to be inversely related to the age at initiation of smoking when measured by diagnostic criteria (APA 1987) of the APA (Breslau, Fenn, Peterson 1993) and by the Fagerstrtim Tolerance Questionnaire Score (Henningfield et al. 1987). As is true for most drug addictions, tobacco use is not always constant from initiation on; the process of graduation from first use to addiction can take months or even years (USDHHS 1988). In fact, initial experiences with tobacco, as with other addictive substances, are sometimes negative and require social pressures and other factors to maintain exposure until the addiction develops (Haertzen, Kocher, Miyasato 1983). The per- centage of people who progress from smoking a few cigarettes to smoking at a regular, addictive level has been estimated to range from 33 to 94 percent. For example, Russell (1990) has reported that a survey of adults in Great Britain in the mid-1960s indicated that 94 percent of those who smoked more than three cigarettes became `long-term regular smokers." These data, which precede widespread public awareness of the hazards of smoking, may have a limited applicability to current smoking behavior. Recently collected data in the United States and Great Britain suggest that between 33 and SO percent of people who try smoking cigarettes escalate to regular patterns of use &I&&man Leventhal, Glynn 1984; McNeilll991; Henningfield, &hen, Slade 1991). Health Consequences 29 Surgeon General's Report The chronic phase of the addictive process is highly resistant to substantial modification. For example, ef- forts to reduce tobacco smoke and nicotine exposure by smoking cigarettes with lower ratings of nicotine deliv- ery or to smoke fewer cigarettes are usually partially or completely thwarted by compensatory changes in how the cigarettes are smoked; smokers may compensate for "cutting back" by inhaling more deeply or smoking the cigarette farther down to its more potent and more toxic end (Kozlowski 1981,1982; benowitz et al. 1983; benowitz and Jacob 1984; USDHHS 1988). Abstinence from smok- ing is generally short-lived; the majority of persons who quit on their own or in minimally supportive interven- tions appear to relapse within one week of their last cigarette (Kottke et al. 1989). In fact, in testament to the persistence of addiction, nearly one-third of those who have abstained for one year after quitting relapse later (USDHHS 1990; Giovino 1991). These patterns of relapse are similar to those observed with other drug addictions. Several potential predictive measures of the sever- ity of addiction in a person may forecast the severity of withdrawal and the outcome of an attempt to quit. These measures, which have been discussed in detail in the 1988 report of the Surgeon General (USDHHS 19881, include cotinine level in biological fluid such as saliva, blood, or urine; number of cigarettes smoked per day; score on the Fagerstrom Tolerance Questionnaire; and number of symptoms attributed from the Diagnostic and Statistical Manual of Mental Disorders (APA 1987). These measures tend to predict, although not perfectly, the difficulty of achieving abstinence, the severity of with- drawal symptoms, the rapidity of relapse, and the effi- cacy of replacement therapy (USDHHS 1988). One final source of vulnerability to nicotine depen- dence appears to be genetic predisposition. Research with animals has shown that the amount of upregulation (increased binding in the brain) of nicotine receptors after Smoking as a Risk Factor for Other Drug Use nicotine exposure is related to genetic constitution, as are certain behavioral and physiologic effects (Marks et al. 1989; Collins 1990). Data from studies with human twins have yielded indices of heritability for cigarette smoking similar to those for drinking alcohol (Hughes 1986; Kozlowski 1991; Carmelli et al. 1992). Nondrug Factors in Nicotine Dependence Nondrug factors can affect the prevalence of drug addiction in society as well as its severity in individuals. Some of the factors are the same as those that determine the prevalence and severity of other medical disorders resulting from exposure to toxins. Among the most important factors in determining the prevalence of drug addiction is the exposure to the addicting substance (USDHHS 1988). This factor is no less important in the spread of drug addiction than it is in the spread of disorders such as acquired immunodeficiency syndrome, malaria, and influenza infections. Moreover, social fac- tors can determine the type and frequency of exposure to the etiologic agent, as well as the time frame over which exposure continues. Many nondrug factors associated with both abstinence and relapse appear to operate simi- larly across addictions. These factors include illness induced by drug dependence (which will at least tempo rarily interrupt drug use), ability to learn to manage cravings, social reinforcements for abstinence, availabil- ity of the substance, cost of the substance, and perception of the risk of using the substance (USDHHS 1988). Persons vary in their vulnerability to nicotine and other drug addiction, just as they vary in their vulnerabil- ity to other medical disorders; some people show a high degree of resistance to the disorder despite multiple exposures to the agent, and others very quickly become addicted (USDHHS 1988). Psychosocial factors affecting the vulnerability of the young and the onset of tobacco use are discussed in Chapter 4. Introduction The 1988 Surgeon General's report (USDHHS 1988) showed that among adolescents, cigarette smoking is a risk factor in the development of alcohol use and illegal drug use. The nature of the interrelationship be- tween tobacco and other drug use is complex; in several possible ways, tobacco use may heighten the probability that a young person will use other drugs (Slade 1993; see "Smoking and Other Drug Use" in Chapter 3 and "Behav- ioral Factors in the Initiation of Smoking" in Chapter 4). Progression of Drug Use Kandel(1975) found that studies of the progression of drug use in the 1970s showed that cigarette smoking and alcohol use generally preceded marijuana smoking and other illegal drug use. In fact, Kandel's study 30 Health Consequences PrlywI tittg Tobacco Use Among Young People ronclud~ that virtually everyone who used illegal drugs such as marijuana or cocaine had previously used bgareHe, alcohol, or both. These findings, primarily among white youths, have been repeatedly extended and replicated (e.g., Fleming et al. 1989; Kandel and \I'amagWhi 1993). More recent data hrom the Monitoring the Future prop (MTFP) by NIDA. (USDHHS 1988) confirm that illegal drug use is rare among those who have never smok& and that cigarette smoking is likely to precede the use of alcohol or illegal drugs. The 1985-1989 MTFI' show& that first use of tobacco had occurred at the same age as first use of alcohol for 33 percent of the sample; cigarettes were used before alcohol by 49 percent of the simple. The same survey showed that among those who had used both cigarettes and marijuana, 23 percent be- Ron using both in the same year, and 65 percent smoked. c@rettes before marijuana. The latter relationship was more pronounced for cocaine: 98 percent of persons who had used both cocaine and cigarettes smoked cigarettes first (see Tables 24-26 in Chapter 3). These findings were extended in another longitu- dinal study that assessed 12-, 1.5, and I&year-olds in New Jersey and reinterviewed them at three-year inter- vals (USDHHS 1987). This study showed that among 15 year-olds, the use of cigarettes, alcohol, or marijuana was the strongest predictor of cocaine use when these same Persons were reinterviewed three years later; at that time, the persons using cocaine were likely to be using cigarettes and alcohol as well. Cigarette smoking in combination with alcohol use appears to be especially predictive of illegal drug use. A longitudinal study by Yamaguchi and Kandel (1984) examined initial data from students in the tenth and eleventh grades in New York State in 1971. When the authors reevaluated the same students in 1981 (av- erage age, 25 years>, the most common sequence of drugs used was alcohol, cigarettes, marijuana, illegally used psychoactive or prescription drugs, and other ille- gal drugs. The investigators found that for 87 percent of the men, alcohol use preceded marijuana use; alco- hol and marijuana use preceded other illegal drug use; and use of alcohol, cigarettes, and marijuana preceded the use of other psychoactive drugs. For 86 percent of the women, a similar, but not identical, pattern emerged: alcohol or cigarettes preceded marijuana; alcohol, ciga- rettes, and marijuana preceded other illegal drugs; and alcohol and either cigarettes or marijuana preceded other psychoactive drugs. These findings were repli- cated with 1,108 high school seniors in New York in 1988 (Kandel and Yamaguchi 1993). This study confirmed the importance of cigarette and/or alcohol use in the Progression of illegal drug use, with early cigarette use being of particular importance in the develop ment of other drug use among females. Early onset of cigarette smoking and /or alcohol use was a strong pre- dictor of further drug use. The relationship between alcohol use and cigarette smoking is more complex than would be suggest& by examining any one survey. Jn some studies, alcohol is more likely to precede than to follow cigarette smoking. This variability might be explained by the d&ring study criteria for alcohol use. For example, among many adoles- cents, alcohol consumption is characterized by the occa- sional light use of beer or wine-a pattern that often neither escalates into patterns of heavy drinking nor pre- dicts other drug use fKande1, Marguihes, Davies 1978; Huba, Wingard, Bentler 1981; 0'Donnell and Clayton 1982). This finding is consistent with the observation that approximately 85 percent of people who drink alcoholic beverages do so in patterns that do not meet criteria for abuse (USDHHS 1988). On the other hand, consumption of `hard liquor," sometimes accompanied by heavy drink- ing patterns, appears to develop either along with or following the development of regular patterns of cigarette smoking (Kozlowski et al. 1993; DiFranza and Gum 1990). These observations are consistent with the iind- ings of the 1985 NHSDA, which showed that among 12- through 17-year-old adolescents who had never smoked, only 3 percent had binged (i.e., had five or mom drinks in a row) in the past 30 days, whereas nearly 40 percent of daily smokers in this age group had binged in the past 30 days (USDHHS 1988). The progression from cigarette smoking and occasional consumption of alcoholic beverages to heavier drinking and illegal drug use does not appear limited to any single Population group. However, there is some evidence that boys with conduct disorders in school and at home may be at especially high risk of progression from any use of tobacco and alcohol to addictive patterns of multiple-drug use. A recent study of 61 males aged 14 through 18 who had conduct disorders found sequawms of acquisitionofdrugusesimilartothosefoundamongadole+ cents in general, but with higher rates of addictive use of the tobaccoalcohol-marijuana cluster and earlier initiation of these substances (Mikulich, Young Gowley 19931. Cigarette Smoking and Other Drug Use Cigarette smoking is neither necessary nor sufficient for other drug abuse or dependence. Not ail cigarette smokers subsequently abuse other drugs, and a small percentage of abusers of alcohol and illegal drue do not use tobacco. However, several studies have revealed that cigarette smoking is a predictor of whether an individual is using other drugs and of what that individual's level of other drug use is. The 1985 NHSDA Health Conse9uencf?s 31 161-235 95-2 Surgeon General's Report (USDHHS 1988; Henningfield, Clayton, Pollin 1990) showed that 12- through 17-year-olds who had smoked cigarettes in the past 30 days were approximately 3 times more likely to have consumed alcohol, 8 times more likely to have smoked marijuana, and 22 times more likely to have used cocaine in the past 30 days than those who had not smoked cigarettes. Data from the 1985- 1989 MTFJ? showed that seniors who had smoked ciga- rettes in the past 30 days were about 1.6 times more likely to have consumed alcohol, 4 times more likely to have smoked marijuana, and 5 times more likely to have used cocaine in the past 30 days than those who had not smoked cigarettes (see "Smoking and Other Drug Use" and Table 23 in Chapter 3). The 1985 NHSDA CUSDHHS 1988; Henningfield, Clayton, Pollin 1990) examined heavier drug use as a function of cigarette smoking. Having 5 or more drinks in succession in the past 30 days, using marijuana on more than 10 occasions, and using cocaine on more than 10 occasions were considered heavier usage of drugs. A strong association was observed between cigarette smok- ing and other drug use among all age groups in this study, although the percentage of the increases in drug use from the never-smoker to the daily-smoker levels was strongest in the 12- through 17-year-old group (Fig- ure 1). Among these youngest smokers, those who smoked daily were approximately 14 times more likely to have binged on alcohol, 114 times more likely to have used marijuana at least 11 times, and 32 times more likely to have used cocaine at least 11 tunes than those who had not smoked. A similar correlation between frequency of alcohol use and level of cigarette smoking was found in a study of 7th- through 12th-grade students in New York State (welte and Barnes 1987). In the Welte and Barnes study, as in the NHSDA, not only were smoking any cigarettes and drinking alcohol related, but daily smoking was a predictor of binge drinking. These data are consistent with those from a study of adult multiple-drug abusers, which found that severity of nicotine dependence, as measured either by a scale that assesses the strength of a given habit or by cigarettes smoked per day, was corre- lated directly with severity of alcohol consumption prob- lems, as measured by scores on the Michigan Alcoholism Screening Test (Kozlowski et al. 1993). These data indi- cate a strong direct relationship between level of nicotine dependence and alcohol abuse but do not in themselves show the direction of the relationship or rule out the possibility that other factors commonly determine the coincidental occurrence of high levels of tobacco and other drug use. Data from a longitudinal study in which 4,192 students (grades six through eight) were surveyed three times over four years extended the findings that the amount of tobacco use is directly related to other drug use (Bailey 1992). Specifically, this study showed that students who during follow-up periods escalated from low-level use of tobacco or alcohol to heavy-1eveI use were more likely to begin using other psychoactive substances .or to increase their use of these substances than students who remained low-level users of tobacco or alcohol (Bailey 1992). Other studies suggest that the age at onset of cigarette smoking determines the probability of subse quent use of marijjana and of heavy alcohol use. For example, Clayton and Ritter (1985) found not only that cigarette smoking, along with alcohol use, was the most powerful predictor of marijuana use, but also that the effect was strongest when smoking was initiated by age 17. Similarly, Keenan (1988) found that the age at onset of cigarette smoking was significantly younger in people with a history of alcoholism than in those who did not use alcohol. Another study estimated that the relative risk of alcoholism was increased tenfold among cigarette smok- ers and that people who heavily use alcohol represent approximately one-third of all cigarette smokers (DiFranza and Guerrera 1990). A further analysis of these and additional data led Kozlowski et al. (1993) to conclude that because the association between smoking and drinking is weaker among light smokers, the per- centage of heavier smokers who develop problems with alcohol might be greater than 30 percent. Of all drug users surveyed by the NIDA, cigarette smokers were by far the most likely to report experienc- ing various features of addiction. Among 12- through 17-year-olds who had used cigarettes, 27 percent were daily users and 20 percent felt dependent; of those who had used alcohol, 6 percent were daily users and 5 per- cent felt dependent; of those who had used marihana, 18 percent were daily users and 10 percent felt dependent; of those who had used cocaine, 14 percent were daily users and 6 percent felt dependent (USDHHS 1988; Henningfield, Clayton, Pollin 1990). Cigarette smoking was also, by far, the drug use most commonly associated with withdrawal symptoms. Thus, cigarette smoking not only occurs early in the progression of drug use, it appears to be the first of these drugs to produce features of addiction in young people. Smoking as a Facilitator for Other Drug Use A number of mechanisms could explain how ciga- rette smoking facilitates the use of alcohol and illegal drugs. These mechanisms are not mutually exclusive. Moreover, other variables may operate to nondifferentially increase the use of tobacco and a wide range of other substances. For example, children with conduct disorders are at increased risk of using tobacco, heroin, alcohol, 32 Health Consequences F,tc,~~~lltjl~S Tobacco use Among YOUfZg PeOpit? fig,,m 1. Use of alcohol mar+a% and cocaine,* by age group, National Household Stuvey on Drug Abuse, 1~ 12-17-year-olds ::- B Alcohol 40 - Marijuana ???? o Cocaine q tJ L 30- 5 y25- `Z ' -2 20- g 15- c lo- .,_l--L 5- never + tried Smoking history 26-34-year-olds 2 35year-olds never tried Smoking history current current 18-25-year-olds 50- 45- 40- p35- `CI po- 5 ~25- `zi 7 2 zo- !i k 15- IO- 5- O-- m Alcohol T, Marijuana * Cocaine never tried Smoking history 45 * Alcohol 2 30 E p 25 `Z 7 E 20 8 b k 15 10 neverf trk?d$ Smoking history current Source: USDHHS (1988). The criteria for current use are as follows: alcohol = drank five or more drinks in a row at least 1 day in the past 30 days; marijuana = used marijuana more than 10 times; cocaine = used cocaine more than 10 times (N = 8,814). values were under 1 for marijuana and cocaine use. * Values were under I for cocaine use. Health Consequences 33 Surgeon General`s Report cocaine, and other drugs WSDHI-IS 1988). SimiIarly, a longitudinal study showed that first-grade children who were characterized by their teachers as either. shy or aggressive were significantly more likely than their peers to smoke cigarettes, drink alcohol, and use illegal drugs in their teenage years (Kellam, Ensminger, Simon 1980). Evidence of other predictive factors, however, does not rule out the possibility that young people who smoke have an increased risk of using other drugs. Morphologic changes in brain structure that have been induced by nicotine exposure might predispose persons to the abuse of other drugs; this mechanism, however, has not yet been experimentally investigated. One possibility is that common pathways of drug- produced reinforcement in the brain might be altered so that the reinforcement produced by subsequent drug exposure is intensified. Central nicotinic receptors are known to be critical mediators of the reinforcing effects of nicotine (USDHHS 1988). In turn, activation of these receptors leads to activation of the dopaminergic reward system, which is critical in mediating the reinforcing effects of a wide variety of abused drugs, including co- caine and heroin. Thus, it is a plausible, but unproven, hypothesis that nicotine exposure would lead to a height- ened sensitivity to the reinforcing effects of other drugs of abuse. This hypothesis is supported by the finding that the development of tolerance to nicotine is accompanied by the development of tolerance ("cross-tolerance") to alcohol (Burch et al. 1988; Collins et al. 1988). Other research with animals also shows that nicotine exposure, eitheraloneorincombinationwithotherdrugs, may alter the behavioral responses to drugs of abuse, including alcohol and cocaine (Signs and Schechter 1986; Horger, Giles, Schenk 19921. These data together suggest a plau- sible biological basis for a causal role for tobacco use in the development of other substance abuse patterns, even if this role is shared by other risk factors. Nicotine produces various effects that have been shown to be produced similarly by one or more other abused drugs; all of these findings were discussed in greater detail in the 1988 Surgeon General's report WSDHHS 1988) and elsewhere (Pomerleau and Pomerleau 1984). Nicotine administration produces feel- ings of pleasure and euphoria that elevate the same scales on the Addiction Research Center Inventory as the effects of heroin, cocaine, alcohol, and other abused drugs (Henningfield, Miyasato, Jasinski 1985; USDHHS 1988). Human subjects report, and laboratory rats demonstrate, that nicotine produces acute effects that are more like a stimulant than a sedative (Henningfield, Miyasato, Jasinski 1985; USDHHS 1988). Nicotine administration causes cortical EEG activation (increase in alpha and beta frequency, decrease in beta power) that is associated with increased vigilance and improved cognitive func- tion (USDHHS 1988; Pickworth, Heming, Henningfield 1989). Conversely, nicotine deprivation leads to EEG deactivation and concomitant decreases in vigilance and cognitive function WSDI-II-IS 1988; Pickworth, Heming, Henningfield 1989). Nicotine administration modulates the various levels of catecholamines, which are impor- tant in the regulation of mood and reactions to stressful stimuli (Pomerleau and Pomerleau 1984; USDHHS 1988). Partly through its effects on serotonergic systems in the brain, nicotine has some of the same effects on appetite as medications prescribed for this purpose. Nico- tine can reduce skeletal muscle tension and thereby con- tribute to the feelings of pleasurable relaxation often attributed to various abused drugs. For all of these drugs, including nicotine, the specific effect produced is related to the dose of the drug administered. Thus, depending on the dose of the drug or drugs taken, the time since the last dose, and other factors, theoretically the user may achieve certain effects with any of several drugs, achieve various maximal effects through drug combinations, or use certain drug combinations in an effort to reduce certain adverse effects (Gardner 1980). Certain trends in drug abuse that have become prominent over the past decade increase the potential role of cigarette smoking in the development of other forms of drug use. SpecificaIly, there are increasing reports of smokable preparations of various drugs, in- cluding cocaine ("crack"), methamphetamine ("ice"), phencyclidine (`TCP"), and heroin, and marijuana con- tinues to be smoked by large numbers of people (USDHHS 1988). Drug administration via smoking re- quires the user to learn to regulate dose and to become tolerant of the rapid onset and aversive effects of smoke inhalation. These basic ski& may be learned through the process of becoming dependent on tobacco, as is dis- cussed in "Developmental Stages of Smoking" in Chap ter 4 of this report and in the 1988 report. Once learned, these skilIs can be transferred to other smoked drugs and can facilitate the process of experimentation with such drugs, as well as increase the potential for addiction. 34 Health Consequences prL77ellting Tobacco Use Among Young People He&h Consequences of Smokeless Tobacco Use Among Ycwng People hmduction Smokeless tobacco includes two main types: chew- ing tobacco and snuff. These products are made from the sln,e type of dark- or burley-leaved tobacco. Most smoke- lt3s tobacco is grown in Kentucky, Pennsylvania, Ten- nessee Virginia, West Virginia, and Wisconsin. Leaves ,,re generally aged one to three years, but snuff tobacco leaves are aged longer than chewing tobacco leaves (Shapiro 1981). People who use chewing tobacco place a l,.J of loose-leaf tobacco or a plug of compressed tobacco in their cheek; snuff users place a small amount `,f powdered or finely cut tobacco (loose or wrapped in a paper pouch) between their gum and cheek (USDHHS 1992b). Smokeless tobacco users then suck on the to- bacco and spit out the tobacco juices with accompanying saliva. As a consequence of the way in which smokeless products are used, smokeless tobacco is sometimes re- icrred to as spit or spitting tobacco (USDHHS 1992b). The most notable health consequences associated with smokeless tobacco use include halitosis (bad breath), discoloration of teeth and fillings, abrasion of teeth, den- tal caries, gum recession, leukoplakia, nicotine depen- dence, and various forms of oral cancer (USDHHS 1986b, 1992a; WHO 1988). SpecificaIly, smokeless tobacco use has been implicated in cancers of the gum, mouth, phar-. ynx, larynx, and esophagus (USDI-IHS 1986b; Winn 1988) and has also been indicated in early reports of the devel- opment of verrucous carcinoma (winn 1988). Smokeless tobacco use may also play a roie in cardiovascular dis- ease and stroke, through increases in blood pressure, vasoconstriction, and irregular heartbeat (Hsu et al. 1980; Gritz et al. 1981; !Schroeder and Chen 1985). Since nearly 25 percent of adult smokeless tobacco users also smoke cigarettes (CDC 1993131, the effects on the oral cavity may be synergistic, and the risks of developing cancer of the oral cavity and pharynx noticeably increase (Blum 1980). Epidemiologic Evidence The 1986 Surgeon General's report on smokeless tobacco use concluded that there is no safe use of tobacco. Despite that report and subsequent legislation, restric- tions, and follow-up reports (USDHHS 1992a, b; see "Warning Labels on Tobacco Products" in Chapter 6 and "Smokeless Tobacco Advertising and Promotional Ex- penditures" in Chapter 51, smokeless tobacco use in the United States remains a serious concern. The use of smokeless tobacco by adults has remained relatively con- stant at about 5 percent for males and 1 percent for females. However, smokeless tobacco use among high school males has become markedly more prevalent in the past two decades; about 20 percent report using smoke- less tobacco in the past month (see "Current Use of Smokeless Tobacco" in Chapter 3 for documentation and further discussion of the prevalence of smokeless tobacco use). In some states, nearly one out of three high school males uses smokeless tobacco. There is little indication that use among young people is significantly declining (Glover et al. 1988; Boyd and Clover 1989; USDHHS 1992b; see "Current Use of Smokeless Tobacco" in Chapter 3). Smokeless tobacco use primarily begins in early ado- lescence; some research indicates an average age of onset of 10 years (USDHHS 1992b). Among high school seniors who had regularly used smokeless tobacco, 23 percent reported that they had first tried the product by the sixth grade, and 53 percent by the eighth grade (see "Grade When Smokeless Tobacco Use Begins" in Chapter 3). Health Consequences A recent report of the Office of Inspector General (LJSDI-IHS 1992b) concluded that smokeless tobacco use causes serious, but generally not fatal, short-term health consequences among young people. The primary health consequences during adolescence include leukoplakia, gum recession, nicotine addiction, and increased risk of becoming a cigarette smoker. Leukoplakia and/or gum recession occur in 40 to 60 percent of smokeless tobacco users (USDHHS 1992b). Leukoplakia has been defined by the World Health Organization as a lesion of the soft tissue that consists of a white patch (mucosal macule) or plaque that cannot be scraped off (Kramer et al. 1978; Axell et al. 1984). Greer and Poulson (1983) examined 117 high school students who were smokeless tobacco users; oral soft-tissue le- sions were found in 49 percent of these students. Oral leukoplakias carry a five-year malignant transformation potential of about 5 percent (pindborg 1980,1985; Bouquot 1987, 1991). If smokeless tobacco use ceases, the leukoplakia appears to regress or resolve entirely (Chris- ten, McDonald, Christen 1991). Gingival tissue recession (or gum recession) com- monly occurs in the area of the oral cavity immediately adjacent to where smokeless tobacco is held. When smokeless tobacco remains exclusively in a specific intraoral location, gingival recession occurs among 30 percent (Weintraub et al. 1990) to over 90 percent (Schroeder et al. 1988) of users. Mock&r, Lavstedt, and Ahlund (1980) found that snuff use among 13- and Health Consequences 35 Surgeon General's Report 14-year-old students could directly affect the gingival tissues, causing gingivitis, or gum inflammation. In a study of 565 adolescent male students with gingivitis in Georgia, Offenbacher and Weathers (1985) found that gingival recession was significantly more prevalent, and the odds of developing this condition were nine times greater, among smokeless tobacco users than among nonusers. Navy recruits from 45 states were examined to determine if smokeless tobacco use was associated with gingival recession (Weintraub et al. 1990). Results of the study showed that 31 percent of heavy users and 19 percent of nonusers or low users had gingival recession. Users' age and the intensity of smokeless tobacco use were significant factors in ex- plaining variations in the degree of gingival recession. Two additional studies of adolescents failed to show an association between the use of smokeless tobacco and gingival recession (Wolfe and Carlos 1987; Creath et al. 1988), possibly because most of the users had been using the product for a short time. Nicotine Addiction The addictive qualities of smokeless tobacco are also a matter of major concern (Christen and Glover 1981; Glover, Christen, Henderson 1981; Glover et al. 1989; Hatsukami, Nelson, Jensen 1991). Smokeless tobaccousers develop a nicotine dependency similar to that of cigarette smokers (Benowitz et al. 1988). This is not surprising, since smokeless tobacco users absorb at least as much nicotine as smokers do (Russell, Jarvis, Feyerabend 198O&perhaps as much as twice the amount (Benowitz et al. 1.988). The high pH of saliva favors absorption of nicotine through oral mucosa, and the degree of absorption increases with the increasing pH of the tobacco product. The rate of absorp- tion of nicotine from snuff is particularly rapid (Russell, Jarvis, Feyerabend 1980; Edwards, Glover, Schroeder 1987). With continued use of smokeless tobacco, blood nicotine levels remain relatively high; these levels fall more slowly after smokeless tobacco is removed from the mouth than after a cigarette has been smoked (Benowitz et al. 1988). Adolescents develop physical dependence from smokeless tobacco use, as is evidenced by their experi- ence of withdrawal symptoms when they try to quit (see "Smokeless Tobacco Cessation" in Chapter 6). Smokeless tobacco cessation produces withdrawal symptoms that are similar to those for smoking cessa- tion (Hatsukami, Gust, Keenan 1987), including cravings, irritability, distractibility, and hunger. Adolescents who are most addicted to nicotine appear to be less able to quit (Eakin, Severson, Glasgow 1989). Thus, as is seen with cigarette use (see "Adult Implications of Adoles- cent Smoking" in Chapter 3 and "Adolescent Smoking Behavior as a Risk Factor for Subsequent Smoking" in Chapter 4), adolescents who are heavy smokeless to- bacco users are likely to become adult users. The addictive potential of smokeless tobacco use is aggravated by the fact that some smokeless products are highly effective in the initiation process and are even termed "starter products" by one smokeless tobacco com- pany (Marsee v. United States Tobacco Company 1989; Henningfield and Nemeth-Coslett 1988). These prod- ucts tend to be low in nicotine concentration and low in pH (thus reducing absorption); some are in a unit dosage form ("tobacco pouch"), which helps first-time users avoid placing too much of the substance in their mouths. These products may have contributed to the reversal of the demographics of smokeless tobacco users from 1970 to 1986. In 1970, the majority of smokeless tobacco users were 50 years old and older; by 1986, the majority were 35 years old and younger (USDHHS 1987,198s). As is discussed in Chapter 5 (see "Smokeless Tobacco Adver- tising and Promotional Expenditures"), marketing and advertising factors have been identified as having in- stilled the general perception that smokeless tobacco products are safe and socially acceptable (Connolly et al. 1986; USDHHS 1987; Glover et al. 1989). Marketing strategies included a heavy reliance on distributing free samples of product types designed to introduce new users to what one company termed the "graduation process" (Marsee v. United States Tobacco Company 1989). Advertising strategies then encouraged new users to experience greater "satisfaction" and "pleasure" by switching to maintenance products higher in nicotine concentration and pH (Marsee v. United States Tobacco Company 1989; Henningfield and Nemeth-Coslett 1988). Smokeless Tobacco Use as a Risk Factor for Cigarette Smoking Young people who use smokeless tobacco appear to be at greater risk to smoke cigarettes than are nonus- ers. Among smokeless tobacco users, 12 to 43 percent also smoke cigarettes @kin, Severson, Glasgow 1989; Williams 1992; CDC 1993b; Stevens et al., in press; see Table 23 in Chapter 3). In the 1986-1989 MTFI', 44 percent of high school seniors had tried both smokeless tobacco and cigarettes; of those, 63 percent had tried smokeless tobacco either before or at about the same time as cigarettes (see Table 38 in Chapter 3). In a prospective study, Ary, Lichtenstein, and Severson (1987) found that smokeless tobacco users were significantly more likely than nonusers to initiate cigarette smoking. Smokeless tobacco users were also more likely to increase their use of cigarettes over a one-year period. For adolescents who use both smokeless tobacco and cigarettes, cessation of one substance may lead to a direct increase in the other (Biglan, La Chance, Benowitz, unpublished data). 36 Health Consequences ;`,.lv~~Lvltjlls Tobacco Use AIIIO~I~ Young People smokeless Tobacco Use as a Risk Factor for Other Drug Use Smokeless tobacco use is also predictive of other Linlg use. In a study of more than 3,ooO male adolescents intcnie~ved twice at nine-month intervals about their use ,,i \.arious psychoactive substances (Ary, Lichtenstein, +!.er;on 1987), the main findings were that (1) smokeless tc,bacco users were significantly more likely to use ciga- rcttc5, marijuana, or alcohol than nonusers, (2) users of .Ir,&eless tobacco were significantly more Likely to take L1F7 the use of these other substances by the second inter- \.,~`Iv if they were not using them at the first, and (3) ,l&¢s who were using any of these substances at the ConclLlsions first interview were significantly more likely to increase their use of the substance if they also used smokeless tobacco. Two other facts are important to consider when evaluating the role of smokeless tobacco products in the use of cigarettes and other substances. Fist, the overall impact of smokeless tobacco is currently limited prima- rily to males (the main users of these substances) (LJSDHHS 1986b, 1990). Second, smokeless tobacco users in the Ary, Lichtenstein, and Severson (1987) study, as well as in most other surveys, tend to initiate their tobacco use at about the same age as cigarette smokers or at a slightly earlier age (see "Grade When Use of Smoke- less Tobacco and Cigarettes Begins" in Chapter 3). Cigarette smoking during childhood and adoles- cence produces significant health problems among young people, including cough and phlegm pro- duction, an increased number and severity of respi- ratory illnesses, decreased physical fitness, an unfavorable lipid profile, and potential retardation in the rate of lung growth and the level of maximum lung function. 7 ^. Among addictive behaviors, cigarette smoking is the one most likely to become established during ado- lescence. People who begin to smoke at an early age are more likely to develop severe levels of nicotine addiction than those who start at a later age. 3. Tobacco use is associated with alcohol and illicit drug use and is generally the first drug used by young people who enter a sequence of drug use that can include tobacco, alcohol, marijuana, and harder drugs. 4. Smokeless tobacco use by adolescents is associated with early indicators of periodontal degeneration and with lesions in the oral soft tissue. Adolescent smokeless tobacco users are more likely than nonus- ers to become cigarette smokers. Health Consequences 37 prewnting Tobacco Use Among Young People Chapter 3: Epidemiology of Tobacco Use Among Young People in the United States Introduction Understanding national trends and patterns of to- bacco use among adolescents is crucial to the public health effort to reduce. tobacco-related morbidity and mortality. Along with information on young people's knowledge, attitudes, and perceptions concerning to- bacco use, these data can help elucidate historical pat- terns, suggest target groups for programs to prevent tobacco use, determine the need for future interventions, assess the effect of national campaigns against tobacco use, and contribute to predictions of the future burden of tobacco-related disease. Previous reports from the Surgeon General have described tobacco use among the nation's youth (US. Department of Health, Education, and Welfare [USDHEWI 1979a; U.S. Department of Health and Hu- man Services [USDHHSI 1989b). The following analysis both updates and expands these discussions. In particu- lar, the analysis incorporates cross-sectional data from four national surveillance systems that track health be haviors (including tobacco use) among adolescents and from one-adult survey with information on older adoles- cents (Table 1). Data are also used from a national longitudinal survey of adolescents and young adults. The National Teenage Tobacco Surveys (NTTS) cited in this chapter were conducted by the U.S. Public Health Service and the U.S. Department of Education in 1968, 1970,1972, 1974, and 1979; a modified version of the survey was conducted in 1989 as the Teenage Atti- tudes and Practices Survey (TAPS). The National House- hold Surveys on Drug Abuse (NHSDA) cited were conducted nine times from 1974 through 1991 by the National Institute on Drug Abuse (NIDA); the survey is now sponsored by the Substance Abuse and Mental Health Services Administration (SAMHSA). The Moni- toring the Future Project (MTFP) surveys included were conducted yearly from 1976 through 1992 for NIDA by the University of Michigan's Institute for Social Research (ISR). The Youth Risk Behavior Survey (YRBS), cited extensively throughout this chapter, was conducted in 1991 by the Centers for Disease Control (CDC) as a component of the Youth Risk Behavior Surveillance System. The National Health Interview Surveys (NHIS) cited in this report included yearly data on cigarette smoking during 11 years from 1970 through 1991. Sur- vey methodology varied across these surveillance sys- tems (see Appendix 1, "Sources of Data," for more detail on methodologic characteristics), and the different sur- veys offered several measures of tobacco use (see Ap- pendix 2, "Measures of Ciga,,rette Smoking," and Appendix 3, "Measures of Smokeless Tobacco Use"). The most comparable of these data sources are TAPS, the NHSDA, the MTFP, and the YRBS. Because the questions used, the ages sampled, and the sites and modes of administration (school-based self-administered questionnaires vs. household-based telephone and in- person interviews) differ, however, even these data are not directly comparable. The MTFP, for example, consis- tently reports higher prevalence estimates than the two household surveys, mainly because the study popula- tion is limited to high school seniors; these respondents, who are usually 17 or 18 years old, are considerably older than the 12- through IS-year-old population included in TAPS and the NHSDA. When possible, most of the comparisons presented in this chapter in- clude age- or. grade-specific estimates. However, even after controlling for age differences, the estimates on some measures of tobacco use from the household sur- veys are lower than the estimates from the school sur- veys (see Appendix 2). The purpose of this chapter is to document re- ported trends and patterns of tobacco use in one source. Differences in the age of the target populations employed, in the setting of the survey, in the wording of questions, and in other factors may cause apparent differences in the actual values of some of the estimates reported here. However, these difference are frequently resolved when methodological issues are taken into consideration. In- corporating data from several types of data collection systems has revealed a number of consistencies in pat- terns and trends of tobacco-use behaviors that apply to both school-based and household-based sample frames (and thus to school attenders, infrequent school attenders, and dropouts). Epidemiology 39 Surgeon General's Rep-t Table 1. Sources of national data on tobacco use among young people, 1968-1992 Survey title Abbreviated title Sponsoring agency Type of or organization survey Years National Household NHSDA Surveys on Drug Abuse National Institute on Drug Abuse/ Substance Abuse and Mental Health Services Administration Cross-sectional 1974,1976,1977, 1979,1982,1985, 1988,1990,1991 Youth Risk Behavior YRBS Division of Adolescent Cross-sectional 1991 Survey and School Health, (national, as CDC well as state and local) Sources: NITS: U.S. Department of Health, Education, and Welfare (1972,1976,1979b); TAPS: CDC (1991a); Allen et al. (1991,1993); Moss et al. (1992 1; NHSDA: Abelson and Atkinson (19751; Abelson and Fishbume (1976); Fishbume, Ableson, Cisin (1980); Gfroerer (1993); Miller et al. (1983); U.S. Department of Health and Human Services [USDHHSJ (1988a, 1990a, 1991a, 1992a, 1993); 1991 NHSDA: CDC, OSH (unpublished data); MTFP: Bachman, Johnston, O'Malley (198Oa, b, 1981,1984, 1985,1987,19911; Johnston, Bachman, O'Malley (198Oa, b, 1982,1984,1986,1991,1992); Johnston, O'Malley, Bachman (1991a, b, 1992a, b, in press); 1990-1992 MTFP surveys: Institute for Social Research, University of Michigan (unpublished data); YRBS: Kolbe (1990); CDC (1992c, d); Kolbe, Kann, Collins 1993; CDC, Division of Adolescent and School Health (unpublished data); NHIS: NCHS (1958,1975,1985,1988a, b, 1989); USDHHS (1992a); 1970,1978-1980,1987-1988 NHIS: CDC, GSH (unpub- lished data). "The 1989 TAPS was partially sponsored by the American Cancer Society. 40 Epidemiology f%venting Tobacco Use Among Young People Mode of survey Response Ages/ Sample administration rate grades size Type of tobacco use examined Household interview Mean of approximately 80%; 84% in 1991 17-19 years (trend data); 12-18 years (1991 analysis); 30-39 years (retrospective 1991 analysis) 371-3,429 9,086 6,388 Smoking: all years Smokeless: 1988 -1991 Self-administered in school For national survey: 9th-12th grades 12,272 in Smoking and 90% of sampled stu- national smokeless dents; 75% of selected survey schools The Institute for Social Research usually reports the N (weighted), which is approximately equal to the sample size. Cases are weighted to account for differential probability of selection and then normalized to average 1.0. The range for N (weighted) for questions on smokeless tobacco between 1986 and 1992 = 2,553 -2,991. `N (weighted) for smokeless tobacco = 7,093. "N (weighted) for smokeless tobacco = 8,441. Epidemiology 41 Surgeon GeneraI's Report Cigarette Smoking Among Young People in the United States Recent Patterns of Cigarette Smoking Ever Smoking The proportion of, adolescents classified as ever smokers (i.e., those who had tried a cigarette [see Appen- dix 2 for variations in this measure]) varied across sur- vey systems (Table 2). In the 1989 TAPS, 47 percent of students aged 12 through 18 had tried smoking. In the 1991 NHSDA, the prevalence for this same age range was 42 percent. The different estimates between these two household surveys may reflect actual decreased prevalence during the intervening two years or may result from sampling error, from slight differences in response to different survey questions, or from the dif- ferent way these home-based surveys were adminis- tered (by telephone in TAPS and in person in the NHSDA). Of the two self-administered school surveys, the 1991 YRBS reported a higher prevalence of ever smoking (70 percent) than the 1992 MTFP (62 percent), even though the YRBS included students in grades 9 through 12 (age range generally 14 through 18 years), whereas the MTFP was limited to high school seniors. This difference may partly result from the questions each survey used to elicit information on ever smoking. The MTFP survey asked, "Have you ever smoked cigarettes?", and the YRBS asked a question that might have drawn additional affirmative responses: "Have you ever tried or experimented with cigarette smoking, even one or two puffs?" What stands out from all four surveys is that by age 18, about two-thirds of adolescents in the United States have tried smoking. Also evident across the sur- veys is that the prevalence of ever smoking is greater (if only slightly so in one survey) among males than fe- males. Findings by racial/ethnic groups were generally in accord across the surveys: whites had the highest prevalence of ever smoking and blacks the lowest in TAPS, the NHSDA, and the MTFP; Hispanics had the highest prevalence of the three groups in the YRBS. Ever smoking increased as a function of increasing age or grade in all four surveys. Adolescents living in the north-central region of the United States were the most likely to report having smoked (Table 2). Prevalence for individual states were available from the Youth Risk Behavior Surveillance System, which besides its yearly national YRBS also conducts individual surveys in se- lected states and cities. In 1991, the percentage of stu- dents who had tried smoking ranged from 49 to 82 percent (median, 71 percent) (Table 3). 42 Epidemiology Current Smoking The overall national prevalence of current smoking (i.e., having smoked within the last 30 days) for persons 12 through 18 years old was estimated to be 16 percent in the 1989 TAPS and 13 percent in the 1991 NHSDA (Table 4). These estimates suggest that at least 3.1 million U.S. adolescents are current smokers. Among high school seniors, the prevalence of past-month smoking was 28 percent in the 1992 MTFP; 28 percent of high school students were past-month smokers in the 1991 YRBS. In all the surveys, current prevalence among males was equal to or slightly higher than current prevalence for females. This pattern differs from that reported for the late 1970s and mid-1980s, when the prevalence for adolescent females was generally higher than that for adolescent males (USDHEW 1979b; USDHHS 1989b). The national prevalence of past-month smoking among adolescents was higher for whites than for His- panics and was lowest for blacks (Table 4). Pooled data from the 1985-1989 MTFP provided information on smok- ing among Asian American and Native American ado- lescents (Bachman et al. 1991). Past-month smoking prevalence was higher for Native American male (37 percent) and female (44 percent) seniors than for white male (30 percent) and female (34 percent) seniors. Cur- rent smoking was about as common for Asian American male (17 percent) and female (14 percent) seniors as it was for black male (16 percent) and female (13 percent) seniors. Data on Hispanic smoking prevalence, pre- sented in the same report, indicate that smoking preva- lence among Hispanic high school seniors from 1985 through 1989 ranked between that of white and black high school seniors, as it did in TAPS, the NHSDA, and the YRBS. Current prevalence increased with increasing age or grade (Table 4). TAPS and the NHSDA reported smoking prevalences for persons 17 and 18 years old that were slightly lower than those of 12thgrade students surveyed by the MTFP and the YRBS. Prevalence esti- mates from TAPS and the NHSDA for persons 15 and 16 years old were considerably lower than for 9th- and 10th~grade high school students in the MTFP and the YRBS. These estimates are consistent with the argument that estimates of cigarette smoking from household sur- veys may underreport actual use, especially for younger adolescents. pr,yvrltitlg Tobacco Use Among Yozrng People Table 2. Percentage of young people who have ever smoked cigarettes, by gender, race/Hispanic origin, age/grade, and region, Teenage Attitudes and Practices Survey (TAPS), National Household Surveys on Drug Abuse (NHSDA), Monitoring the Future Project (MTFP), Youth Risk Behavior Survey (YRBS), United States, 1989,1991,1992 Characteristic 1989 1991 TAPS NHSDA+ 1992 MTFPg_ 1991 YRBS 44.5 41.9 61.8 70.1 Overall Gender Male Female 48.3 44.4 63.5 70.6 44.4 39.3 60.2 69.5 Race/Hispanic origin \Vhite, non-Hispanic Male Female Black, non-Hispanic Male Female Hispanic Male Female 49.5 46.5 51.5 49.1 49.3 43.7 36.4 28.1 38.7 31.0 34.1 25.0 43.1 34.4 42.5 36.1 43.7 32.5 65.3 66.2 64.6 42.6 45.5 40.4 NA'1 70.4 71.4 69.3 67.2 64.7 69.3 75.3 75.7 74.9 Age/grade 12-14 years 15-l 6 years 17-18 years 8th grade 9th grade 10th grade 11 th grade 12th grade 29.7 26.0 52.5 45.9 63.9 60.9 45.2 64.8 68.3 72.8 74.5 53.5 61.8 Region Northeast North Central South West 46.0 39.7 63.7 70.6 47.9 46.2 65.2 73.0 46.5 41.1 61.1 71.3 45.0 40.3 56.5 65.0 Sources: 1989 TAPS: Centers for Disease Control and Prevention (CDC), Office on Smoking and Health (OSH) (unpublished data); 1991 NHSDA: CDC, OSH (unpublished data); 1992 MTFP: Johnston, O'Malley, Bachman (in press); Institute for Social Research, University of Michigan (unpublished data); 1991 YRBS: CDC (19%~); CDC, Division of Adolescent and School Health (unpublished data). `1989 TARS, aged 12-18 years. Based on responses to the questions, "Have you ever smoked a cigarette?" and "Have you ever tried or experimented with cigarette smoking, even a few puffs. 7" Respondents who had smoked a cigarette, even a few puffs, were classified as ever smokers. `1991 NHDSA, aged 12-18 years. Based on response to the question, "About how old were you when you first tried a cigarette?" ("Never tried a cigarette" was a preceded response.) `1992 MTFP survey. Based on response to the question, "Have you ever smoked cigarettes ?I' they had tried cigarettes at least once or twice were classified as ever smokers. Respondents who reported that `With the exception of data for 8th and IOth-grade students, all other data points for the MTFP survey reflect estimates for high school seniors. `1991 YRBS, grades 9-12. Based on response to the question, `NA = Not available. "Have you ever tried cigarette smoking, even one or two puffs?' Epidemiology 43 Surgeon General's Report Table 3. Percentage of high school students who use cigarettes, by gender, Youth Risk Behavior Surveys, United States and selected U.S. sites, 1991 Site Lifetime cigarette use* Current cigarette use+ Frequent cigarette use* Female Male Total Female Male Total Female Male Total Weighted data National survey State surveys Alabama Georgia Idaho Nebraska New Mexico New York5 Puerto Rico3 South Carolina South Dakota Utah Local surveys Chicago Dallas Fort Lauderdale EirViCitY Philadelphia San Diego Unweighted dataq State surveys Colorado_ District of Columbia3 Hawaii Montana New Hampshire New Jerseys Oregon Pennsylvania5 Tennessee Wisconsin Wyoming Local surveys Boston New York City San Francisco 70 71 70 27 28 28 12 13 13 70 79 74 24 32 28 11 16 13 66 72 69 22 26 24 10 12 11 56 65 61 22 24 23 12 14 13 70 75 72 28 30 29 15 15 15 82 81 82 30 30 30 13 14 13 72 70 71 32 28 30 18 17 17 46 54 50 13 18 16 3 5 4 72 76 74 25 26 26 13 13 13 68 71 69 32 30 31 17 16 16 43 55 49 16 18 17 8 8 8 72 73 72 13 20 16 4 7 6 70 76 73 11 16 14 4 4 4 65 65 65 18 13 16 10 6 8 73 70 72 17 16 16 4 4 4 66 66 66 12 17 15 4 8 6 82 70 76 22 17 20 11 8 10 64 71 68 18 18 18 7 7 7 73 74 74 28 27 27 13 14 14 70 60 65 5 7 6 2 2 2 70 70 70 27 25 26 12 13 13 68 71 69 24 24 24 13 12 12 71 71 71 28 27 27 16 15 15 67 61 64 NA*+ NA NA NA NA NA 63 65 64 22 22 22 9 10 9 69 73 71 28 28 28 16 15 15 72 75 74 30 30 30 16 16 16 72 73 73 30 32 31 16 17 16 70 74 72 27 28 28 15 17 16 68 68 68 15 16 15 6 9 7 76 68 72 26 16 21 12 6 9 61 63 62 14 15 14 7 6 6 Source: Centers for Disease Control (19926). *Ever tried cigarette smoking, even one or two puffs. `Smoked cigarettes on 1 or more of the 30 days preceding the survey. `Smoked cigarettes on 20 or more of the 30 days preceding the survey. Surveys did not include students from the largest city. Categorized as a state for funding purposes. `Fourteen sites had overall response rates below 60% or had unavailable documentation; weighted estimates were not reported. **NA = Not available. 44 Epidemiology Table 4. Percentage of young people who currently smoke cigarettes (within the past 30 days), by gender, race/Hispanic origin, age/grade, and region, Teenage Attitudes and Practices Survey (TAPS), National Household Surveys on Drug Abuse (NHSDA), Monitoring the Future Project (MTFP), Youth Risk Behavior Survey (YRBS), United States, 1989,199X 1992 characteristic 1989 1991 1992 1991 TAPS" NHSDA+ MTFPu YRBS' &wall Gmkr \lale Female ;(Jc~/ Hispanic origin IVhite, non-Hispanic Male Female Black, non-Hispanic Male Female Hispanic Male Female Age/grade 12-14 years 15-16 years 17-l 8 years 8th grade 9th grade 10th grade 11 th grade 12th grade Region Northeast North Central South West 15.7 13.1 27.8 27.5 16.0 13.5 29.2 27.6 15.3 12.8 26.1 27.3 18.5 15.4 18.7 15.5 18.2 15.3 6.1 5.3 7.8 6.0 4.9 4.6 11.8 10.1 11.8 9.5 11.7 10.8 5.9 3.9 17.5 14.0 27.5 25.5 17.6 14.7 29.6 23.7 16.6 14.9 31.7 36.5 14.0 11.7 26.4 24.8 15.5 12.3 22.8 23.1 31.8 32.1 31.5 8.2 10.8 5.8 NA' 15.5 21.5 27.8 30.9 30.2 31.7 12.6 14.1 11.3 25.3 27.8 22.9 23.2 25.2 31.6 30.6 Sources: 1989 TAPS: Centers for Disease Control and Prevention (CDC), Office on Smoking and Health (OSH) (unpublished data); 1991 NHSDA: CDC, OSH (unpublished data); 1992 MTFP: Johnston, O'Malley, Bachman (in press); Institute for Social Research, University of Michigan (unpublished data); 1991 YRBS: CDC (1992~); CDC, Division of Adolescent and School Health (unpublished data). $1989 TAPS, aged 12-18 years. Based on responses to the questions, "Have you ever smoked a cigarette?" and "Think about the last 30 days. On how many of these days did you smoke?" `1991 NHSDA, aged 12-18 years. Based on response to the question, "When was the most recent time you smoked a cigarette?" `I992 MTFP survey. Based on response to the question, "How frequently have you smoked cigarettes during the last 30 days?" `With the exception of data for 8th- and IOth-grade students, all other data points for the MTFP survey reflect estimates for high school seniors. `1991 YRBS, grades 9-12. Based on response to the question, "During the past 30 days, on how many days did you smoke cigarettes?" `NA = Not available. Epidemiology 45 Surgeon Ceneral*s Report Past-month smoking was generally most common in the north-central region of the United States and least prevalent in the West and the South (Table 4). Among the available state and local surveys of high school stu- dents (Table 31, the percentage of students who were current smokers ranged from 6 to 31 percent (median 27 percent>. From the weighted surveys, current smoking prevalence was lowest in Puerto Rico and Utah and highest in South Dakota, New Mexico, and New York (excluding New York City). Frequent and Heavy Smoking In the 1989 TAPS, 8 percent of U.S. adolescents 12 through 18 years old were frequent smokers (i.e., had smoked on 20 or more of the 30 days preceding the survey) (Table 5). In 1991, 13 percent of high school students surveyed in the YRBS were frequent smokers. In the 1991 NHSDA, 7 percent of persons 12 through 18 years old were heavy smokers (i.e., had smoked at least one-half pack per day); 10 percent of high school seniors in the 1992 MTFP survey were heavy smokers. Males were slightly more likely than females to report frequent or heavy smoking (Table 5). To a greater extent than was found for current smoking, white adolescents were more likely than black or Hispanic adolescents to be frequent or heavy smokers. Among white adolescents in the different surveys, fre- quent and heavy smoking were 2.8 to 7.5 times m&e common than among black adolescents and 2.3 to 2.6 times more common than among Hispanic adolescents. As was noted for both ever smoking and current smoking, frequent and heavy smoking increased with increasing age or grade. Frequent and heavy smoking were more prevalent in the north-central and northeast regions and less prevalent in the South and the West. Sociodemographic Risk Factors for Smoking In its surveys of high school seniors from 1985 through 1989, the MTFP elicited data on several possible so&demographic risk factors for adolescent smoking (Table 6). The surveys found, for example, that students who lived alone had the highest prevalences of past- month smoking (47 percent) and heavy smoking (28 percent). Living in a single-parent household increased the risk of past-month or heavy smoking only when the mother was the absent parent. Data from the 1968,1970, 1972, 1974, and 1979 NTE indicate higher smoking prevalences among youth living in households with fewer than two parents or parent surrogates KJSDHEW 1972, 1976,1979b). The available published reports, however, did not provide more detail on the exact structure of the household. The 1989 TAPS examined other aspects of family structure for possible associations with adolescent smok- ing status (Allen et al. 1993). The survey findings showed that youths 12 through 16 years old who were current smokers were-almost twice as likely to be home without a parent or other adult for 10 or more hours a week than were teens who had never smoked. Furthermore, TAPS teens who said that they discussed serious problems with friends rather than with a parent, other relative, or another adult were two times more likely to be current smokers than were teens who reported discussing seri- ous problems with their parents (Moss et al. 1992). The 1985-1989 MTFP reported an inverse relation- ship between both past-month and heavy smoking and the population density of the locales in which the seniors grew up (Table 6); those seniors who grew up on a farm or in the country were more likely to smoke than those who grew up in large cities. The MTFP also found that as school performance among high school seniors declined from above average to below average, past-month smok- ing prevalence increased from 22 to 41 percent, and heavy smoking prevalence increased from 7 to 21 per- cent. A similar relationship was observed in the 1989 TAPS (Moss et al. 1992). Postgraduation plans were another predictor of smoking behavior among MTFP seniors. Students who said they planned to complete four years of college were less likely to be past-month smokers (24 percent) or heavy smokers (7 percent) than were those who did not plan to get a college degree (39 percent were past-month smokers, 20 percent were heavy smokers). Males who planned to enter the armed forces after high school were more likely to be past-month smokers (31 percent) or heavy smokers 04 percent) than males who did not have such plans (26 percent were past-month smokers, 10 percent were heavy smokers). This association was neg- ligible among females. Among MTFP seniors, past-month and heavy smoking were least prevalent among those who felt that religion was very important in their lives and increased uniformly as the self-reported importance of religion lessened. Similarly, adolescent smokers in the 1989 TAPS were more likely to report that they rarely or never attended religious services (54 percent) than were never smokers (29 percent) (Amen et al. 19%). TAPS also analyzed smoking by dropout status. Respondents who had left school before graduating were more than twice as likely to report smoking in the past week as were those who currently attended or had gradu- ated from high school (43 vs. 17 percent) (CDC 1991a). Female high school students and graduates were about as likely as their male counterparts to have smoked in the past week (17 vs. 18 percent). Female dropouts, however, % Epidemiology pr`verrtitjg Tobacco Use Among Young People Table 5. Percentage of young people who report frequent or heavy use of cigarettes, by gender, race/ Hispanic origin, age/grade, and region, Teenage Attitudes and Practices Survey (TAPS), National Household Surveys on Drug Abuse (NHSDA), Monitoring the Future Project (MTFP), Youth Risk Behavior Survey (YRBS), United States, 1989,1991,1992 Characteristic 1989 1991 TAPS* NHSDA' 1992 MTFPt,_ 1991 YRBS3 Measure of use Overall Gender Male Female Race/Hispanic origin White, non-Hispanic Male Female Black, non-Hispanic Male Female Hispanic Male Female Age/grade 12-14 years 15-l 6 years 17-18 years 8th grade 9th grade 10th grade 11 th grade 12th grade Region Northeast North Central South West Frequent Heavy Heavy Frequent 8.1 6.6 10.0 12.7 8.4 6.9 10.4 13.0 7.7 6.2 9.2 12.4 10.1 7.9 10.5 8.1 9.7 7.6 1.9 2.8 2.8 3.7 1.0 1.8 4.4 3.0 4.0 2.4 4.9 3.6 1.8 1.2 8.3 6.5 16.7 14.4 8.7 7.7 11.1 12.1 9.1 7.1 10.9 18.9 7.3 6.2 10.2 10.5 7.6 5.7 6.8 9.0 12.0 12.2 11.6 1.6 2.4 0.9 NAP 2.9 6.0 10.0 15.4 15.0 15.8 3.1 4.5 1.9 6.8 8.0 5.7 8.4 11.3 15.6 15.6 Sources: 1989 TAPS: Centers for Disease Control and Prevention (CDC), Office on Smoking and Health (OSH) (unpub- lished data); 1991 NHSDA: CDC, OSH (unpublished data); 1992 MTFP: Johnston, O'Malley, Bachman (in press); Institute for Social Research, University of Michigan (unpublished data); 1991 YRBS: CDC (1992~); CDC, Division of Adolescent and School Health (unpublished data). *1989 TAPS, aged 12-18 years. Based on responses to the questions, "Have you ever smoked a cigarette?" and "Think about the last 30 days. On how many of these days did you smoke. 7" Those who had smoked on 20 or more of the previous 30 days were classified as frequent smokers. `1991 NHSDA, aged 12-18 years. Based on response to the question, "How many cigarettes have you smoked per day, on the average, during the past 30 days ?" Respondents who reported smoking about one-half pack a day (6-15 cigarettes) or more were classified as heavy smokers. $1992 MTFP survey. Based on response to the question, "How frequently have you smoked cigarettes during the last 30 days?" Respondents who reported smoking about one-half pack per day or more were classified as heavy smokers. _With the exception of data for 8th- and IOth-grade students, all other data points for the MTFP survey reflect estimates for high school seniors. `1991 YRBS, grades 9-12. Based on response to the question, "During the past 30 days, on how many days did you smoke cigarettes?" Those who had smoked on 20 or more of the previous 30 days were classified as frequent smokers. `NA = Not available. Epidemiology 47 Surgeon General's Report Table 6. Prevalence (%I of cigarette smoking among high school seniors, by various sociodemographic risk factors, Monitoring the Future Project, United States, 1985-1989 Sociodemographic risk factor N (weighted) Smoked during past month Smoked 2 10 cigarettes/day Household structure Lives with both parents Lives with father only Lives with mother only Lives alone Other 58,100 28.3 10.3 2,657 35.4 16.3 13,955 29.5 12.2 547 47.2 28.3 5,783 34.4 17.8 Population density of locale in which respondent grew up Farm Country Small city Medium-sized city or suburb Large city or suburb Very large city or suburb 4,445 32.5 12.3 9,438 30.8 12.4 23,837 28.9 11.0 16,096 29.3 10.9 12,504 28.3 10.8 7,612 25.9 8.9 Self-reported overall academic performance Above average Slightly above average Average Below average 24,640 21.6 6.6 18,688 28.0 9.7 28,609 34.0 14.2 5,652 40.6 20.7 Plans to complete four years of college 50,364 23.9 6.9 Dbes not plan to complete four years of college 25,379 39.1 19.5 Plansto enter the armed forces Male Female 8,317 31.2 13.7 2,644 30.4 12.3 Does not plan to enter the armed forces Male Female 25,621 26.1 10.0 34,669 30.1 11.0 Importance of religion Very important Important Not/somewhat important 20,637 19.2 5.9 25,166 29.5 10.5 33,104 35.1 15.2 Source: Centers for Disease Control and Prevention, Office on Smoking and Health (unpublished data). 48 Epidemiology prezlenting Tobacco Use Among Young People ivere less likely to have smoked than male dropouts (33 VS. 52 percent). White high school students and graduates were more likely than their black counterparts to have smoked in the past week (19 vs. 6 percent). White dropouts were also more likely to have smoked than were black dropouts (46 vs. 17 percent). Data on past- month smoking for 16- through l&year-old high school seniors and similar-aged youth who reported that they had dropped out of school are available from the NHSDA (Kopstein and Roth `1993). About 28 percent of white students and 72 percent of white dropouts were past- month smokers, and 7 percent of black students and 30 percent of black dropouts were past-month smokers. Among Hispanic 16- through l&year-olds, however, past- month smoking prevalence was less divergent between students (25 percent) and dropouts (27 percent). Pirie, Murray, and Luepker (1988), using surveys conducted in Minnesota, also reported a higher prevalence of smoking among dropouts. Age or Grade When Smoking Begins Smoking initiation at a young age increases the subsequent risk of heavy smoking (Escobedo et al. 1993; Taioli and Wynder 1991) and of smoking-attributable mortality (USDHHS 1989b). As is discussed in detail in Chapter 4 (see "Developmental Stages of Smoking"), smoking initiation is a complex process that can occur over a number of years. The present analysis examined two points in this process: the age a person first tries a cigarette, and the age a person begins smoking daily. Because some initiation occurs after the adolescent years, the analysis began with self-reported data re- called by adults in the 1991 NHSDA (Table 7). The analysis was further restricted~to adults aged 30 through 39 because virtually all initiation occurs before the age of 30 (CDC 1991b; SAMHSA, unpublished data) and be cause virtually all of the increased mortality that results from cigarette smoking occurs after the age of 40 (Na- tional Center for Health Statistics [NCHSI 1992a; Table 7. Cumulative percentages of recalled age at which a respondent first tried a cigarette and began smoking daily, among persons aged 30-39, National Household Surveys on Drug Abuse, United States, 1991 Age (years) Persons who had Persons who had All persons* ever tried a cigarette ever smoked daily First tried a Began First tried a First tried a Began cigarette smoking daily cigarette cigarette smoking daily < 12 14.1 < 14 29.7 < 16 48.2 < 18 63.7 I 18 68.8 < 20 71.0 ~25 76.6 <30 77.4 539 78.0 Never smoked 100.0 Mean age NA 0.9 3.9 12.2 26.0 34.9 37.8 46.5 48.1 49.0 100.0 NA 18.0 15.6 1.9 38.0 36.7 8.0 61.9 62.2 24.9 81.6 81.9 53.0 88.2 89.0 71.2 91.0 91.3 77.0 98.2 98.4 94.8 99.3 99.4 98.1 100.0 100.0 100.0 NA+ NA NA 14.5 14.6 17.7 Source: Centers for Disease Control and Prevention, Office on Smoking and Health (unpublished data). *All persons (N = 6,388). +NA = Not applicable. Epidemiology 49 Surgeon General's Report Table 8. Age or grade when respondents first tried a cigarette, Teenage Attitudes and Practices Survey (TAPS), National Household Surveys on Drug Abuse (NHSDA), Monitoring the Future Project (MTFP), Youth Risk Behavior Survey (YRBS), United States, 1989,199l Age /grade* 5 12 years/< grade 6 13-14 years/grades 7-8 15-16 years/grades 9-10 > 16 years/> grade 10 Never smoked TAPS+ NHSDAX MTFP_ YRBS* % 70 70 70 10.1 25.2 18.5 19.2 11.4 14.5 21.6 17.7 22.0 16.6 14.9 15.9 8.2 3.9 5.3 5.7 48.3 39.9 39.8 41.4 Sources: 1989 TAPS: Centers for Disease Control and Prevention (CDC), Office on Smoking and Health (OSH) (unpublished data); 1991 NHSDA: CDC, O!SH (unpublished data); 1991 MTFP: Institute for Social Research, University of Michigan (unpublished data); 1991 YRBS: CDC, Division of Adolescent and School Health (unpublished data). *In TARS, the NHSDA, and the YRBS, respondents reported the age at which they had first smoked; in the MTFP, respon- dents reported the grade in which they first smoked. +Includes 17- and 18-year-old respondents to the 1989 TAPS who had completed the 11th grade and who still attended school. Response categories were constructed using the questions, "Have you ever smoked a cigarette?" and "How old were you when you smoked your first whole cigarette?"(N = 687). %rcludes respondents to the 1991 NHSDA between the ages of 17 and 18 years who had completed the 11th grade and responded to the question, "About how old were you when you first tried a cigarette?" (N = 979). SIncludes high school senior respondents to the 1991 MTFP survey who responded to the question, "When if ever did you first do each of the following things . . Smoke your first cigarette?" (N [weighted] = 2,012). &Includes 12th-grade respondents to the 1991 YRBS who responded to the question, "How old were you when you smoked a whole cigarette for the first time?" (N = 3,127). Table 9. Age or grade when respondents began smoking daily, National Household Surveys on Drug Abuse (NHSDA), Monitoring the Future Project (MTFP), Youth Risk Behavior Survey (YRBS), United States, 1991 NHSDA+ MTFP* YRBS_ Age/grade* 70 70 70 5 12 years/l grade 6 3.3 2.3 3.3 13-14 years/grades 7-8 4.0 8.5 6.1 15-16 years/grades 9-10 10.4 11.9 10.2 > 16 years/> grade 10 4.6 6.0 4.5 Never smoked daily 77.5 71.2 76.0 Sources: 1991 NHSDA: Centers for Disease Control and Prevention (CDC), Office on Smoking and Health (unpublished data); 1991 MTFP: Institute for Social Research, University of Michigan (unpublished data); 1991 YRBS: CDC, Division of Adolescent and School Health (unpublished data). *In the NHSDA and the YRBS, respondents reported the age at which they had begun smoking daily; in the MTFP, respon- dents reported the grade in which they had begun smoking daily. `Includes 17- and l&year-old respondents to the 1991 NHSDA who had completed the 11th grade who responded to the question, "About how old were you when you first started smoking daily?" (N = 959). %xludes high school senior respondents to the I991 MTF'P survey who responded to the question, `When, if ever, did you first do each of the following things . . Smoke cigarettes on a daily basis?" (N lwtd.1 = 2,074). %xludes 12th-grade respondents to the 1991 YRBS who responded to the question, "How old were you when you first started smoking cigarettes regularly? (at least one cigarette every day for 30 days)" (N = 3,074). 50 Epidemiology p,a,vn ting Tobacco Use Among Young People USDHHS 1989b). Since the recalled age at initiation is often 10 or more years younger than the age of the respondent at the time of the survey, recall bias may affect the reliability of these estimates. In the 1991 NHSDA, 69 percent of respondents aged 30 through 39 years reported trying a cigarette by age 18. Of all persons who had ever tried a cigarette, 88 percent had tried their first cigarette by age 18. The mean age of first trying a cigarette was 14.5 years. Thirty-five percent of the respondents had become daily smokers by age 18. Of those who had ever sinoked daily, 71 percent had smoked daily by age 18. The mean age of becoming a daily smoker was 17.7 years. Surveys conducted in 1991 among school-aged stu- dents, while lacking information on postadolescent ini- tiation, provide information of more recent initiation patterns (i.e., during the 1980s and early 1990s). Among 12th~grade students surveyed in 1991,22 percent of TAPS respondents, 40 percent of NHSDA respondents, 40 per- cent of MTFI' respondents, and 37 percent of YRBS re- spondents first tried a cigarette by age 14 (Table 8). About 60 percent of the respondents in the NHSDA, the MTFP, and the YRBS and about 50 percent of the TAPS respondents had smoked by their senior year. Daily cigarette use began by age 16 (or the 10th grade) for 18 to 23 percent of respondents to the NHSDA, the MTFP, and the YRBS (Table 9). By their senior year, 22 to 29 percent of these respondents had become daily smokers. Other Patterns of Smoking Two of the surveys gathered further information about smoking patterns-the number of days per month an adolescent smoked and the number of cigarettes the adolescent smoked per day. In the 1991 YRBS, responses indicated that in general, the greater number of days students reported smoking during the 30 days preceding the survey, the greater the number of cigarettes they smoked per day (Table 10). For example, 49 percent of students who smoked cigarettes on only one or two days during the preceding 30 days smoked fewer than one cigarette per day; among students who smoked ciga- rettes on all 30 days, 47 percent smoked 11 or more per day. Smoking patterns were also reported recently by Moss et al. (1992), using 1989 TAPS data (Table 11). About 41 percent of teenage smokers-whether male or female-smoked every day, and about one in four smoked on fewer than five of the preceding 30 days. The percentage of smokers who smoked every day increased with increasing age; 48 percent of 16- through l&year- old smokers smoked every day. About twice as many white as black teenagers smoked every day (42 vs. 22 percent), and blacks were more likely than whites to have smoked on fewer than five days. Non-Hispanics were more likely than Hispanics to smoke every day. Sixteen percent of 12- through l&year-old TAPS respondents who smoked during the week preceding the survey smoked 20 or more cigarettes daily. Males smoked more cigarettes daily than females. Older stu- dents smoked more cigarettes daily than younger stu- dents; 47 percent of 16- through l&year-old smokers and 11 percent of 12- and 13-year-old smokers reported smoking 10 or more cigarettes daily. Whites smoked more cigarettes daily than blacks, and non-Hispanics Table 10. Percent distribution of the number of cigarettes smoked per day, by the number of days on which cigarettes were smoked during the 30 days preceding the survey, Youth Risk Behavior Survey, United States, 1991 Number of days cigarettes were smoked 20 Total N 1-2 49.2 29.2 18.0 1.7 1.0 0.2 100 756 3-5 25.3 29.2 41.5 3.6 0.4 0.0 100 452 6-9 7.0 32.5 54.4 5.8 0.4 0.0 100 273 lo-19 7.4 13.0 66.5 10.8 1.8 0.4 100 326 20-29 0.7 4.6 61.4 27.9 5.4 0.0 100 294 30 0.1 0.3 26.5 26.0 36.6 10.8 100 803 Average 14.8 15.0 37.2 14.8 14.1 4.0 100 2,904 Source: Centers for Disease Control and Prevention, Division of Adolescent and School Health (unpublished data). Epidemiology 51 Surgeon General's Report Table 11. Percentage of current smokers by the number of days smoked during the past month and the average number of cigarettes smoked daily, by gender, age, and race/Hispanic origin, Teenage Attitudes and Practices Survey, United States, 1989 Number of days Number of cigarettes smoked during past month* smoked daily+ Every Category <5 5-9 10-29 day <5 5-9 l&19 220 Overall 24.1 8.7 26.4 40.8 37.9 20.4 25.7 16.0 Gender Male 23.9 8.5 26.6 41.0 33.9 19.3 27.6 19.2 Female 24.3 8.9 26.2 40.6 42.7 21.6 ' 23.5 12.1 Age (years) 12-13 51.9 8.3* 23.3 16.5t 64.3 24.6* 11.0* 0.0 14-15 28.4 9.8 34.5 27.3 55.5 17.2 23.0 4.3* 16-18 20.0 8.4 24.1 47.5 31.6 21.1 27.2 20.1 Race White 23.4 8.4 26.2 42.0 36.6 20.1 26.5 16.8 Black 37.0 15.0* 26.5 21.6 60.3 20.5t 16.3t 2.9* Hispanic origin Hispanic 30.7 11.2* 31.9 26.3 59.2 22.5 11.6s 6.6% Non-Hispanic 23.5 8.5 26.0 42.0 36.3 20.2 26.9 16.7 Source: Moss et al. (1992). *Excludes unknown number of days smoked. `Excludes unknown number of cigarettes smoked daily and none smoked during the past week. SEstimate does not meet standards of reliability or precision (< 30 percent relative standard error). were heavier smokers than Hispanics. Thus, not only were black and Hispanic adolescents less likely to smoke than whites, but those who did smoke, smoked fewer cigarettes each day than their white adolescent counter- parts. On average, persons 12 through 18 years old who smoked the week before the survey (N = 1,099) smoked 9 cigarettes each day. Males smoked IO cigarettes daily and females smoked 8. Whites averaged 9 cigarettes per day and blacks averaged 6 (1989 TAPS, CDC, Office on Smoking and Health [OSHI, unpublished data). The overall average for adult smokers is 19 cigarettes a day (CDC 1992aI. Initiation Continuum of Smoking The 1989 Surgeon General's report on smoking and health described the continuum of smoking be- havior as one that occurs in four stages: initiation, experimentation, regular smoking, and dependence or addiction (USDHHS 1989b). The report also ac- knowledged a preparatory stage that occurred before any initial smoking (Flay et al. 1983). These five stages are examined in detail in Chapter 4 (see "Develop- mental Stages of Smoking"). Data from the 1989 TAPS were used to create an initiation continuum similar to the smoking continuum for adults that was described in the 1989 Surgeon General's report (Pierceand Hatziandreu 199O;USDHHS 1989b). This initiation continuum incorporates mea- sures of smoking behavior and measures of the possibil- ity that a respondent will smoke in the future. In 1989, 54.5 percent of persons 12 through 18 years old reported that they had never smoked a cigarette, not even a few puffs (TabIe 12). These respondents were asked to report (1) whether they thought they would try a cigarette soon ("yes, " "no," and "don't know"), (2) whether they would 52 Epidemiology Prewnting Tobacco Use Among Young People Table 12. Percent distribution of an initiation continuum for cigarette smoking among persons aged 12-18 yeas, by age, gender, and race/Hispanic origin, Teenage Attitudes and Practices Survey, United States, 1989 Uptake continuum category Age (years) Gender Overall lZ-14 15-16 17-18 Male Female Race/Hispanic origin White/ Black/ non- non- His- His- panic panic Hispanic 1. Never tried smoking, not susceptible 44.3 2. Never tried smoking, susceptible 10.2 3. Tried smoking, not a whole cigarette, not susceptible 7.9 4. Tried smoking, not a whole cigarette, susceptible 3.3 5. Smoked l-99 cigarettes, 13.5 but none in the f&t 30 days, and not intending to smoke in a year 6. Smoked l-99 cigarettes, but none in the last 30 days, and might smoke in a year 7. Smoked 2 100 cigarettes, but none in the last 30 days, and not intending to smoke in a year 8. Smoked 2 100 cigarettes, but none in the last 30 days, and might smoke in a year 9. 10. 11. Smoked l-99 cigarettes, at least some in the past 30 days Smoked 2 100 cigarettes and smoked on l-19 days during the past 30 days Smoked at least 100 cigarettes and smoked on at least 20 days during the past 30 days 4.1 0.9 0.4 5.9 2.2 7.3 55.5 40.1 32.9 42.0 46.8 42.3 54.0 40.3 15.8 8.4 4.3 10.1 10.3 9.4 10.5 15.9 6:6 4.3 7.5 4.2 0.2 0.2 3.7 0.7 1.3 8.3 9.5 8.6 7.2 7.1 12.7 8.0 3.2 2.1 3.8 2.7 2.6 5.2 5.4 16.6 18.8 13.6 13.4 14.6 9.6 12.6 4.8 3.1 4.2 3.9 4.4 1.9 5.4 1.0 1.9 1.2 0.7 1.2 0.0 0.8 0.4 0.7 0.4 0.4 0.5 0.3 0.5 7.3 7.4 5.8 5.9 6.3 4.1 5.6 2.6 3.8 2.3 2.0 2.6 0.6 1.7 7.5 15.5 7.8 6.7 9.1 1.2 4.0 Source: Centers for Disease Control and Prevention, Office on Smoking and Health (unpublished data). Epidemiology 53 Surgeon General's Report smoke a cigarette if one of their best friends were to offer them one ("definitely yes," "probably yes," "probably not," "definitelynot," and "don't know"), and (3) whether they thought they would be smoking cigarettes in one year ("definitely yes," "probably yes," "probably not," "definitely not," and "don't know"). Never smokers who answered "no" to the first question, "definitely not" to the second question, and "definitelynot" to the third question were categorized as "not susceptible" to smoking. Those who answered these three questions in any other way were considered susceptible to smoking in the future (Pierce et al. 1993). According to these criteria, 44 percent of all TAPS respondents had never tried a cigarette and were not considered susceptible to smoking, and 10 percent had never tried smoking but were con- sidered susceptible. Adolescents who had tried smoking but had not smoked a whole cigarette accounted for 11 percent of TAPS respondents; 8 percent were judged to be not susceptible to smoking in the future, and 3 percent were judged susceptible. Those who had smoked at least one cigarette were only asked question 3, above, concerning whether or not they thought they would be smoking in a year. A large category (14 percent of all respondents) was composed of those who had smoked at least 1 but fewer than 100 cigarettes, who had not smoked in the preceding 30 days, and who definitely did not intend to smoke in a year. Another 4 percent had smoked from 1 to 99 cigarettes, had not smoked in the preceding 30 days, and were not definite in their resolve to not be smoking in a year. Slightly more than 1 percent of TAPS respondents had smoked at least 100 cigarettes but had not smoked in the preceding 30 days; these respondents are considered to be former smokers (USDHHS 1989b, 199Ob). Finally, among the 15 percent of respondents who smoked in the preceding 30 days, about 45 percent (6 percent of all respondents) had smoked fewer than 100 cigarettes in their lifetime. Although current smok- ers, these persons were still at a relatively early stage in the process of smoking initiation. Among those who had smoked at least 100 cigarettes and had smoked in the preceding month, more than three-fourths (7 percent of all respondents) had smoked on 20 or more of those 30 days. The distribution of this continuum was similar for males and females. White adolescents were more likely to be further along the continuum than were Hispanic and black adolescents. Cigarette Brand Preference Knowing what brands of cigarettes are preferred by young smokers may aid the development of smoking prevention programs and may provide insight into the influence that cigarette advertising may have on YOU% people. ln 19781980, the NHE assessed the brands of ciga- rettes most often used by current smokers (CDC, OSH, unpublished data). Among 707 respondents who were 18 or 19 years old, the most commonly used brands were Marlboro (37 percent), Kool (14 percent), Salem (10 per- cent), Winston (9 percent), Newport (8 percent), Virginia Slims (5 percent), Merit (4 percent), Benson & Hedges (3 percent), and Camel (2 percent). Ten percent of females and no males used Virginia Slims. Among whites, Marlboro (42 percent), Kool (10 percent), Winston (10 percent), Salem (8 percent), Virginia Slims (6 percent), and Newport (6 percent) were the most commonly used brands. Among blacks, Kool (46 percent), Newport (25 percent), Salem (20 percent), and Benson & Hedges (6 percent) were the most commonly smoked brands. In the 1989 TAPS, adolescent respondents who generally bought their own cigarettes were asked what brand they usually purchased. More than two-thirds of these smokers usually purchased Marlboro (Table 13). Preference for Marlboro did not differ appreciably by gender, Hispanic origin, age, or region of the country. White adolescent smokers were much more likely to smoke Marlboro cigarettes than were black adolescent smokers (71 vs. 9 percent). The next most popular brands, Newport and Camel, each accounted for only 8 percent of the overall population's preference. Black smokers, however, were much more likely to smoke Newport cigarettes than were white smokers (61 vs. 6 percent), although sample sizes of blacks were small. Smokers who resided in the Northeast and the Midwest were more likely to smoke Newport cigarettes than were smokers in the South and the West. Among white adolescents, Newport was more popular in the Northeast (14 percent) and the Midwest (7 percent) than in the South (1 percent) and the West (1 percent) (CDC 1992b). The Camel brand was more popular among male (11 percent) than female smokers (5 percent), among white (8 percent) than black smokers (3 percent), and among smokers residing in the West (18 percent) than among those residing in the other three regions (from 4 to 7 percent). Several nonnational studies conducted since the 1989 TAPS suggest that Camel cigarettes may be gaining in popularity among young smokers In a 1990 survey of ninth-grade students in 10 U.S. communities included in the Community Intervention Trial for Smoking Cessa- tion (COMMIT) evaluation, 43 percent of smokers who usually bought their own cigarettes bought Marlboro, 30 percent bought Camel, and 20 percent bought New- port (CDC 1992b). As TAPS data also indicated, adoles- cent smokers residing in communities in the western 54 Epidemiology prL~wting Tobacco Use Among Young People Table 13. Percent distribution of cigarette brands that 12-18-year-old current smokers* reported usually buying, by gender, race/Hispanic origin,' age, and region, Teenage Attitudes and Practices Survey, United States, 1989 Category Benson & Number Marlboro Newport Camel Winston Hedges Salem Kool Merit Vantage Other OverallS 865 Gender Male 477 FemaIe 388 Race White 807 Black 41 Hispanic origin Hispanic 46 Non-Hispanic 817 Age (years) 12-15 195 16-18 670 Region Northeast 184 Midwest 247 south 281 West 153 Overall market share, 1989 68.7 8.2 8.1 3.2 1.5 1.4 1.0 0.5 0.1 7.3 68.9 7.3 10.9 3.6 0.5 0.2 1.9 0.7 0.2 6.0 68.4 9.4 4.6 2.6 2.9 2.9 0.0 0.3 0.0 8.9 71.4 5.6 8.4 3.4 1.0 1.3 0.6 0.5 0.1 7.6 8.7 61.3 3.1 0.0 9.7 3.3 10.9 0.0 0.0 2.9 60.9 12.8 7.6 0.0 2.8 3.7 5.8 0.0 0.0 6.5 69.1 8.0 8.1 3.3 1.5 1.3 0.8 0.5 0.1 7.3 74.8 6.1 8.7 2.5 0.9 0.4 67.0 8.8 7.9 3.3 1.7 1.6 1.1 1.0 0.0 1.1 2.1 0.0 5.9 0.0 0.0 6.5 0.6 0.1 7.8 68.4 16.2 4:l 0.0 2.3 0.0 70.2 10.0 7.3 3.4 2.2 0.0 67.2 5.b 6.1 6.2 1.1 2.9 69.6 2.0 18.1 0.7 0.6 2.3 0.6 0.5 7.9 0.5 0.0 5.3 0.4 0.0 9.1 0.6 0.0 6.2 26.3 4.7 3.9 9.1 6.2 3.9 3.8 2.5 33.7 Sources: Centers for Disease Control (1992b); Maxwell (1992). *Persons who reported smoking on one or more of the 30 days preceding the survey. `Excludes the racial category "other" (N = 17). Ethnicity for two persons was unknown. `Data were weighted to provide national estimates. United States showed more preference for Camel ciga- rettes than did smokers from other regions of the nation. Other studies conducted after TAPS report rates of Camel preference among adolescent smokers that are consis- tent with the COMMIT survey results (DiFranza et al. 1991; Pierce, Gilpin, et al. 1991). In June and July 1992, the George H. Gallup Inter- national Institute 0992) conducted a telephone survey of a nationwide sample of 1,125 youths 12 through 17 years old. Smokers (those who reported having smoked at least one cigarette during the 30 days preceding the interview) were disproportionately oversampled, and the data were weighted to represent the adolescent population. Smokers were asked, `Thinking now about the last time you bought cigarettes for yourself, what brand did you happen to buy on that occasion?" Marlboro was the brand bought by 53 percent of these teenage smokers, Camel by 16 percent, and Newport by 8 percent. The most popular brand among blacks in this survey was Newport (54 percent preference). Epidemiology 55 Surgeon Generul's Reporf Trends in Cigarette Smoking Current Smoking Ever Smoking Data from the NTIS, the NHSDA, and the MTFP suggest that the prevalence of ever smoking among ado- lescents has declined since the 1970s (Table 14). In the NHSDA, the prevalence of smoking among youths 17 through 19 years old declined from 78 percent in 1979 to 64 percent in 1991, an average decline of 1.2 percentage points per year. In the MTFP, the prevalence among 17- and 18-year-olds decreased from 76 percent in 1977 to 62 percent in 1992, an average decline of 0.9 percentage points per year. In the NHIS, the percentage of 18- and 19-year-olds who had smoked at least 100 cigarettes dropped from 41 percent in 1974 to 25 percent in 1991, an average decline of 1 .O percentage points each year. NHIS data have been used to examine historical trends in smoking by reconstructing the prevalence of cigarette smoking for the decades in this century before systematic surveillance of cigarette smoking was con- ducted WSDHHS 1980,1985,1991b; Harris 1983). Us- ing information on a respondent's date of birth, age at initiation of fairly regular smoking, and duration of abstinence (for former smokers), the smoking status of the respondent can be assessed for any given year. For this report, the reconstructed prevalence of smoking among those aged 10 through 19 years is reported for the years 1920 through 1980. ,. Except for 1980, smoking during this 60-year pe- riod was more common among white and black ado- Iescent males than among white and black adolescent females (Figure I). The prevalence of cigarette smoking Figure 1. Trends in the reconstructed prevalence* of cigarette smoking among IO-19-year-olds, by gender and race, United States, 1920 -1980 25 1 m White males IIII~II Black males - White females - - Black females 0 I I I I I 1 1920 1930 1940 1950 1960 1970 1980 Year Source: U.S. Department of Health and Human Services (1991b). Data sources are the 1970,1978,1979,1980, and 1987 National Health Interview Surveys. The smoking prevalence for each of the years indicated was calculated for people who would have been 10-19 years old in each of those years by using the survey respondents' date of birth, age when they first began smoking regularly, and age when they quit smoking (see Appendix 2). 56 Epidemiology Pmwrlting TO~UCCO Use Among Young People Table 14. Trends in the prevalence (%I of ever smoking among young people, National Teenage Tobacco Surveys (NTIS), National Household Surveys on Drug Abuse (NHSDA),Monitoring the Future Projeci (MTFP), National Health Interview Surveys (NHIS), United States, 1968-1992 Year NITS' NHSDA' MTFPt NHIS_ 1968 1970 1972 1974 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 36.1 40.8 39.2 41.3 69.5 64.1 67.8 34.0 78.1 72.6 63.2 66.2 61.4 63.6 41.1 75.4 75.8 75.3 36.7 74.0 39.3 71.0 34.1 71 .o 70.1 70.6 34.5 69.7 68.8 29.8 67.6 67.2 26.2 66.4 27.7 65.7 64.4 27.6 63.1 25.3 61.8 Sources: NTTS: U.S. Department of Health, Education, and Welfare (USDHEW) (1972,1976,1979b); NHSDA: Centers for Disease Control and Prevention (CDC), Office on Smoking and Health (OSH) (unpublished data on 1974-1991 surveys); MTFP: Johnston, O'Malley, Bachman (in press); NHIS: CDC, OSH (unpublished data on 1974-1991 surveys). `NTTS, aged 17-18 years. Published reports (USDHEW 1972,1976,1979b) merge never smokers and experimenters (those who tried or experimented with smoking, but who had not yet smoked 100 cigarettes) into one category. By definition, therefore, the NTIS will underestimate the percentage of ever smokers. The trends, however, use the same definition. `NHSDA, aged 17-19 years. Those who reported in 1974,1976, and 1977 that they were current smokers and those who were not current smokers but who responded "yes" to the question, "Have you ever smoked cigarettes?" were classified as ever smokers for those years. For the years 1979 through 1991, ever smoking status was determined by response to the question, "About how old were you when you first tried a cigarette?" The prevalence of ever smoking is the complement of the response "Never tried a cigarette." tMTFP high school seniors, aged 17-18 years. Based on response to the question, "Have you ever smoked cigarettes?" `NHIS, aged 18-19 years. Based on response to the question, "Have you smoked at least 100 cigarettes in your entire life?" Those who had smoked at least 100 cigarettes by the time of the survey were classified as ever smokers. `Available information from published sources (USDHEW 1972,1976,1979b) do not permit exact comparisons with the 1989 TAPS data. Epidemiology 57 Surgeon General's Report remained higher among white adolescent males than among black adolescent males. Smoking prevalence gradually increased among white males during the six decades covered by the data. Among black males, preva- lence declined between 1950 and 1980. Among female adolescents, the reconstructed prevalence of current smoking increased steadily from 1920 through 1980; in 1980, the prevalence among fe- males surpassed that among males for the first time during the six-decade study period. Prevalence among white females has been higher than among black females since 1950. The data indicate a sharp increase in female smoking prevalence between 1970 and 1980. Trends in current smoking prevalence over the past two decades indicate that for both males and females, past-month smoking declined sharply in the late 1970s or, early 1980s (Table 15). Progress then slowed consider- ably, especially for males. In the MTFP surveys, the past- month smoking prevalence among males actually increased from 27 percent in 1981 to 29 percent in 1992; in the NHSDA and the THIS, male smoking prevalence was about the same in 1985 and in 1991. The prevalence among adolescent females in the MTFP and NHIS surveys was only slightly lower in 1991 and 1992 than in 1985; in the 1991 NHSDA, female smoking prevalence was about the same as in 1985. By the early 198Os, smoking was gener- ally more common among females than among males. By 1991, however, adolescent females and males had almost equivalent smoking prevalence. In all three surveys with information on race, the prevalence of current smoking declined during the late 1970s or early 1980s for both black and white older adolescents (Table 16). In the middle 197Os, current smoking was almost equally common among blacks and whites. At the end of that decade, black adolescents were less likely to be current smokers than white adoles- cents; this trend continued during the 1980s. Among white high school seniors in the MTF'P, current smoking was more prevalent in 1992 (32 percent) than in 1981(30 percent). In all three surveys, prevalence among older white adolescents was slightly higher in 1991 and 1992 than it was in 1985. Wallace and Bachman (1991) reported that white high school seniors were more than twice as likely as black high school seniors to report smoking in the past month, even after statistical control was made for factors such as parental education, number of parents living at home, urban or rural location, educational plans, academic per- formance, and religious attitudes and practices. MTJ!P trend data are available for daily smoking among racial and ethnic subgroups (Bachmanet al. 1991). In general, for Asian, black, white, Hispanic, and Ameri- can Indian male and female high school seniors, the prevalence of daily smoking declined from 1976-1984. The decline continued at a reduced rate during the late 1980s for most groups and ceased altogether among white males. Overall, the prevalence of daily smoking among high school seniors was 29 percent in 1976,21 percent in 1980, and 17 percent in 1992. Among males, the preva- lence was 28 percent in 1976,19 percent in 1980, and 17 percent in 1992; among females, 29 percent smoked daily in 1976, 24 percent in 1980, and 17 percent in 1992. Among whites, the prevalence of daily smoking de- clined from 29 percent in 1976 to 22 percent in 1980; the prevalence was 20 percent in 1992. Among blacks, the prevalence of daily smoking declined from 27 percent in 1976 to 16 percent in 1980 and continued to decline to 4 percent in 1992 (Bachman, Johnston, O'Malley 198Oa, 1981; ISR, University of Michigan, unpublished data). Data on smoking among the nation's high school seniors have also been reported as a function of parental education (NCHS 1993). Interestingly, the prevalence of past-month smoking decreased slightly from 1980 through 1991 among those seniors whose parents had completed fewer years of formal education and increased slightly during that period among those seniors whose parents had relatively more years of formal education. For example, among those seniors whose parents, on average, did not graduate from high school, the preva- lence of past-month smoking decreased from 33 percent in 1980 to 31 percent in 1991; among seniors whose parents graduated from high school, prevalence of smok- ing was 34 percent in 1980 and 29 percent in 1991. Among seniors whose parents had some postgraduate educa- tion, the prevalence of smoking was 24 percent in 1980 and 27 percent in 1991. Age or Grade When Smoking Begins The age at which people become regular cigarette smokers has been measured in national surveys con- ducted in 1955,1966, 1970,1978,1979,1980,1987, and 1988 (Haenszel, Shimkin, Miller 1955; NCHS 1970; USDHHS 1980, 1989b, 1991b; CDC 1991b). Data from the 1955 Current Population Survey (Haenszel, Shimkin, Miller 1955) suggest that during the first half of the century, people became regular smokers at progressively younger ages. The data for males are limited, however, because before 1974 many of the reports for men were provided by proxy respondents. To reduce proxy responses, Ahmed and Gleeson (NCHS 1970) limited their analysis of data from the 1966 Current Population Survey to females. These investiga- tors concluded that between 1955 and 1966, U. S. women began smoking at an earlier age. For the present report, the likelihood of having become a regular cigarette smoker by age 18 was deter- mined for females surveyed in the 1970,1978-1980, and 58 Epidemiology preventing TO~UCCO Use Among Young People Table 15. Trends in the prevalence (o/o) of current smoking* among young people, by gender, National Teenage Tobacco Surveys WITSl, National Household Surveys on Drug Abuse (NHSDA), Monitoring the Future Project (MTFP), National Health Interview Surveys (NHIS), United States, 1968-1992 Year N-l-l-S NHSDA MTFP NHIS Males Females Males Females Males Females Males Females (aged 17-18 years) (aged 17-19 years) (aged 17-18 years) (aged 18 -19 years) 1968 34.0 1970 37.8 1972 31.2 1974 32.6 1976 1977 1978 1979 19.6 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 21.0 24.1 26.0 26.4 47.8 35.1 39.0 38.7 52.0 47.2. 27.0 41.7t 41.7t 35.6 37.3 27.8 26.7 28.3. 32.9 28.9 20.2 27.0 27.0 37.7 36.7 34.5 31.2 26.8 26.5 26.8 28.0 25.9 28.2 27.9 27.0 28.0 27.7 29.1 29.0 29.2 39.1 39.7 38.1 37.1 33.4 31.6 32.6 31.6 31.9 31.4 30.6 31.4 28.9 29.0 29.2 27.5 26.1 36.9 30.8 30.6 33.5 29.5 34.2 24.9 27.8 23.3 31.4 20.1 24.5 21.6 20.9 19.6 23.1 21.7 18.0 22.0 20.6 Sources: N'ITS: U.S. Department of Health, Education, and Welfare (USDHEW) (1972,1976,1979b); NHSDA: Centers for Disease Control and Prevention (CDC), Office on Smoking and Health (OSH) (unpublished data on 1974-1991 surveys); MTFP: Bachman, Johnston, O'Malley (1980a, b, 1981,1984,1985,1987,1991); Johnston, Bachman, O'Malley (1980a, b, 1982, 1984,1986,1991,1992); Johnston, O'Malley, Bachman (1991a, in press); Institute for Social Research, University of Michigan (unpublished data); NHIS: CDC, OSH (unpublished data in 1974-1991 surveys). *For the NTTS, current smokers are those who state that they smoke less than one cigarette per week, one or more cigarettes per week, or one or more cigarettes a day (USDHEW 1979b). For the NHSDA and the MTFP, current smoking is defined as any cigarette smoking during the 30 days preceding the survey. For the NHIS, current smokers are those who report that they have smoked at least 100 cigarettes and who respond "yes" to the question, "DO you smoke now?" `The 1979 NHSDA determined current smoking status only for those respondents who had smoked at least 100 cigarettes (lifetime). The National Institute on Drug Abuse later published adjusted 1979 estimates using data from the 1982 NHSDA (Miller et al. 1983). The adjusted 1979 estimates used the ratio of the 1982 prevalence estimate, based on the 1979 definition, to the prevalence estimate based on the definition used in other years (i.e., any smoking in the last 30 days, regardless of whether the respondent had ever smoked 100 lifetime cigarettes). This table reports estimates based on the same adjust- ment procedure. rAvailable information from published sources (USDHEW 1972,1976,1979b) does not permit exact comparisons with the 1989 TAPS data. Epidemiology 59 Surgeon General's Report Table 16. Trends in the prevalence (X) of current smoking* among white and black young people, National Household Surveys on Drug Abuse (NHSDAI, Monitoring the Future Project (MTFP), National Health Interview Surveys (NHISI, United States, 1974-1992 NHSDA+ MTPP NHIS Year White Black (aged 17-19 years) White Black (aged 17-18 years) White Black (aged 18-19 years) 1974 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 41.9 47.4 43.0 47.2 42.9 44.3 44.4$ 37.7$ 39.2 20.9 28.6 20.8 33.0 17.6 28.3 7.2 30.5 11.4 38.3 39.7 38.4 34.4 37.0 31.5 34.9 28.7 31.0 25.2 30.1 22.3 31.3 21.2 31.3 21.2 31.0 17.6 31.7 18.7 32.0 14.6 32.2 13.9 32.3 12.8 32.1 12.4 32.5 12.0 31.8 9.4 31.8 8.2 33.6 33.7 33.3 26.3 32.6 30.8 26.1 29.0 28.6 18.5 23.4 18.4 23.4 15.3 23.7 9.4 22.2 10.3 24.9 7.6 Sources: NTTS: U.S. Department of Health, Education, and.Welfare (1972,1976,1979b); NHSDA: Centers for Disease Control and Prevention (CDC), Office on Smoking and Health (OSHI (unpublished data on 1974-1991 surveys); MTFP: Bachman, Johnston, O'Malley (1980a, b, 1981, 1984,.1985,1987,1991); Johnston, Bachman, O'Malley (1980a, b, 1982,19&k 1986,1991,1992); Johnston, O'MaIIey, Bachman (1992a); Institute for Social Research, University of Michigan (unpublished data); NHIS: CDC, DSH (unpublished data on 1974-1991 surveys). *For the NHSDA and the MTFP, current smoking is defined as any cigarette smoking during the 30 days preceding the survey. For the NHIS, current smokers are those who report that they have smoked at least 100 cigarettes and who respond "yes" to the question, "Do you smoke now?" `In the NHSDA, "white" and "black" include respondents of Hispanic origin, except for 1985. tithe 1979 NHSDA determined current smoking status only for those respondents who had smoked at least 100 cigarettes (lifetime). The National Institute on Drug Abuse later published adjusted 1979 estimates using data from the 1982 NHSDA (Miller et al. 1983). The adjusted 1979 estimates used the ratio of the 1982 prevalence estimate, based on the 1979 definition, to the prevalence estimate based on the definition used in other years (i.e., any smoking in the last 30 days, regardless of whether the respondent had ever smoked 100 Iifetime cigarettes). This table reports estimates based on the same adjust- ment procedure. 1987-1988 NHE (Figure 2). The data confirm that women in the United States have started to smoke at increasingly younger ages. The largest differences exist for women who were at least 45 years old at the time of the survey. The initiation curve for 18 through 24year-old females surveyed in 1987 and 1988 is, by age 18, lower than that for 18 through 24year-old females surveyed in 1978 through 1980, which is consistent with the notion that the prevalence of cigarette smoking has declined recently among young females (Table 15). Johnston, (YMalley, and Bachman (1992a) used retrospective reports from h4TFP high school seniors to describe trends in the initiation of daily smoking among seniors. Their data show that the likelihood of becoming a daily smoker at an earlier grade level increased sharply during the early to middle 1970s for the 1976 through 1978 senior classes. From 1975 through 1977, this likeli- hood decreased, and the grade of initiation declined or leveled for the 1979-1986 and 1988 classes. The lifetime 60 Epidemiology praenting Tobacco Use Among Young People Figure 2. Cumulative percentage of females becoming regular cigarette smokers by age 18, by age at time of survey, United States, 1970,1978-1980, and 1987-1988 25 z g 20 L 15 Age at time of survey: - 18-24 years 3 5 7 9 11. 13 15 17 Age when respondent began smoking regularly (years) - 30- Age at time of survey: 25- 35-44years 20- 2 2 & 15- c lo- 3 5 7 9 11 13 15 17 Age when respondent began smoking regularly (years) 25 1 Age at time of survey: 20- 55-64 years 2 15- 8 5 f lo- 3 5 7 9 11 13 15 17 Age when respondent began smoking regularly (years) 40- Age at time of survey: Age at time of survey: 25-34 years 30- 30- 25- 25- 2 2 8 20- 8 % % 20- a 15- a 15- 10- 10- 5- 5- 3 3 5 7 5 7 9 9 11 11 13 13 15 15 17 17 Age when respondent began smoking regularly (years) Age when respondent began smoking regularly (years) 30 30- 25 1 Age at time Age at time of survey: of survey: 25 - 45-54 years 45-54 years 20- 20- F F 8 15- 8 ti ti 15- f, f, lo- lo- 5- 5- 0 0 3 5 7 9 11 13 15 17 Age when respondent began smoking regularly (years) 12- 12- Age at time of survey: Age at time of survey: lo- lo- 2 65 years 2 65 years 8- 8- 5 5 2 2 6- 6- k k 4- 4- 2- 2- 0 0 3 3 5 7 9 11 13 15 17 5 7 9 11 13 15 17 Age when respondent began smoking regularly (years) 3 5 7 9 11 13 15 17 Age when respondent began smoking regularly (years) Age when respondent began smoking regularly (years) Source: National Health Interview Surveys 1970,1978,1979,1980,1987,1988, Centers for Disease Control and Prevention, Office on Smoking and Health (unpublished data). - 1987-1988 Surveys - 1978-1980 Surveys - - 1970 Survey Epidemiology 61 Surgeon Germal's Report prevalence of daily cigarette smoking at aII grade levels increased among the classes of 1989,1990, and 1991. Number of Cigarettes Smoked Each Day Trends in the intensity of smoking among MTFI' high school seniors indicate that since 1976, the propor- tion of heavy smokers (2 one-haIf pack per day) has decreased and the proportion of never smokers has in- creased (Figure 3). For example, in 1976,25 percent of high school seniors had never smoked, and 19 percent were heavy smokers; by 1992, 38 percent had never smoked, and 10 percent were heavy smokers (Bachman, Johnston, 0'MaIIey 1980a; ISR, University of Michigan, unpublished data). Attempts to Quit Smoking Cessation attempts are common among young smokers. In the 1989 TAPS, 74 percent of 12- through l&year-old smokers reported that they had seriously thought about quitting, 64 percent reported that they had tried to quit smoking, and 49 percent reported that they had tried to quit during the previous six months (AIIen et al. 1993). Nearly half of aII smokers among high school se- niors surveyed by the MTFP between 1976 and 1984 reported that they wanted to stop smoking (Table 17). Interest in quitting declined slightly thereafter. About 30 percent of current smokers reported that at one time in their lives they had tried but failed to stop smoking. About 40 percent of daily smokers reported that they had tried at least once to stop smoking but had faiied. The percentage of seniors who at some time had smoked regularly but had not smoked during the 30 days pre- ceding the survey (former smokers) increased sharply for males from 1977 through 1980 and for females from 1977 through 1981 (Figure 4). This measure declined sharply after 1980 for males and after 1981 for females. Table 17. Trends in high school senior smokers' interest in quitting smoking and attempts to quit smoking, by frequency of smoking during the past 30 days, Monitoring the Future Project, United States, 1976-1989 Respondents answering "Yes" Survey Question Do you want to stop smoking now? Among those who smoked at all during the last 30 days 1976 -1979 1980-1984 1985-1989 N (weighted) % N (weighted) % N (weighted) % 3,872 46.1 3,805 47.1 3,418 42.5 Among those who smoked 2 1 cigarette/day during the last 30 days 3,396 46.1 3,262 47.6 2,761 43.9 Have you ever tried to stop smoking and found that you could not? Among those who smoked at all during the last 30 days 4,740 31.5 4,942 31.4 4,534 27.8 Among those who smoked 3,604 38.5 3,464 41.6 2 1 cigarette/day during the last 30 days Source: Centers for Disease Control and Prevention, Office on Smoking and Health (unpublished data). 2,953 39.4 62 Epidemiology pmwnting Tobacco Use Among Young People Figure 3. Trends in the intensity of smoking among high school seniors, Monitoring the Future Project, United States, 1976-1992 45 1 40- 35- 30- 2 25- 8 Never smoked Have smoked but not in the past 30 days . . . . . . . . . . . . . . . . < 1 cigarette/day in the past 30 days ---- l-5 cigarettes/day in the past 30 days II- . . 2 one-half pack/day in the past 30 days 1984 Year 1986 1988 1990 1992 Sources: Bachman, Johnston, O'Malley (1980a, b, 1981,1984,1985,1987,1991); Johnston, Bachman, O'Malley (1980a, b, 1982, 1984,1986,1991,1992); Institute for Social Research, University of Michigan (unpublished data). Figure 4. Trends in the percentage of former smdkers among ever smokers,* by gender, high school seniors, Monitoring the Future Project, United States, 1976-1989 . . . . . . . Male Z?- - Female 16- 14 I 1 I I I I I I I I I I I 1976 1978 1980 1982 1984 1986 1988 Year Source: Centers for Disease Control and Prevention, Office on Smoking and Health (unpublished data). *Percentage of those who had ever smoked regularly who had not smoked during the previous 30 days. Epidemiology 63 161-235 95-3 The trend of cessation is similar to the trend for current smoking prevaIence. Substantial progress occurred in the late 197Os, but this progress slowed considerably in the 1980s. Trends in Knowledge and Attitudes About Smoking Trends in Perceived Health Risks of Smoking Data from the M'TFP allow comparisons of trends in beliefs about the risks associated with cigarette smok- ing and in actual smoking behavior. The decline in the prevalence of ever smoking has been associated with an increase in the percentage of high school seniors who believe that smoking one or more packs of cigarettes each day is a serious health risk (Figure 5). This associa- tion has been observed for both genders and for whites and blacks (Bachman, Johnston, 0'MalIey 198Oa, b, 1981, 1984, 1985, 1987, 1991; Johnston, Bachman, O'Malley 198Oa, b, 1982,1984,1986,1991; ISR, University of Michi- gan, unpublished data). For example, during the early 1980s the percentage of black high school seniors who felt that there is great risk associated with smoking a pack or more per day increased substantially. At the same time, the percentage of black youth who had smoked Surgeon General's Report at all and who had smoked daily declined rapidly. In 1989, over 50 percent of smokers and 74 percent of non- smokers reported that they believed that smoking a pack or more per day is a serious health risk 0989 MTFP, CDC, OSH, unpublished data). The percentage of seniors who believed that smok- ing entails a great risk to health increased from 56 per- cent in 1976 to 69 percent in 1991, and the percentage who believed that the health effects of smoking had been exaggerated decreased from 16 percent in 1981 to 14 percent in 1991 (Table 18). Nonetheless, 3 out of 10 seniors in 1991 still did not believe that heavy smoking poses a serious threat to health. Among 12- through l&year-olds in the 1989 TAPS, 32 percent believed that there is no harm in having an occasional cigarette; 57 percent of smokers in the survey endorsed that statement (Allen et al. 1993). Twenty-one percent of smokers and 3 percent of never smokers be- lieved that it is safe to smoke for only a year or two. Trends in Perceptions About Smoking The percentage of high school seniors surveyed by the MTFP who considered smoking a "dirty habit" in- creased between 198lf66 percent) and 1991 (72 percent) (Table 18). About 73 percent of white and 74 percent of black adolescents now feel this way, compared with only Figure 5. Trends in the percentage of high school seniors who believe that smoking is a serious health risk and in the percentage who have ever smoked, Monitoring the Future Project, United States, 1976-1991 - Ever smoked --/ 1 / , , , , , , t , ( ( / , 1 1976 1978 1980 1982 1984 1986 1988 1990 Year Sources: Bachman, Johnston, O'MaIley (1980a. b, 1981,1984,1985,1987,1991); Johnston, Bachman, O'MalIey (1980a, b, 1982, 1984,1986,1991,1992); Institute for Social Research, University of Michigan (unpublished data). 64 Epidemiology Preoenting Tobacco Use Among Young People 69 percent of whites and 54 percent of blacks surveyed in 1981 (Johnston, Bachman, 0'Malley 1982; ISR, Univer- sity of Michigan, unpublished data). The perception that smoking is a dirty habit has increased among males, females, smokers, and nonsmokers. Fii percent of smokers and 81 percent of nonsmokers classified smok- ing as a dirty habit in 1989 (Johnston, Bachman, O'Malley 1982,1984,1986,1991,1992;Bachman, Johnston,CYMalley 1984,1985,1991; 1981-1989 MTFI', CDC, OSH, unpub- lished data). Between 1977 and 1981, the percentage of seniors who felt that their close friends would not, or did not, approve of their smoking increased substantially (Table 18). The percentages reported for 1981 and 1991, however, were essentially identical. The percentage of senior who believed that adults should be prohibited by law from smoking in certain public places increased from 42 percent in 1977 to 45 percent in 1986 and remained about the same in 1991. TARS data on 12- through Wyear-olds provide further information on beliefs about smoking. In 1989, smokers were from two to five times more likely than never smokers to report that they believed that cigarette smoking helps people relax, reduce stress, feel more comfortable in social situations, reduce boredom, and keep their weight down (Allen et al. 1993). Smokers may also deny the addictive properties of cigarettes (LJSDI-IHS 1988b). TAPS data indicated that 39 percent of smok- ers-but only 11 percent of never smokers-believed that they would be able to quit smoking anytime they wanted. Trends in Perceptions About Smokers The overwhelming majority of high school seniors surveyed by the MTFP did not believe that cigarette smoking makes smokers their age look mature, in con- trol, or independent (Table 18). About half believed that smoking makes smokers look insecure, and more than 60 percent perceived cigarette smoking as something smokers use to try to look mature. between 1981 and 1991, smoking among seniors became less of the behav- ioral norm; fewer than 20 percent of seniors in 1991 reported feeling that smoking is an attempt to conform to such a norm. Responses to the MTFP indicate that the majority of high school seniors prefer to date nonsmokers and that this is becoming a trend. Since 1981, the propor- tion of respondents who prefer to date nonsmokers has increased by over 10 percent, to about 74 percent. The most substantial change occurred among black high school seniors (Figure 6). The percentage of white seniors who preferred to date nonsmokers increased only slightly. Over 85 percent of nonsmokers and Figure 6. Trends in the percentage of high school seniors who prefer to date nonsmokers, by race, Monitoring the Future Project, United States, 1981-1991 55 1 I I I I I I 1 I 1 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 Year Sources: Bachman, Johnston, O'Malley (1981,1984,1985,1987,19911; Johnston, Bachman, O'Malley (1982,1984,1986,1991, 1992); Institute for Social Research, University of Michigan (unpublished data). Epidemiology 65 surgeon General's Report Table 18. Trends in high school seniors' beliefs and attitudes about smoking and smokers, Monitoring the Future Project, United States, 1976,1981,1986,1991 Beliefs and attitudes 1976 1981 1986 1991 About smoking How much do you think people risk harming themselves if they smoke one or tiore packs of cigarettes per day?* (percentage who say great risk) The harmful effects of cigarettes have been exaggerated.+ (percentage who agree) Smoking is a dirty habit. (percentage who agree) How do you think your close friends feel (or would feel) about your smoking one or more packs of cigarettes per day?* (percentage who disapprove) Do you think that people (who are 18 or older) should be prohibited by law from smoking tobacco in certain specified public places? (percentage who say yes) About smokers 56.4 63.3 66.0 69.4 15.5 16.2 13.8 65.5 68.6 71.6 6&Y 73.9 76.2 74.3 42.P 43.0 45.1 44.9 In my opinion, when a guy my age is smoking a cigarette, it makes him look (percentage who agree) . . . like he's trying to appear mature and sophisticated 61.4 62.7 60.8 . . . insecure 42.0 43.6 47.9 . . . conforming 25.4 21.3 16.5 . . . rugged, tough, independent 8.6 9.9 9.8 . . . mature, sophisticated 5.3 4.6 5.0 . . . cool, calm, in control 6.2 5.5 5.3 Sources: Bachman, Johnston, O'MaUey (198Oa, 1987); Johnston, Bachman, O'Malley (198Oa, 1982); Institute for Social Research, University of Michigan (unpublished data). *Possible responses included "no risk," "slight risk," "moderate risk," "great risk," "can't say-drug unfamiliar." Percentages include those who say "great risk." `Possible responses included "disagree," "mostly disagree," "neither," "mostly agree," "agree." Percentages include those who "agree" or "mostly agree." Qossibie responses included "not disapprove," "disapprove," "strongly disapprove." Percentages include those who "disapprove" or "strongly disapprove." 51977 data. &i Epidemiology prtwzting Tobacco Use Among Young People Table 18. Continued Beliefs and attitudes 1976 1981 1986 1991 About smokers In my opinion, when a girl my age is smoking a cigarette, it makes her look (percentage who agree) . . like she's trying to appear mature and sophisticated . . . insecure . . conforming . . . independent and liberated . . mature, sophisticated . , . cool, calm, in control I prefer to date people who don't smoke. (percentage who agree) Smokers know how to enjoy life more than nonsmokers. (percentage who agree) I think that becoming a smoker reflects poor judgment. (percentage who agree) I strongly dislike being near people who are smoking. (percentage who agree) I personally don't mind being around people who are smoking. (percentage who agree) Do you disapprove of people (2 age 18) who smoke one or more packs of cigarettes per day? (percentage who disapprove) 64.6 65.0 64.1 47.4 49.5 52.0 26.5 21.7 19.5 11.2 9.5 9.6 6.9 5.4 4.5 5.5 4.5 4.1 66.5 71.0 74.0 2.8 2.4 3.6 57.0 59.3 61.0 38.2 36.9 33.1 65.9 70.0 75.4 71.4 45.4 48.9 about one-third of smokers preferred to date nonsmok- ers in 1989 (1989 MTF'P, CDC, OSH, unpublished data). Findings from the 1989 TAPS also suggest that few adolescents consider smoking a norm for their age group. Twothirds of 12- through Wyear-old respondents agreed with the statement, "Seeing someone smoking turns me off," and 86 percent (94 percent of never smokers and 51 percent of current smokers> preferred to date nonsmok- ers (Allen et al. 1993). Adolescents seem to be more concerned about people smoking around them. In the MTFP, the percent- age of high school seniors who strongly disliked being near smokers increased between 1986 (45 percent) and 1991(49 percent), and the percentage who reported that they did not mind being around smokers declined (from 38 percent in 198i to 33 percent in 1991) (Table 18). Males were consistently more likely than females to mind being around smokers (Johnston, Bachman, O'Malley 1982, Epidemiology 67 1984,1986,1991,1992; Bachman, Johnston, O'MalIey 1984, 1985, 1991; ISR, University of Michigan, unpublished data). The percentage of female seniors who.did not mind being around smokers changed little over time. From 1981 through 1991, the proportion of high school seniors who did not mind being around people who were smoking decreased by about 50 percent among blacks and by only 5 percent among whites (Figure 7). Smokers' acceptance of being around other smokers re- mained constant, at approximately 70 percent, from 1981 through 1989, whereas the percentage of nonsmokers who did not mind being around smokers decreased from 25 to 21 percent (1981-1989 MTFF surveys, CDC, OSH, unpublished data). Adult Implications of Adolescent Smoking Some notable findings regarding young peopIe's expectations to smoke, or to abstain from smoking, have emerged from the MTFP (see Johnston, O'Malley, Bachman 1992b). In their senior year, respondents who answered one of five questionnaire forms were asked, "Do you think you wiII be smoking cigamttes five years from now?" Overall, about 1 percent said they "definitely' would be smoking in five years, 14 percent said they "prob- ably" would, 27 percent said they probably would not, and 58 percent said they definitely would not flable 19). About 55 percent of past-month smokers and about 45 percent of daily smokers stated that they probably would not or defi- nitely would not be smoking in five years. Of the seniors in the fuII panel, 68 percent indicated that they had not smoked in the 30 days preceding the senior-year survey; 9 percent had smoked less than one Surgeon General's Report cigarette per day; 8 percent had smoked one to five ciga- rettes per day; 7 percent had smoked about one-half pack per day; and 8 percent had smoked a pack or more per day (Table 20). Five years after graduation, the same total proportion (32 percent) were past-month smokers. Some- what more (26 vs. 23 percent), however, were daily smokers. Further, for each smoking group defined by senior-year smoking level, those who continued to smoke increased their frequency of smoking (Tables 20-21). Of the respondents who were nonsmokers at the end of their senior year, 86 percent remained nonsmok- ers five to six years later, whereas only 13 percent of those who smoked one pack each day in their senior year became nonsmokers (Table 20). Those students who smoked one-half pack per day in their senior year were nearly as likely to continue use as were those students who smoked one pack daily; 81 percent of half- pack-a-day smokers &II smoked, and the majority of them increased their rate of smoking (Table 21). Seventy percent of respondents who in their senior year smoked one to five cigarettes per day continued to smoke five years later; most of these continuing smokers increased their rate of use. Even among the seniors who smoked the least &ass than one cigarette per day), 42 percent continued to smoke five to six years later, and two-thirds of these had increased their rate of smoking. When earlier smoking behavior is controlled, se- niors' expectations to smoke had very limited power to predict subsequent smoking behavior (Table 22). Many seniors who smoked one pack per day had expectations of discontinuing use. These expectations showed no relationship to the actual rate of smoking five to six years later. The same is true for those seniors who smoked Table 19. High school seniors predicting whether they will be smoking in five years, by smoking status in senior year, Monitoring the Future Project, United States, 1976-1986 senior classes Predicted likelihood of smoking in five years (o/o)* Senior year smoking status Definitely Probably Probably (use in past 30 days) will will will not None 0.4 1.3 21.0 < 1 cigarette/day 0.5 14.7 56.5 l-5 cigarettes/day 1.8 37.6 44.1 About % pack/day 0.6 57.7 30.3 2 1 pack/day 5.1 62.9 26.7 Total 0.9 14.2 27.0 Source: Institute for Social Research, University of Michigan (unpublished data). o Entnes are row percentages. Definitely Number will not (weighted) 77.3 1,926 28.3 248 16.5 211 11.3 197 5.2 228 58.0 2,810 68 Epidemiology prevating Tobaca, Use Among Young People Figure 7. Trends in the percentage of high school seniors who do not mind being around people who are smoking, by race, Monitoring the Future Project, United States, 1981-1991 5 5 5 5 5 5 .' ,.`"S `, 5 ?? o ?? ,.** `0.. ??? ??? ?? ,.*h ? ???? ???? ???? ??? ???? ??? ? ??? ??? ?? 0 I I I I I I I I I I 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 Year Sources: Bachman, Johnston, O'Malley (1981,19&Q, 1985,1987,1991); Johnston, Bachman, O'Malley (1982,1984,1986,1988, 1991,1992); Institute for sodal Research, University of Michigan (unpublished data). Table 20. Intensity of smoking (%) in senior year of high school, by intensity of smoking 5- 6 years later, Monitoring the Future Project, United States, 1976-1986 Smoking intensity (past 30 days) 5-6 years later (%)* Senior-year < 1 ciga- l-5 ciga- smoking intensity r&e rettes Number Column (use in past 30 days) None i&Y l&Y M pack r 1 pack (weighted) percentage None 85.6 4.9 2.6 2.7 4.1 9,238 67.6 < 1 cigarette/day 57.8 14.4 9.6 7.8 10.4 1,268 9.3 l- 5 cigaretes day per 29.6 8.8 17.2 20.5 23.9 1,058 7.7 About ?4 pack/ day 18.8 4.9 8.7 21.7 46.0 Lo(Jo 7.3 2 1 pack/day 13.4 2.7 4.1 10.1 69.7 1,100 8.1 Total 68.0 5.9 5.0 6.6 Source: Institute for Social Research, University of Michigan (unpublished data). *Entries are row percentages. 14.6 13,665 100.0 Epidemiology 69 Surgeon General's Report Table 21. Direction of change in smoking behavior (%) between senior year of high school and 5 - 6 years later, Monitoring the Future Project, United States, 1976-1986 senior classes Senior-year smoking status (use in past 30 days) Quit Smoking status 5-6 years later" Number Less use Same level More use (weighted) None 85.6 14.4 9,238 < 1 cigarette/day 57.8 14.4 27.8 1,268 l-5 cigarettes/day 29.6 8.8 17.2 44.4 1,058 About `/z pack/day 18.8 13.6 21.7 46.0 1,000 2 1 pack/day 13.2 17.7 40.2 29.0 869 Source: Institute for Social Research, University of Michigan (unpublished data). *Entries are row percentages. Table 22. Smoking intensity 5-6 years after high school, by senior-year smoking status and expectation to smoke in 5 years, Monitoring the Future Project, United States, 1976-1986 senior classes Senior-year smoking intensity (use in past 30 days) and predicted likelihood of smoking in 5 years None Smoking intensity (past 30 days) 5-6 years later* < 1 cigarette l-5 cigarettes 2 1 pack Number /day /day 112 pa&day /day (weighted) None Will smoke Will not smoke Total < 1 cigarette/day Will smoke Will not smoke Total l-5 cigarettes/day Will smoke Will not smoke Total About l/z pack/day Will smoke Will not smoke Total 2 1 pack/day Will smoke Will not smoke Total 55.3 10.6 19.8 8.3 5.9 30 84.7 5.6 2.9 2.5 4.3 1,829 84.2 5.7 3.2 2.6 4.3 1,859 41.7 18.4 19.5 14.0 6.4 36 58.4 14.7 9.7 9.7 7.5 208 55.9 15.2 11.1 10.4 7.3 244 32.3 3.0 15.5 23.0 26.2 83 31.8 5.8 15.9 23.0 23.5 125 32.0 4.7 15.7 23.0 24.6 208 15.5 4.9 6.5 21.0 52.1 115 17.6 2.5 6.5 21.1 52.3 81 16.4 3.9 6.5 21.1 52.2 196 13.3 2.2 3.2 9.6 71.8 153 13.2 1.6 5.3 6.3 73.6 72 13.3 2.0 3.8 8.5 72.4 225 Grand Total 67.0 6.0 5.2 6.6 15.2 2,731 Source: Institute for Social Research, University of Michigan (unpublished data). *Entries are row percentages. 70 Epidemiology Preventing Tobacco Use Among Young People one-half pack-or even as little as one to five cigarettes- per day in high school. Expectations were predictive only for those smokers who smoked less than one ciga- rette per day; 58 percent of those who thought they probably or definitely would be smoking in the future did, in fact, continue to smoke, whereas only 42 percent of those who did not expect to smoke in the future did smoke. Among seniors who had never smoked, less than 2 percent thought they would be smoking in five years (Table 19). This small group did, in fact, have a higher rate of subsequent smoking (45 percent) than never smokers who did not expect to be smoking in five years (15 percent) (Table 22). Thus, the expectation to avoid smoking seemed to make some difference among nonsmokers and very light smokers in high school, although very few seniors in these groups reportecl an expectation to smoke. On the other hand, among light, moderate, and heavy daily smokers, the expectation to abstain from smoking in the future seemed overwhelmed by the strong forces that tend to maintain or advance smoking behavior once it is established. One implication of these results is that young people should be made aware of the strongly addictive nature of nicotine and its ability to overwhelm future good expectations. Clearly, prevention is the major goal, but immediate cessation is of aitical importance for adolescents, even for those who smoke very little in high schooL Smoking and Other Drug Use In Chapter 2, tobacco use is discussed as a possible predictor of other drug use (see "Smoking as a Risk Factor for Other Drug Use" and "Smokeless Tobacco Use as a Risk Factor for Other Drug Use"). The present chapter presents detailed information on high school seniors' usage patterns for cigarettes, alcohol, marijuana, cocaine, inhalants, and smokeless tobacco. Both preva- lence of past-month use and comparisons of the self- reported age at first use of each will be presented. Prevalence of Smoking and Other Drug Use Among high school seniors in the MTFP studies, the majority of alcohol users (60 percent) and smokeless tobacco users (57 percent) did not smoke (Table 23). The majority of marijuana (62 percent), cocaine (68 percent), and inhalant (56 percent) users smoked cigarettes. Ciga- rette smoking prevalence was from 1.9 to 3.9 times higher among users of these drugs than among nonusers. Although most drinkers (60 percent) did not smoke, almost all smokers (88 percent) were drink- ers. Almost one-half (45 percent) of cigarette smok- ers were also marijuana smokers, 11 percent were cocaine users, 5 percent used inhalants, and 33 per- cent used smokeless tobacco (which will be discussed separately later in this chapter). The prevalence of Table 23. Prevalence (%) of cigarette smoking among users of other drugs and prevalence of other drug use among smokers, + high school seniors, Monitoring the Future Project, United States, 1985-1989 Prevalence of Prevalence of smoking among smoking among Prevalence of Prevalence of users of other nonusers of drug use among drug use among Other substances drugs other drugs smokers nonsmokers Alcohol 40.0 10.3 87.6 54.8 Marijuana 62.1 20.3 44.9 11.2 Cocaine+ 68.1 27.2 10.9 2.1 Inhalantst 56.1 28.5 4.8 1.5 Smokeless tobacco5 43.0 22.4 32.5 15.6 Source: Centers for Disease Control and Prevention, Office on Smoking and Health (unpublished data). *Any use of cigarettes or other drugs during the past month. `Includes "coke," "crack," and "rock." %lue, aerosols, laughing gas, etc. SMales only, 1986-1989 senior classes only. Epidemiology 71 Surgeon General's Report other drug use was from 1.6 to 5.2 times more preva- lent among cigarette smokers than nonsmokers. Grade When Smoking and Other Drug Use Begins MTFP data from 1986 through 1989 were merged to observe the grade at which seniors reported trying cigarettes, smokeless tobacco, alcohol, marijuana, and cocaine (Figure 8). Among ever smokers, 31 percent hieci their first cigarette by the sixth grade, and 61 per- cent first smoked by the eighth grade. Among those who had used smokeless tobacco, 23 percent had first done so by the sixth grade, and 53 percent by the eighth grade. Proportionately fewer users of alcohol, marijuana, and cocaine initiated use as early as respondents initiated use of cigarettes and smokeless tobacco. Thirty-four percent of alcohol users, 26 percent of marijuana users, and 6 percent of cocaine users first tried these drugs by the eighth grade. By the 12th grade, only 8 percent of MTFP respon- dents had not tried cigarettes or alcohol; 68 percent had tried both, and 24 percent had tried alcohol but not cigarettes (Table 24). Of those students who had tried both cigarettes and alcohol by 12th grade, almost half (49 percent) had tried cigarettes before trying alcohol; 33 percent had tried both at about the same time. About 30 percent of all students had not tried ciga- rettes or marijuana by the 12th grade (Table 25); 44 percent had tried both, and 22 percent had tried cigarettes but not marijuana. Of those-who had tried both by 12th grade, most students (65 percent) had tried cigarettes before mari- juana; 23 percent had tried both at about the same time. About one-third of seniors (34 percent) had not tried cigarettes or cocaine; 12 percent had tried both, and over half (53 percent) had tried cigarettes but not cocaine (Table 26). Of those who had tried both by 12th grade, 90 percent had tried cigarettes before trying cocaine, and 9 percent had tried both at about the same time. These data support the contention that tobacco use falls early in the sequence of drug use for young adoles- cents and therefore may be considered a "gateway' drug. Figure 8. Grade when respondents (high school seniors) first tried cigarettes, smokeless tobacco, alcohol, marijuana, and cocaine, among respondents who had ever used these substances by grade 12, Monitoring the Future Project, United States, 1986-1989 100 I- 60 2 8 k L 40 Grade 12 Cigarettes Smokeless tobacco Alcohol Marijuana Cocaine Source: Centers for Disease Control and Prevention, Office on Smoking and Health (unpublished data). 72 Epidemiology Grade 11 Grade 10 Grade 9 Grades 7-8 Grade 16 pr~wnting Tobacco Use Among Young People Table 24. Percent distribution of high school seniors (N [weighted] = 19,831), by grade in which they first (if ever) used cigarettes and alcohol, Monitoring the Future Project, United States, 1986-1989 Grade when respondent first tried alcohol Grade when respondent first tried Never Row cigarettes S6 7-a 9 10 11 12 used total $6 4.2 7.2 4.9 2.5 1.5 0.6 0.3 21.2 7-8 1.3 8.0 6.4 3.1 1.3 0.5 0.2 20.8 9 0.4 2.0 4.9 2.4 1.0 0.4 0.1 11.1 10 0.3 1.1 1.9 2.8 1.0 0.3 * 7.4 11 0.2 0.5 1.2 1.6 1.6 0.3 0.1 5.5 12 0.1 0.3 0.5 0.6 0.6 0.6 0.1 2.7 Never used 2.0 3.8 5.3 5.3 4.7 2.8 7.5 31.4 Source: Centers for Disease Control and Prevention, Office on Smoking and Health (unpublished data). * < 0.05. Note: Totals may not equal the sum of individual percentages because of rounding. Table 25. Percent distribution of high school seniors (N [weighted] = 20,657), by grade in which they first (if ever) tried cigarettes and marijuana, Monitoring the Future Project, United States, 1986-1989 Grade when respondent first tried cigarettes 5 6 Grade when respondent first tried marijuana 7-8 9 10 11 12 Never Row used total 56 2.0 4.5 3.3 2.2 1.4 0.8 6.2 20.3 7-8 0.3 4.1 4.4 2.9 1.5 0.8 5.8 19.8 9 0.1 0.5 2.5 2.3 1.2 0.6 3.5 10.7 10 0.1 0.2 0.5 1.7 1.4 0.5 2.6 6.9 11 * 0.1 0.3 0.4 1.3 0.6 2.5 5.2 12 * * 0.1 0.2 0.2 0.5 1.5 2.6 Never used 0.2 0.5 0.9 0.9 0.9 0.6 30.5 34.5 Source: Centers for Disease Control and Prevention, Office on Smoking and Health (unpublished data). *< 0.05. Note: Totals may not equal the sum of individual percentages because of rounding. Epidemiology 73 Surgeon General's Report Table 26. Percent distribution of high school seniors (N [weighted] = 21,007), by grade in which they first (if ever) used cigarettes and cocaine, Monitoring the Future Project, United States, 1986-1989 Grade when respondent first tried cocaine Grade when respondent first tried Never Row cigarettes 56 7-8 9 10 11 12 used total 16 0.1 0.4 0.9 1.2 1.4 0.9 15.4 20.3 7-8 * 0.2 0.6 1.1 1.3 0.9 15.6 19.7 9 * * 0.2 0.5 0.6 0.3 9.0 10.7 10 * * * 0.2 0.4 0.2 6.1 7.0 11 o ? o ? 0.2 0.2 4.8 5.2 12 o ? ? ? ? 0.1 .2.5 2.6 Never used * o 0.1 0.2 0.2 0.3 33.8 34.5 Source: Centers for Disease Control and Prevention, Office on Smoking and Health (unpublished data). o 0.05. < Note: Totals may not equal the sum of individual percentages because of rounding. Table 27. Percentage of high school students who used tobacco, by behaviors that contribute Lo unintentional and intentional injuries, Youth Risk Behavior Survey, United States, 1991 Current Current bY Current frequent smokeless Risk behavior Number cigarette use* cigarette use' cigarette use' tobacco us& Seat belt used Always Most the time/sometimes Rarely/ never Physical fighting' 0 times l-5 times 26times Weapon carrying** 0 days 2 1 day Attempted suicide' 0 times 11 time 2,908 60.2 17.8 6.8 13.5 5,651 70.1 26.3 11.4 17.6 3,548 80.6 40.3 21.8 26.5 6,864 63.9 20.3 8.1 13.9 4358 77.8 35.4 17.3 23.2 789 82.6 49.3 30.5 32.1 8,703 65.5 22.6 9.4 13.3 3,171 82.8 41.1 22.2 27.5 10,060 68.2 24.8 10.6 17.8 824 85.0 52.5 33.8 33.6 Sources: Centers for Disease Control and Prevention (CDC), Division of Adolescent and School Health (unpublished data); CDC, Office on Smoking and Health (unpublished data). *During the respondent's lifetime. `Cigarette use on 2 1 day during the 30 days preceding the survey. *Cigarette use on 2 20 days during the 30 days preceding the survey. sDuring the 30 days preceding the survey; includes chewing tobacco or snuff; males only. A When riding in a car driven by someone else. `During the 12 months preceding the survey. **During the 30 days preceding the survey; includes any weapon such as a gun, knife, or club. 74 Epidemiology preuen ting Tobacco Use Among Young People Cigarette use is most likely to precede use of other sub- stances and to be prevalent among users of other drugs. Cigarette Smoking and Other Health-Related Behaviors Available data on the relationships between ciga- rette smoking and other health-related behaviors are derived from cross-sectional studies and thus suggest that other behaviors may covary with adolescent smok- kg. Even if the direction of influence is not established, information on the extent of these relationships is useful for intervention, since such data may suggest a syn- drome of health-compromising behaviors that need to be considered together. Data from the 1991 YRBS indicate that high school students who reported practicing other selected health-. risk behaviors were more likely to be past-month or frequent smokers than were those who reported fewer selected health-risk behaviors. For example, students in the survey were more likely to be past-month or fre quent smokers if they rarely or never wore seat belts, had participated in a physical fight six or more times during the preceding year, had carried weapons one or more days during the preceding month, or had made one or more suicide attempts during the preceding year (Table 27). Students were also more likely to be past-month or frequent smokers if they had ever had sexual intercourse, had had sexual intercourse with four or more partners during their lifetime, or had not used a condom during their most recent sexual intercourse (Table 28). These relationships for sexual risk behaviors held for males and females, regardless of age (CDC, OSH, unpublished data). Lastly, students were more likely to be past- month or frequent smokers if they had not participated on any sponsored sports teams during the preceding year or if they had used steroids without a doctor's prescription (Table 29). Cigarette Smoking and Health Status Pregnancy and Smoking Data on maternal smoking status during pregnancy are recorded on birth certificates in 43 states and the District of Columbia (NCHS 1992b). ln these states, the overall maternal smoking prevalence was 20 percent in 1989. Maternal smoking among adolescent women Table 28. Percentage of high school students who used fobacco, by sexual risk behaviors, Youth Risk Behavior Survey, United States, 1991 , hY Current Current Current cigarette cigarette frequent smokeless Risk behavior Number use* use' cigarette usez tobacco uses Sexual intercoursed No 5,011 55.1 13.8 3.1 12.9 Yes 6,508 82.6 38.8 20.7 23.9 Number of sexual partners* l-3 4,048 81.0 33.8 15.4 23.2 24 2,443 85.4 47.9 30.3 24.9 Condom use1 No 2,494 86.4 46.2 27.5 23.8 Yes 2,091 79.3 36.0 18.5 26.6 Sources: Centers for Disease ControI and Prevention (CDC), Division of Adolescent and School Health (unpublished data); CDC, Office on Smoking and Health (unpublished data). * During the respondent's lifetime. ' Cigarette use on 11 day during the 30 days preceding the survey. $ Cigarette use on 2 20 days during the 30 days preceding the survey. 5 Any smokeless tobacco use, including chewing tobacco or snuff, during the 30 days preceding the survey; males only. * During the respondent's lifetime. 7 During last sexual intercourse, among students who had sexual intercourse during the 3 months preceding the survey. Epidemiology 75 Surgeon General's Report Table 29. Percentage of high school students who used tobacco, by participation on sports teams and steroid use, Youth Risk Behavior Survey, United States, 1991 Category Number Any Current Current Current cigarette cigarette frequent smokeless use* use+ cigarette us& tobacco uses Participation on sports team+ Total 0 teams 2 1 team Female 0 teams 2 1 team Male 0 teams 2 1 team Steroid useq Total 0 times 2 1 time Female 0 times 2 1 time Male 0 times 2 1 time 5,738 73.6 31.3 6.6 6,429 67.2 24.3 13.5 3,608 72:O 29.0 0.7 2,635 66.3 24.8 2.1 2,125 76.1 34.8 15.5 3,794 67.8 23.9 21.0 11,868 69.7 26.8 12.1 9.7 382 87.2 54.8 35.7 38.7 6,164 69.3 26.9 12.2 1.1 116 88.5 61.8 29.9 16.5 5,700 265 70.0 26.6 12.0 18.1 86.8 52.6 27.0 44.6 Source: Centers for Disease Control and Prevention, Division of Adolescent and School Health (unpublished data). *During the respondent's lifetime. + Cigarette use on 2 1 day during the 30 days preceding the survey. `Cigarette use on 120 days during the 30 days preceding the survey. 5During the 30 days preceding the survey; includes chewing tobacco or snuff. *During the 12 months preceding the survey; includes sports teams sponsored by school and other organizations. TDuring the respondent's lifetime, without a doctor's prescription. 76 EpidemioIogy preventing Tobacco Use Among Young People (under 20 years old) was highest among women aged 18 and 19 (24 percent) and lowest among women younger &an 15 years of age (8 percent) (Table 30). White non- Hispanic adolescent mothers were more likely to have smoked during pregnancy than white non-Hispanic mothers 20 through 49 years old, Black non-Hispanic adolescent mothers were less likely to have smoked than those 20 through 49 years old; Hispanic adolescent moth- ers were about as likely as older Hispanic mothers to have smoked. Among the mothers who smoked during pregnancy, about 23 percent of those younger than 15 years of age smoked more than 10 cigarettes per day; 34 percent of mothers 15 through 19 years old, and 44 percent of mothers 20 through 49 years old smoked more than 10 cigarettes per day during the pregnancy (NCHS 1992b). Self-Reported Indicators of Health Status Among Smokers The MTFl? collected data on self-reported indica- tors of health status among the nation's high school seniors. A five-category scale of lifetime smoking history was constructed from questions on lifetime smoking and on the grade in which the respondent began smoking daily (Table 31). Nine measures of health status were analyzed in terms of lifetime smoking history. Adjusted odds ratios were calculated by regressing the logit-trans- formed prevalence of each health measure over the prior year on the variable for lifetime smoking history and Qn the covariates of current marijuana use, lifetime cocaine use, parental education, and time (Hosmer and.L.emeshow 1989). Alcohol use was also included as a covariate for the measures of staying at home because of not feeling well and of overall physical health. Current smokers were more likely than never smokers to report all of the symptoms or indicators listed. A trend test (using the linear contrast of the estimated regression coefficients for smoking history [Miller 19861) revealed that these adolescent smokers were more likely than never smok- ers to experience all but two of the health status measures (e.g., sinus congestion and sore throat). Self-Reported Indicators of Nicotine Addiction Among Smokers The research of McNeil1 (McNeil1 et al. 1986; McNeill, Jarvis, West 1987; McNeill 1991) has demon- strated the presence of nicotine addiction in young smok- ers (11 through 16 years old) in Great Britain. A majority of these young smokers experienced withdrawal symp tams during abstinence or had some difficulty quitting (McNeilI et al. 1986; McNeill, Jarvis, West 1987). The 1991 NHSDA asked 12- through 18-year-olds questions that probed various components `of nicotine addiction (USDHHS 1988b). Current smokers who had smoked at least 100 cigarettes in their lifetime were the most likely of adolescent smokers to report having experienced sev- eral indicators of nicotine addiction Crable 32). Four of every five of these heavier smokers who tried to cut down on cigarettes during the previous 12 months had failed. Seventy percent felt that they needed or were dependent on cigarettes. Persons who had smoked at least 100 cigarettes in their lifetime but none in the last month were the next most likely to report that they felt dependent on cigarettes and that they had experienced withdrawal during the previous 12 months. These persons were more likely to have become regular smokers than were those who had not yet smoked 100 cigarettes. Though these respon- dents were more likely to show signs of'addiction, they were evidently able to discontinue smoking for at least one month-a finding consistent with the observation that less-addicted smokers are more able to quit (USDHHS 1988b). Respondents who had not smoked 100 cigarettes by the time they were surveyed appeared less likely to become addicted to nicotine than those who had smoked at least 100 cigarettes. Table 30. Cigarette smoking prevalence (%) during pregnancy among mothers of live-born infants, by age and race/Hispanic origin, 43 states and the District of Columbia, 1989 Age (years) Race/Hispanic origin c 15 Overall 7.7 White, non-Hispanic 21.2 Black, non-Hispanic 2.7 Hispanic 5.9 Source: National Center for Health Statistics (1992b). 15-17 18 -19 20- 49 19.0 23.9 19.1 32.1 33.3 20.5 6.2 10.4 20.2 7.5 8.7 8.0 Epidemiology 77 Surgeon General's Report Table 31. Adjusted odds ratios* (and 95% confidence intervals) for symptoms of diseases and smoking status among high school seniors who have smoked occasionally or regularly, Monitoring the Future Project, United States, 1982-1989 Self-reported symptom/ indicator+ Have smoked occasionally, but not regularly Smoked regularly at one time, but not in the past 30 days Smoke regularly now, began daily smoking in grades 10-12 Smoke regularly now, began daily smoking by grade 9 Shortness of breath when not exercising 1;38 (1.24,1.52) Chest cold 1.34 (1.23,1.46) Sinus conges- tion, runny nose, sneezing 1.31 (1.20,1.44) Coughing spells 1.33 (1.24, 1.43) Cough with phlegm or blood 1.42 (1.28,1.56) Wheezing or gasping 1.41 (1.26, 1.48) Sore throat or hoarse voice 1.36 (1.26, 1.48) Stayed home most or all of day because not feeling wellt 1.43 (1.31,1.55) Overall physical healthts 1.47 (1.32,1.63) 1.90 (1.56,2.31) 1.34 (1.13,1.60) 0.99 (0.83,1.19) 1.28 (1.11, 1.48) 1.73 ( 1.44,2.09) 2.45 <1.9'9,3.01) 1.07 (0.92, 1.26) 1.38 (1.17,1.62) 2.39 (1.98,2.90) 2.32 (2.03,2.64) 1.53 (1.35, 1.73) 1.17 (1.02,1.34) 2.04 (1.83,2.27) 2.31 (2.02,2.63) 2.36 (2.06,2.70) 1.34 ( 1.19, 1.52) 1.53 (1.35,1.73) 1.98 (1.72,2.28) 2.72 (2.40,3.08) 1.72 (1.52,1.93) 1.19 (1.05,1.35) 2.20 ( 1.98,2.45) 2.32 (2.04.2.64) 2.57 (2.25,2.95) 1.17 (1.04, 1.32) 1.56 (1.39,1.76) 2.08 (1.81,2.38) Source: Centers for Disease Control and Prevention, Office on Smoking and Health (unpublished data). *Adjusted for past-month marijuana use, lifetime cocaine use, parental education, and time. Odds ratios are relative to those for seniors who had either never smoked cigarettes or had smoked cigarettes once or twice only. `Occurrence during the previous 30 days, with the exeption of overall physical health. *Also adjusted for past-month alcohol use. Qdds ratios based on the percentage who reported that their health was poorer than average during the preceding year. 78 Epidemiology prLenting Tobacco Use Among Young People Table 32. Self-reported indicators of nicotine addiction among 12-M-year-olds (N = 1,589), by smoking history, National Household Surveys on Drug Abuse, United States, 1991 Smoking history* Indicator' Have smoked Have smoked Have smoked Have smoked l-99 2 100 l-99 2 100 cigarettes, cigarettes, cigarettes cigarettes but none in but none in and smoked in and smoked in past month past month past month past month (o/o) (%I,) (%Jo) (%) - Tried to cut down on use of cigarettes 43.7 Unable to cut down on use of cigarettes* 46.9 72.2 40.4 59.5 81.2 44.9 73.4 Felt need to have more cigarettes to get the same effect Felt need to have cigarettes or felt dependent on cigarettes Felt sick because of stopping or cutting down on cigarettes* 10.9 14.2 12.2 27.1 12.2 37.2 16.2 70.1 15.9 24.9 14.1 37.4 Source: Centers for Disease Control and Prevention, Office on Smoking and Health (unpublished data). *Among people who smoked cigarettes at all in the past 12 months. `Occurrence during the past 12 months. *Analysis limited to people who tried to cut down on cigarettes during the last 12 months. Smokeless Tobacco Use Among Young People in the United States Recent Patterns of Smokeless Tobacco Use Ever Use of Smokeless Tobacco The overall national estimates for adolescents who had tried smokeless tobacco were 18 percent for 12- through Wyear-olds in the 1989 TAPS, 13 percent for the same age group in the 1991 NHSDA, and 32 percent for high school seniors surveyed by the MTFP in 1992 (Table 33). In all three surveys, males were much more likely than females to have tried smokeless tobacco. White males were more likely than any other subgroup to have tied this product. The prevalence of adolescents who had used smoke- less tobacco increased with increasing age. Twenty- eight percent of 17- and B-year-old TAPS respondents, 21 percent of 17- and B-year-old NHSDA respondents, and 32 percent of high school seniors in the 1992 MTFP survey reported that they had tried smokeless tobacco. Adolescents in the northeast region of the United States were less likely than those in the other regions to have tried smokeless tobacco. Current Use of Smokeless Tobacco Available data suggest that there was an increase in the use of smokeless tobacco among adolescents between 1970 and the mid-1980s. The prevalence of chewing tobacco use was 1.2 percent among 17- through 19-year-old males in the 1970 THIS KJSDHHS 1986, 1989b), 3.0 percent among 16- through 19-year-old males in the 1985 Current Population Survey (Marcus et al. 1989; USDHHS 19861, and 5.3 percent among 17- through 19-year-old males in the 1986 Adult Use of Tobacco Epidemiology 79 Surgeon Generd's Reporf Table 33. Percentage of young people who have ever used smokeless tobacco, by gender, race/Hispanic origin, age/grade, and region, Teenage Attitudes and Practices Survey (TAPS), National Household Surveys on Drug Abuse (NHSDA), Monitoring the Future Project WTFP), United States, 1989,1991,19!I2 Characteristic TAPS* NHSDAt MTFPS Overall 18.4 13.2 32.4 Gender Male Female 31.3 4.4 22.3 3.5 53.7 12.1 Race/Hispanic origin White, non-Hispanic Male Female Black, non-Hispanic Male Female Hispanic Male Female 22.4 16.6 38.2 38.6 28.4 61.6 4.8 4.4 15.2 7.6 4.5 10.7 11.9 6.7 18.0 3.1 2.1 4.9 8.1 4.8 NA* 13.4 8.8 NA 2.3 0.5 NA Age/grade 12-14 years 15-16 years 17-18 years 8th grade 10th grade 12th grade Region Northeast North Central South West 9.6 6.5 20.8 15.0 28.2 20.9 20.7 26.6 32.4 14.0 9.0 25.3 19.7 14.0 38.6 21.4 13.9 31.5 15.8 14.5 32.0 Sources: 1989 TAPS: Centers for Disease Control and Prevention (CDC), Office on Smoking and Health (OSH) (unpub- lished data); 1991 NHSDA: CDC, OSH (unpublished data); 1992 MT'FP: Johnston, O'Malley, Bachman (in press); Institute for Social Research, University of Michigan (unpublished data). *1989 TARS, aged 12-18 years. Based on response to the question, "Have you ever tried using chewing tobacco or snuff?" `1991 NHSDA, aged 12-18 years. Based on response to the question, "When was the most recent time you used chewing tobacco or snuff or other smokeless tobacco? ("Never used smokeless tobacco in lifetime" was a preceded response.) $1992 MTFP survey of high school seniors. Based on response to the question, "Have you ever taken or used smokeless tobacco (snuff, plug, dipping tobacco, chewing tobacco) ?" Respondents who reported that they had taken or used smoke- less tobacco at least once or twice were classified as ever users. _With the exception of data for 8th- and IOth-grade students, all other data points for the MTFP surveys reflect estimates for high school seniors. *NA = Not available. 80 Epidemiology prn~enfing Tobacco Use Among Young People Survey (AUTS) CUSDHHS 1989b). The same surveys indicated that the prevalence of snuff use was 0.3 percent among 17-through 19-year-old males in 1970,2.9 percent among 16 through 19-year-old males in 1985, and 5.3 percent among 17- through 1 g-year-old males in 1986. In the 1986-1989 MTFP surveys, high school se- niors' past-month use of smokeless tobacco declined slightly for all respondents (from 12 to 8 percent), for whites (from 13 to 10 percent), and for males (from 22 to 16 percent) (Bachman, Johnston, O'MaIIey 1987, 1991; Johnston, Bachman, O'MalIey 1991, 1992). In the 1992 MTFP survey, however, past-month use of smokeless tobacco was 11 percent for all respondents, 14 percent for whites, and 21 percent for males (ISR, University of Michigan, unpublished data). In the NHSDA, the preva- lence of past-month use of smokeless tobacco among 12- through 17-year-old males was 6.6 percent in 1988 and 5.3 percent in 1991 (USDHHS 1989a, 1992a). In the same survey, use of smokeless tobacco in the past year was estimated to be 11.1 percent in 1985,7.0 percent in 1988, 6.1 percent in 1990, and 6.1 percent in 1991. A parallel decline has been reported among young adults (18 through 25 years old): the prevalence of past-year use of smokeless tobacco in this group was 11 .l percent in 1985, 8.9 percent in 1988,9.2 percent in 1990, and 8.7 percent in 1991 (USDHHS 1988a, 1989a, 1991a, 1992a). The reduction in the late 1980s may be attributed to increased awareness resulting from several events: (1) the much-publicized Sean Marsee case, in which a star high school athlete who used snuff died of oral cancer (Fincher 1985); (2) the 1986 convening of a major national conference on smokeless tobacco use and the 1986 release of a report by the Advisory Committee to the Surgeon General on smokeless tobacco (Journal of the American Medical Association 1986; USDHHS 1986); (3) the intro- duction in 1986 of health warnings on smokeless tobacco packages and advertising; and (4) the enactment in 1986 of a ban on the advertising of smokeless tobacco prod- ucts through the electronic media (USDHHS 1989b, 1992b). The overall national prevalence estimates for cur- rent smokeless tobacco use (within the 30 days preced- ing the survey) were 3 percent for past-month users among persons 12 through 18 years old surveyed in the 1991 NHSDA (reflecting about 800,000 users), 11 percent for high school seniors in the 1992 MTFP survey, and 11 percent for students in grades 9-12 in the 1991 YRBS (Table 34). Current use was substantially more preva- lent among males than females; 6 percent of the males in the NHSDA and 20 percent of the males in the other two surveys reported current use, whereas only about 1 per- cent of the females in the three surveys reported current use. Smokeless tobacco use was highest among white males; Hispanic males had the next highest prevalence, and black males had the lowest. Although reliable na- tional data are not currently available on smokeIess to bacco use among American Indian and Alaskan Native adolescents, local surveys have reported very high preva- lence (e.g., CDC 1987, 1988; Schinke et al. 1987; HaII and Dexter 1988; see aIso "Sociodemographic Factors in the Initiation of Smokeless Tobacco Use" in Chapter 4). Smokeless tobacco use increased with increasing age in the NHSDA survey of 12- through l&year-olds and by grade in the 1992 MTFP survey, but did not change appreciably among students in the four high school grades surveyed by the YRBS. Individual YRBS surveys conducted in several state and local communities found that male high school stu- dents were far more likely than females to use smokeless tobacco (Table 35); nonetheless, smokeless tobacco was used by as much as 10 percent of female respondents in a given state survey. In some states (Alabama, Idaho, South Dakota, Colorado, Wyoming, and Montana), males were as likely to report current smokeless tobacco use as they were to report current cigarette use (see Table 3). The 1992 MTFP survey gathered data on the fre- quency of smokeless tobacco use among approximately 2,600 high school seniors (ISR, University of Michigan, unpublished data). Users were classified according to the number of days they had used smokeless tobacco over a period of 30 days. Thirty-eight percent of male users and 20 percent of female users reported that they had used smokeless tobacco at least once every day. Seventy percent of the female users reported that they had used the product less than once each week. Thirty- nine percent of white users and 12 percent of black users reported daily use of smokeless tobacco. Almost 60 per- cent of the black users reported that they had used the product less than once each week. Among past-month users, 46 percent of those living in the West and 43 percent of those from the South had used smokeless tobacco at least once each day. Thirty-three percent of users who lived in the north-central and 22 percent from the northeast United States used smokeless tobacco on a daily basis. Use of Smokeless Tobacco and Cigarettes As was shown in Table 23,43 percent of male high school seniors who used smokeless tobacco also smoked cigarettes. Tobacco, either in the form of cigarettes or smokeless tobacco, was used by 15 percent of 12- through 18year-olds in the 1991 NHSDA, 32 percent of high school students in the 1991 YRBS, and 33 percent of high school seniors in the 1992 MTFP (Table 36). Males were substantially more likely than females to use tobacco. Regardless of gender, the prevalence of tobacco use for Epidemiology 81 Surgeon General's Report Table 34. Percentage of young people who currently (within the past 30 days) use smokeless tobacco, by gender, race/Hispanic origin, age/grade, and region, National Household Surveys on Drug Abuse (NHSDA), Monitoring the Future Project (MTFP), Youth Risk Behavior Survey (YRBS), United States, 1991,1992 Characteristic NHSDA* MTFPti YRBSS Overall Gender Male Female Race/Hispanic origin White, non-Hispanic Male Female Black, non-Hispanic Male Female Hispanic Male Female Age/ grade 12-14 years 15-16 years 17-18 years 8th grade 9th grade 10th grade 11 th grade 12th grade Region Northeast North Central South West 3.4 6.0 20.8 19.2 0.6 2.0 1.3 4.4 13.5 13.0 8.1 23.9 23.6 0.5 2.5 1.4 0.7 2.5 2.1 0.5 5.2 3.6 0.8 0.2 0.7 1.2 NA* 5.5 2.1 NA 10.7 0.3 NA 0.6 11.4 1.5 3.6 5.9 7.0 0.8 8.2 8.8 3.9 12.3 13.3 4.0 12.5 8.6 3.9 11.1 10.5 9.6 11.4 10.5 9.0 10.1 12.1 10.7 Sources: 1991 NHSDA: Centers for Disease Control and Prevention (CDC), Office on Smoking and Health (unpublished data); 1992 MTFPz Johnston, O'Malley, Bachman (in press); Institute for Social Research, University of Michigan (unpub- lished data); 1991 YRBS: CDC (1992~); CDC, Division of Adolescent and School Health (unpublished data). *1991 NHSDA, aged 12-18 years. Based on response to the question, `When was the most recent time you used chewing tobacco or snuff or other smokeless tobacco?" `1992 MTFP survey of high school seniors. Based on response to the question, "How frequently have you taken smokeless tobacco during the past 30 days?" twith the exception of data for 8th- and IOth-grade students, all other data points for the MTFP survey reflect estimates for high school seniors. "1991 YRBS, grades 9-12. Based on response to the question, "During the past 30 days, did you use chewing tobacco, such as Redman, Levi Garrett, or Beechnut, or snuff, such as Skoal, Skoal Bandits, or Copenhagen?" ANA = Not available. 82 Epidemiology preventing Tobacco Use Among Young People Table 35. Percentage of high school students who use smokeless tobacco, by gender, Youth Risk Behavior Surveys, United States and selected U.S. sites, 1991 Smokeless tobacco use* Site Weighted data National survey Female 1 Male Total 19 10 State surveys Alabama 2 31 16 Georgia 2 22 12 3 24 14 Idaho 2 26 14 Nebraska 16 New Mexico 4 27 New York' 2 19 11 0 5 2 Puerto Rico* South Carolina 2 20 11 South Dakota 10 29 20 7 Utah 2 12 Local surveys Chicago 2 5 3 Dallas 1 7 4 Fort Lauderdale 1 9 4 1 6 3 Jersey City Mimi 1 6 3 2 6 4 Philadelphia San Diego 1 7 4 Unweighted data5 State surveys Colorado' District of Columbia* Hawaii Montana New Hampshire New Jersey' Oregon Pennsylvania+ Tennessee Wisconsin Wyoming Local surveys Boston New York City San Francisco 6 2 2 7 4 2 5 2 1 3 5 1 5 3 1 5 3 2 6 4 32 19 5 4 14 8 33 20 22 13 14 7 28 16 29 16 34 17 19 11 31 19 Source: Centers for Disease Control (1992d). *Respondents used chewing tobacco or snuff on 1 or more of the 30 days preceding the survey. `Surveys did not include students from the largest city. tCategorized as a state for funding purposes. gFour&n sites had overall response rates below 60 percent or had unavailable documentation; weighted estim&s were not reported. Epidemiology 83 Surgeon GeneraI's Report Table 36. Percentage of young people who currently (within the past 30 days) use cigarettes and/or smokeless tobacco, by gender, race/Hispanic origin, region, and age/grade, National Household Surveys on Drug Abuse (NHSDA), Monitoring the Future Project (MTFP), Youth Risk Behavior Survey (YRBS), United States, 1991,1992 Characteristic NHSDA' MTFP+ YRBS' Overall Gender Male Female Race/Hispanic origin5 White, non-Hispanic Male Female Black, non-Hispanic Male Female Hispanic Male Female Age/grade 12-14 years 15-16 years 17-18 years 8th grade 9th grade 10th grade 11 th grade 12th grade Region Northeast North Central South West 15.1 33.2 31.8 17.1 38.8 35.8 13.0 27.3 27.6 17.9 38.4 36.2 20.3 43.0 40.0 15.4 33.3 32.0 6.0 8.8 13.7 6.6 14.3 16.0 5.4 4.5 11.6 10.9 NA_ 28.1 10.8 NA 33.6 10.9 NA 23.1 5.1 16.2 28.5 20.5 28.2 35.1 17.0 37.7 14.5 30.3 14.2 30.0 27.6 33.2 26.7 29.6 36.3 34.7 40.8 28.8 27.6 Sources: 1991 NHSDA: Centers for Disease Control and Prevention (CDC), Office on Smoking and Health (unpublished data); 1992 MTFP: Johnston, O'Malley, Bachman (in press); Institute for Social Research, University of Michigan (unpub- lished data); 1991 YRBS: CDC, Division of Adolescent and School Health (unpublished data). *1991 NHSDA, aged 12-18 years. Based on responses to the questions, "When was the most recent time you smoked a cigarette?" and "When was the most recent time you used chewing tobacco or snuff or other smokeless tobacco?" `1992 MTFP surveys of high school seniors. Based on responses to the questions, "How frequently have you smoked cigarettes during the past 30 days?" and "How frequently have you taken smokeless tobacco during the past 30 days?" t1991 YRBS, grades 9-12. Based on responses to the questions, "During the past 30 days, on how many days did you smoke cigarettes?" and "During the past 30 days, did you use chewing tobacco, such as Redman, Levi Garrett, or Beechnut, or snuff, such as Skoal, Skoal Bandits, or Copenhagen?" _NA = Not available. 84 Epidemiology prL~,enting Tobacco USZ Among Young People &te adolescents was higher than for Hispanics and b@S. TObXCO Use hCreased with increasing age and ts~as most common in the north-central region of the un&cI states. sociodemographic Risk Factors for Smokeless Tobacco Use Current use of smokeless tobacco among male high school seniors varied according to several hodemographic indicators, as shown by the 1986-1989 MTFI' surveys (N [weighted] = 5,277). The prevalence of current smokeless tobacco use was 28 percent among those who lived alone, 29 percent among those living in father-only households, 16 percent among those living in mother-only households, and 20 percent among those living with both parents. Current use was more common among male seniors living on farms (34 percent) and in the country (31 percent> than among those living in medium- sized to very large cities or suburbs (11 to 17 percent). The prevalence of current use was greater among students who rated their academic performance as average (25 percent) or below average (26 percent) than among those whoratedtheirperformanceasslightlyaboveaverage(18 percent) or far above average (16 percent). Smokeless tobacco use was more common among male seniors who planned to enter the armed forces after high school than among those who did not have such plans (23 vs. 19 percent). The self-reported importance of religion did not affect the prevalence of smokeless tobacco use among these MTFP seniors. Grade When Smokeless Tobacco Use Begins' The grade distribution for which MTFP seniors reported first trying smokeless tobacco was more similar to that reported for cigarettes than it was for those re- ported for alcohol, marijuana, and cocaine (Figure 8). Among seniors who had used smokeless tobacco, 23 percent had first done so by grade six, 53 percent by grade eight, and 73 percent by the ninth grade. Attempts to Quit Using Smokeless Tobacco Twenty-two percent of the male high school seniors in the 1986-1989 MTFP who had regularly used smokeless tobacco reported that they had not used the product during the 30 days preceding the survey. In the 1986-1989 TAPS, 12- through l&year- olds who regularly used smokeless tobacco were asked to report the number of times they had tried to quit. Nineteen percent of males and 14 percent of females reported never making a quit attempt. Thirty- three percent of males and 72 percent of females had made one attempt to quit, 27 percent of males and 14 percent of females had tried quitting two or three times, and 21 percent of males and no females had tried to quit four or more times (1989 TAPS, CDC, OSH, unpublished data). Smokeless Tobacco Brand Preference TAPS also asked those who had regularly used smokeless tobacco what brand they usually bought. Among males in this subgroup (N = 300), 38 percent usually bought Copenhagen, 26 percent purchased Skoal or Skoal Bandits, 9 percent purchased Redman, 6 percent bought Levi Garrett, 2 percent purchased Beechnut, and 19 percent purchased other smokeless tobacco brands (1989 TAPS, CDC, OSH, unpublished data). Trends in Perceived Health Risks of Smokeless Tobacco Use High school seniors in the MTFP were asked, "How much do you think people risk harming themselves (physically or in other ways) if they use smokeless tobacco regularly (chewing tobacco, plug, dipping tobacco, snuff)?" Overall in 1991,37 percent reported that great risk of harm is associated with smokeless tobacco use (ISR, University of Michigan, unpublished data); more females (43 percent) than males (32 percent) and more blacks (44 percent) than whites (36 percent) were of this opinion. Western respondents more frequently held this belief (43 percent) than respondents in the South (37 percent), the Northeast (36 percent), and the north-cen- tral United States (35 percent). Respondents who planned to attend college for four years were more likely to report this belief than those without college plans (39 vs. 33 percent). When the overall percentage of seniors in the 1986 1989 MTFP who believed that great risk is associated with smokeless tobacco use is plotted against the percentage of seniors who had used smokeless tobacco, the trends of these percentages are inversely related (Figure 9). between 1986 and 1988, the percentage of seniors who believed that great risk is associated with smokeless tobacco use increased from 26 to 33 percent. between 1988 and 1989, this percentage remained rela- tively stable. The percentage of seniors who had used smokeless tobacco increased slightly between 1986 (31 percent) and 1987 (32 percent) and decreased by 1989 (29 percent). This finding is similar to that observed for cigarette smoking (Figure 5). In the 1989 TAPS, 94 percent of 12- through 1& year-old males reported that use of chewing tobacco and snuff can cause cancer. Ninety-three percent of those males who had never used smokeless tobacco and 96 percent of those who had regularly used the product endorsed that statement (Allen et al. 1993). Epidemiology 85 Surgeon General's Report Figure 9. Trends in the percentage of high school seniors who believe that regular use of smokeless tobacco is a serious health risk and who have ever used smokeless tobacco, Monitoring the Future Project, United States, 1986-1989 40 38 36 32 E 8 30 $ CI 28 26 24 22 20 - Ever use 1986 1987 Year 1988 1989 Sources: Bachman, Johnston, O'Malley (1987,1991); Johnston, Bachman, O'Malley (1991,1992). Smokeless Tobacco Use and Other Drug Use Prevalence of Smokeless Tobacco Use and Other Drug Use The majority of male high school seniors in the 1986-1989 MTFP who used alcohol, marijuana, cocaine, or inhalants did not use smokeless tobacco (Table 37). Smokeless tobacco use, however, was from 1 .S to 3.9 times higher among users of these drugs than among nonusers. Most notably, 90 percent of smokeless tobacco users were also alcohol drinkers. Almost one-third (31 percent) of smokeless tobacco users also used marijuana, 7 percent used cocaine, and 5 percent used inhalants. The preva- lence of other drug use was from 1.4 to 1.9 times greater among smokeless tobacco users than nonusers. Grade When Use of Smokeless Tobacco and Cigarettes Begins In the 1986-1989 MTFP, 28 percent of all males had never tried cigarettes or smokeless tobacco by the 12th grade; 44 percent had tried both; 18 percent had tried cigarettes but not smokeless tobacco; and 9 percent had tried smokeless tobacco but not cigarettes (Table 38). Of those male seniors who had tried both, 37 percent had tried cigarettes before smokeless tobacco, 24 percent had tried smokeless tobacco before cigarettes, and 40 percent had first tried both at about the same time. Smokeless Tobacco Use and Other Health- Related Behaviors In the 1991 YRBS, male high school students were more likely to report past-month use of smokeless tobacco if they rarely or never wore seat belts, were frequently involved in physical fights, carried weapons during one or more of the preceding 30 days, and had made one or more suicide attempts during the preceding 12 months (Table 27). These students were also more likely to currently use smokeless tobacco if they had ever had sexual intercourse (Table 28). Smokeless tobacco use did not vary appreciably (compared with cigarette smoking) 86 Epidemiology p~mnting Tobacco Use Among Young PeopJe Table 37. Prevalence (o/o) of smokeless tobacco use among users of other drugs and prevalence of other drug use among smokeless tobacco users,+ male high school seniors, Monitoring the Future Project, United States, 1986 -1989 Other drugs Prevalence of Prevalence of Prevalence of Prevalence of smokeless smokeless other drug use other drug use tobacco use tobacco use among smoke- among nonusers among users of among nonusers .less tobacco of smokeless other drugs of other drugs users tobacco Alcohol 26.3 6.8 89.6 Marijuana 27.6 17.6 30.9 Cocaine+ 28.7 19.6 7.4 Inhalants* 32.3 19.6 5.0 Source: Centers for Disease Control and Prevention, Office on Smoking and Health (unpublished data). `Any use of smokeless tobacco or other drugs during the past month. `Includes "coke, " "crack," and "rock." t Glue, aerosols, laughing gas, etc. 63.8 20.0 4.6 2.6 Table 38. Percent distribution of male high school seniors (N [weighted] = 4,254), by grade in which they first used cigarettes and smokeless tobacco (used in the past 30 days), Monitoring the Future Project (MTFP), United States, 1986-1989 Grade when respondent first tried smokeless tobacco Grade when respondent first tried cigarettes <6 7-8 9 10 11 12 Never Row used total 56 7.1 4.9 2.3 1.4 0.7 0.3 5.8 22.4 7-8 2.1 5.8 2.5 1.3 0.8 0.3 4.7 17.5 9 1.3 2.0 2.3 0.9 0.4 0.2 3.2 10.3 10 0.6 0.7 1.0 1.5 0.2 0.1 2.3 6.4 11 0.1 0.5 0.7 0.5 0.5 0.1 1.5 3.9 12 + 0.3 0.2 0.1 0.1 0.3 0.9 1.9 Never used 2.0 2.7 1.9 1.1 1.3 0.2 28.3 37.6 Column total 13.3 16.9 11.0 6.9 4.0 1.4 46.7 100.0 Source: Centers for Disease Control and Prevention, Office on Smoking and Health (unpublished data). o < 0.05. Note: Totals may not equal the sum of individual percentages because of rounding. by how many lifetime sexual partners these males had had or by whether they had used a condom during their most recent sexual intercourse. Lastly, students were consistently more likely to currently use smokeless to- bacco if they had participated on a sponsored sports team (Table 29). This finding is opposite to that found for cigarette smoking and sports. Smokeless tobacco use was also more likely among students who had used steroids without a doctor's prescription. Epidemiology 87 Surgeon General's Report Conclusions 1. 2. 3. Tobacco use primarily begins in early adolescence, typically by age 16; almost all first use occurs before the tune of high school graduation. Smoking prevalence among adolescents declined sharply in the 1970s but the decline slowed signifi- cantly in the 1980s. At least 3.1 million adolescents and 25 percent of 17- and Wyear-olds are current smokers. 4. 5. Although current smoking prevalence among fe- male adolescents began exceeding that among males by the mid- to late-1970s both sexes arenow equally likely to smoke. Males are significantly more likely than females to use smokeless tobacco. Nationally, white adolescents are more likely to use all forms of tobacco than are blacks and Hispanics. The decline in the prevalence of cigarette smoking among black adolescents is noteworthy. Many adolescent smokers are addicted to cigarettes; these young smokers report withdrawal symptoms similar to those reported by adults. Tobacco use in adolescence is associated with a range of healthcompromising behaviors, including being involved in fights, carrying .weapons, engaging in higher-risk sexual behavior, and using alcohol and other drugs. 88 EpidemioIogy praenting Tobacco Use Among Young People Chapter 4: Psychosocial Risk Factors for Initiating Tobacco Use Introduction Tobacco use begins primarily through the dynamic interplay of sociodemographic, environ- mental, behavioral, and personal factors. These psychosocial risk factors increase a person's chances both of beginning to use tobacco and of experiencing the immediate and long-term health problems associated with tobacco use. Young people (aged 10 through 18 years) are particularly affected by psychosocial factors and are thus particularly vulnerable to adopting tobacco use. Since psychosocial risk factors are the initial influences in the causal chain that leads to tobacco-related health consequences, primary prevention efforts to re- duce smoking prevalence must take these influences into account. Psychosocial risk factors for tobacco use can be viewed as a continuum of proximal to distal factors. Personal and behavioral factors that directly affect an individual's choice to use tobacco (when a cigarette is offered, for example) areconsidered proximal risk factors, whereas environmental and so&demographic factors (such as billboard advertising and household income) that indirectly affect the accessibility or acceptability of tobacco use are classified as distal factors. Proximal factors are considered more immediate to a person's decision to use tobacco than distal factors. Still, as is shown in Chapter 5 (see "Research on the Effects of Cigarette Advertising and Promotional Activities on Young People"), distal factors acquire potency if they are pervasive and provide consistent, repetitive messages across multiple channels. Distal factors are also powerful because, over time, they affect proximal factors as these influences become interpreted and internalized, particu- larlyamongadolescentsastheytrytoshapeamatureself- identity. This review examines each of these sets of risk factors to provide a comprehensive view of the anteced- ents of tobacco use, first for cigarette smoking, then for smokeless tobacco use. The database for this review includes research studies that have been published pri- marily in peer-refereed journals or books during the past 15 years. Results from these studies were grouped according to psychosocial risk factor, and conclusions were based on the availability and conclusiveness of the evidence for a given risk factor. Table 1 summarizes the major psychosocial risk factors examined in this chapter and in Chapter 5. Table 1. Psychosocial risk factors in the initiation of tobacco use among adolescents Smokeless Risk factors Smoking tobacco Sociodemographic factors Low socioeconomic status X Developmental stage X X Male gender X Environmental factors Accessibility X X Advertising X X Parental use Sibling use X Peer use X X Normative expectations X X Social support X Behavioral factors Academic achievement X X Other problem behaviors x X Constructive behaviors X Behavioral skills X Intentions X X Experimentation X X Personal factors Knowledge of consequences X Functional meanings X X Subjective expected utility x Self-esteem/self-image X X Self-efficacy X Personality factors X Psychological well-being x Psychosocial Risk Factors 89 Surgeon GeneraIs Report Initiation of Cigarette Smoking Introduction Early public health efforts to prevent smoking among adolescents were largely informed by health- related and demographic findings from research stimu- lated by the landmark 1964 Surgeon General's report on smoking and health (Public Health Service 1964; Chassin, Presson, Sherman 1990). By the mid-1970s, the ineffectiveness of these attempts to reduce rates of smok- ing onset among adolescents further stimulated research into what motivates young people to begin smoking (Thompson 1978). Significant support for such research was provided by the National Clearinghouse for Smok- ing and Health, the National Institutes of Health, the National Institute on Drug Abuse (NIDA), and various private health organizations, including the American Lung Association, the American Cancer Society, and the American Heart Association. The application of psychosocial theories to the area of adolescent smoking behavior provided a major break- through in the understanding of smoking initiation and development, pioneered by the conceptual and pilot work of Leventhal(19681, Bandura (1977), Evans et al. (19781, McAlister, Perry, and Maccoby (1979), and McGuire (1984). Rather than view cigarette smoking as a health behavior, these researchers examined smoking as a so- cial behavior, with social causes, functions, and rein- forcements. Although this early work involved mostly correlational research, such as examining the relation- ship between parental smoking and children's smoking behavior, research became increasingly theory-driven, longitudinal, prospective, and multivariate during the 1980s (Chassin, Presson, Sherman 1990). Conrad, Flay, and Hill (1992) recently reviewed 27 prospective studies on smoking initiation published since 1980 (see Table 2 for characteristics of these studies). The large number of such methodologically sophisticated studies provides a sufficient base of knowledge to begin drawing conclu- sions about the relative importance of a variety of risk factors for the onset of tobacco use. The process of onset requires clarification. Regard- less of the age at which they smoke their first cigarette, young people appear to progress through a sequence of stages that takes them from receptivity to dependence on tobacco use (Leventhal and Clear-y 1980; Flay et al. 1983). Not all young people who try a cigarette become daily smokers; still, almost all of those who become daily smokers have experienced sin+ lar, well-defined stages in the behavior-acquisition process. The risk factors for each of these stages appear to differ; this -variation suggests that even within the seven years of adolescence (ages 11 through 17), devel- opmentally appropriate prevention programs should be used (Leventhal, Fleming, Glynn 1988). Developmental Stages of Smoking Flay (1993) discusses the five primary stages of smoking initiation among children and adolescents (Fig- ure 1). During the first or preparatory stage, attitudes and beliefs about the utility of smoking are formed. At this stage, even if no actual smoking behavior is enacted, the child or adolescent may see smoking as functional- as a way to appear mature, cope with stress, bond with a new peer group, or display independence (Perry, Murray, Klepp 1987). The second or trying stage encompasses the first two or three times an adolescent smokes. Peers are usually involved in situations that encourage trying (Conrad, Flay, Hill 1992). Whether the physiological effects of smoking are perceived to be negative and whether these tries are socially reinforced determine if an adolescent will proceed to the next stage (Leventhal, Fleming, Ershler, unpublished data), experimentation, which includes repeated but irregular smoking. At this third stage, smoking is generally a response to a particu- lar situation (such as a party> or to a particular person (such as a best friend). These influences will not yet have prompted a regular pattern of use. In the fourth stage, regular use, an adolescent smokes on a regular basis, usually at least weekly, and increasingly across a variety of situations and personal interactions. The final stage, nicotine dependence and addiction (see "Nicotine Ad- diction in Adolescence" in Chapter 21, is characterized by a physiological need for nicotine. This need includes tolerance for nicotine, withdrawal symptoms if the per- son tries to quit, and a high probability of relapse if the person does quit (Flay 1993). These stages have been further quantified and validated by Stem et al. (1987). The time interval from the initial try to the stage of regular use takes an average of two to three years, with considerable interval variation among individuals (Leventhal, Fleming, Glynn 1988). McNeill(1991) found in a prospective study that of those who experimented with cigarettes, approximately half were smoking on a daily basis within one year. Leventhal, Fleming, and Glynn (1988) suggest that the time interval from the initial try to the stage of regular use may be extended, particularly if the time is lengthened between the first 90 Psychosocial Risk Factors preventing Tobacco Use Among Young People and second try. This observation suggests that to delay both the onset of first trials as well as the progression to regular use, it seems critical to examine risk factors for first use. Since a young person may become a reguIar smoker in ody two to three years, the adolescent period of development (particularly middle school, junior high school, and senior high school) is a cruciaI time for pn+ vention efforts (Evans et al. 1978). Sociodemographic Factors in the Initiation of Smoking Sociodemographic factors involve the economic, political, social, and educational systems of a society. These factors can be determinants of behavior, such as tobacco use, even if the systems they originate in are not directly associated with the choice to begin that be- havior. Within these systems, social disorganization or Table 2. Characteristics of 27 prospective studies of smoking onset, various countries, 1980-1991 Study Year of publication Place Age* Time+ Numbefi (years) (months) (nonsmokers) Ahlgren et al. Alexander et al. Ary et al. Ary and Biglan Bauman et al. Brunswick and Messeri Charlton and Blair Chassin et al. Chassin et al. Collins et al. de Vries et al. Goddard Kellam, Ensminger, Simon Krohn et al. Lawrance and Rubinson M&au1 et al. McNeil1 et al. Mittelmark et al. Murray et al. Newcomb, McCarthy, BentIer Pulkkinen Semmer, Cleary, et al. Semmer, Lippert, et al. Skinner et al. Stacy et al. Sussman et al. Urberg, Cheng, Shyu 1982 1983 1989 1988 1984 1984 1989 1984 1986 1987 1990 1990 1980 1983 1986 1982 1988 * 1987 1983 1989 1982 1987 1987 1985 unpublished 1987 1991 Minnesota NSW Australia5 Oregon Oregon North Carolina New York City Manchester, UK Indiana Indiana Los Angeles Netherlands England Chicaga Iowa Illinois Minnesota Bristol, UK Minnesota Derbyshire, UK Los Angeles Finland Berlin-Bremen Berlin-Bremen Iowa Los Angeles Los Angeles Detroit suburb lo-11,11-12 10,11,12 12-13,14-15,X%16 12-15,15-16 14-15 12-16 12-13 11-16 11-16 12-13 Secondary 11-15 6-7 12-18 12-14 12-13 11-13 12-14,14-16 11-12 12-13,13-14,14-15 8-9 12-13 12-14 12-18 12-13 12-13 X&14,16-17 6 12 6 12 12 84 4 12 12 16 12 24 120 12 8 12 30 18 48 96 144 24 6 24 16 16 12 562 5,065 801 737 519 380 1,513 1,207 145 1,354 555 2,251 705 NAA 346 268 1,261 887 2,217 NA 135 761 763 426 1,116 338 NA Source: Adapted from Conrad, Flay, Hill 0992). *Age = Age (in years) of students at the beginning of the study. `Time = Number of months from the beginning of the study to the final follow-up wave. *Number = Number of nonsmoking students at the beginning of the study. SNSW Australia = New South Wales, Australia. ;INA = Not available. Psychosocial Risk Factors 91 Surgeon General's Report Figure 1. Stages of smoking initiation among children and adolescents Preparatory Stage Psychosocial risk factors include advertising and adult/sibling role models who smoke cigarettes. Psychosocial risk factors include peer influences to smoke, the perception that smoking is normative, and the availability of cigarettes. Psychosocial risk factors include social situations and peers that support smoking, low self-efficacy in ability to refuse offers to smoke, and the availability of cigarettes. Psychosocial risk factors include peers who smoke, the perception that smoking has personal utility, and few restrictions on smoking in school, home, and community settings. Adolescent forms attitudes and beliefs about the utility of smoking. w Never smokes Trying Stage Adolescent smokes first few cigarettes. L, No longer smokes Experimental Stage Adolescent smokes repeatedly but irregularly. fl No longer smokes Regular Use Adolescent smokes at least weekly across a variety of situations and personal interactions. t Quits smoking Addiction/Dependent Smoker Adolescent has developed the physiological need for nicotine. Sources: Adapted from Flay (1993); U.S. Department of Health and Human Services (19911. breakdown and discrepancies between role aspirations behavioral factors, such as normative expectations of and achievements may lead to incomplete or inappro- smoking, that affect the choice to use tobacco Flay 1993). priate social development of adolescents. Inappropriate Tobacco use may vary according to broad factors such as social development, in turn, can alter personal and an individual's socioeconomic status, family 92 Psychosocial Risk Factors Gtrume, age, gender, and ethnicity, especially when cta~ed across an entire population. Many of these ta,-tors are covered in Chapter 3 (see "Recent Patterns of Cigarette Smoking"). socioeconomic Status Low socioeconomic status (SE9 has been shown to predict smoking initiation in multiple longitudinal stud- ,es (Conrad, Flay, Hill 1992). Sernrner, Lippert, et al. (1987) examined tobacco use among students in two &ools in Germany. These investigators found that seventh- and eighth-grade students from the school in a low-income area (children of primarily blue-collar par- ents) had higher baseline rates of tobacco use than youth horn the school in a higher-income area. Low-income students were also more likely to begin smoking over the course of this six-month study. Low-income students had greater expectations of positive consequences of smoking, lower self-image scores, and more friends who smoked. One possible explanation of the impact of SES supported by these findings is that lower-income stu- dents may have to cope more often with stressful situa- tions, such as lacking sufficient resources or living in a one-parent family, and are therefore more likely to per- ceive smoking as a quick, easy coping strategy for stress or loneliness-and as a strategy that is socially accepted and effective (Semmer, Cleary, et al. 1987). Adolescents from low-income families may also have more role mod- els who smoke and less supervision to discourage ex- perimentation than adolescents from higher-income families (Perry, Kelder, Komro 1993). . Parental Education The level of parental education has been shown to have a significant impact on adolescent smoking lo+ havior in some studies. Although Ary et al. (1983) failed to find a relationship between parental education and children's smoking behavior, in a later report, Ary and Biglan (1988) found that low educational attain- ment among fathers was predictive of smoking onset in middle school youth. Waldron and Lye (1990) re- ported that high school seniors who had less-educated parents were more likely to have tried a cigarette and to have adopted cigarette smoking and were less likely to have quit smoking. Finally, Mittelmark et al. (1987) found that both adolescent femalesat all grade levels and adolescent males in grades 9 through 11 who began to smoke during the course of the study had parents with fewer years of formal education than their peers who remained nonsmokers. However, for seventh- and eighth- grade males in this study, parental educational level did not help to predict smoking initiation. See "Trends in Cigarette Smoking" in Chapter 3 for a trend analysis of adolescent smoking behavior and level of parental education. Number of Parents Living in the Home Several studies document an association between beginning to sinoke during childhood or adolescence and living in a single-parent home 05, Egan, Silva 1986; Elder, Molgaard, Gresham 1988; Isohanni, Moilanen, Rantakallio 1991; Goddard 1990; see `Sociodemographic Risk Factors for Smoking" in Chapter 3). These findings must be interpreted with caution, since most are from cross-sectional studies that were unable to determine with certainty which occurred first--living in a single parent home or smoking. If a predictive relationship does exist, a mechanism described by Castro et al. (1987) may help to explain the causal link. Their analyses found that living in a disrupted family system is an initial stressor that appears to predict social nonconfor- mity and affiliation with cigarettesmoking peers. In turn, as will be discussed later in this chapter, both social nonconformity and peer affiliation are significant pre- dictors of cigarette smoking among adolescents. Developmental Challenges of Adolescence The life stage of adolescence itself has been a con- sistent predictor of smoking initiation across studies (Alexander et al. 1983; Coombs, Fawzy, Gerber 1986; Bauman et al. 1990). The transition years from elemen- tary to secondary school seem to be a particularly high- risk time for adolescent initiation of tobacco use (Alexander et al. 1983; Coombs, Fawzy, Gerber 1986). Indeed, both the rate of onset of smoking and the preva- lence of regular smoking may level off during the high school years (Kandel and Logan 1984; McDermott et al. 1992). The relationship between adolescence and smok- ing initiation that is seen in these studies may be related to the developmental challenges of adolescence and to the social meaning of smoking. Adolescence is characterized by three major types of developmental challenges (Hooker 1991). The first involves physical maturation, particularly sexual matu- ration, and the establishment of intimate relationships. A second group of challenges involves responses to cul- tural pressures to begin making the transition to adult roles and responsibilities and to emotional independence from parents. The third area, the personal, involves establishing a coherent sense of self and a set of values to guide future behavior. As adolescence begins, efforts to meet these various challenges are characterized by ex- perimentation and risk-taking behaviors (Konopka 1991). Cigarette smoking is a risk behavior portrayed by Psychosocial Risk Factors 93 Surgeon General's Report advertising and role models as a way to be attractive to one's peers (see "Contemporary Strategies of the To- bacco Industry" in Chapter 3, and smoking appears to contribute to a positive social image in some settings (Sussman et al. 1987). The functions of smoking estab- lished by advertising and adult role models coincide with the challenges of adolescence and thus make this age group the most vulnerable for experimentation and initiation. Gender Although current smoking prevalence is roughly equal among males and females in the United States, different historical trends for men and women are evi- dent (Grunberg, Winders, Wewers 1991). Between 1974 and 1985, smoking initiation declined from 45 to 33 per- cent among young men but remained constant at 34 percent among young women (Fiore et al. 1989; see "Trends in Cigarette Smoking" in Chapter 3). Two stud- ies have discussed the impact of changing gender roles (e.g., more women are in traditionally male positions of authority) on smoking behavior and the resulting differ- ence in meaning that smoking has for males and females (Gritz 1984; Gilchrist, Schinke, Nurius 1989). Though some have suggested that generic factors that influence smoking initiation, such as appealing to the opposite gender, become more pronounced for one gender or the other at certain ages (Chassin et al. 1986), others have further concluded that the complex combinations of risk factors and processes leading to smoking are fundamen- tally different for females and males (Brunswick and Messeri 1984). In a review of research on gender differ- ences, Clayton (1991) found both considerable similari- ties (for instance, the influence of peer and parent models) and a number of possible differences between adoles- cent females and males who smoke. For example, ado- lescent girls who smoke are more socially skilled (e.g., more at ease with their peers, with strangers, or with adults) than their nonsmoking peers, whereas adoles- cent boys who smoke tend to lack such skills. Concern about body weight and the belief that smoking might help control body weight may also lead adolescent fe- males to begin smoking (Gritz and Crane 1991; Camp, Klesges, Relyea 1993). Further longitudinal research is needed to investigate gender differences in the determi- nants of tobacco use and thus to clarify the effect of gender on smoking initiation. from seventh to eighth grade, onset rates were higher for Hispanics and blacks than for whites and were lowest for Asians. Similarly, Maddahian, Newcomb, and Ben&r (1986) found that among California students followed from 7th through 12th grades, black youth maintained higher rates of smoking than youth of other ethnic groups. White and Hispanic students had intermediate rates of smoking, and Asian youth reported the lowest levels, although this difference decreased over time. Other national reports; however, indicate a higher percentage of smoking among white adolescents and young white adults than among their black or Hispanic counterparts (Remington et al. 198.5; Fiore et al. 1989; Bachman et at. 1991; see `Trends in Cigarette Smoking" in Chapter 3). These findings suggest different onset and quitting pat- terns among ethnic groups, as welt as potential regional differences in these patterns. Maddahian, Newcomb, and Bentler (1986) have proposed antecedents that may help explain these ethnic differences in tobacco use, including income levels that preclude or enable the acquisition of cigarettes, different levels of tobacco availability, and psychosocial influ- ences associated with belonging to a particular ethnic group. These investigators found that among California students, the level of income earned by youth had a significant impact on explaining ethnic differences in tobacco use. However, ethnic differences were virtually eliminated when availability and ease of cigarette acqui- sition from friends were considered. Sussman et al. (1987) found that unique combina- tions of psychosocial factors may be relevant to the eth- nic differences in smoking initiation. Three variables-availability of cigarettes, difficulty in refus- ing offers of cigarettes, and intentions to smoke in the futurewere significant predictors among youth from all ethnic groups included in their study. However, only among select groups were certain other variables impor- tant predictors of smoking initiation. For instance, social environmental variables (including peer smoking and adult smoking) were important predictors for white youth, but direct personal and social reinforcement vari- ables (including improved self-image and adult and peer approval of smoking) were more important variables for Hispanic youth. General risk-taking behavior was an important additional predictor for black youth only. The strongest additional predictors for Asian students in- cluded lack of general self-esteem and decreased school- related self-esteem. Ethnicity Research also indicates that the rate of smoking initiation varies among ethnic groups. Sussman et al. (1987) found that among California youth progressing Environmental Factors in the Initiation of Smoking Environmental factors are those that are exter- nal (or perceived as external) to adolescents and yet 94 Psychosocial Risk Factors Preuen ting Tobacco Use Among Young People may influence and affect their behavior. These fac- tors include the availability of cigarettes in the com- munity, the acceptability of smoking, peer and parental smoking, and adolescents' perceptions of the environment. Factors That Influence Tobacco Acceptability and Availability for example, communities choose to restrict exposure to tobacco-promoting images or restrict access to tobacco products (see Chapter 6 for further discussion of such restrictions). Currently, as more commumties and states adopt a variety of restrictive policies and programs, evaluation research is needed to examine the effective ness of these strategies for reducing onset of tobacco use. Factors that increase the acceptability and avail- ability of cigarette use at a societal or community level serve also to influence adolescent smoking behavior. Acceptability and availability are affected, in part, by the tobacco industry through advertising and other promo- tional activities; this topic is discussed thoroughly in Chapter 5. Acceptability of tobacco use may also be accomplished through persuasive, multiple, attractive role models who smoke on television programs or in movies (Bandura 1977). Acceptability is further rein- forced by community norms and policies that make to- bacco products relatively accessible for adolescents-for example, through sales to underage buyers and unre- stricted access to cigarette vending machines (see "Re- strictions on Minors' Access to Tobacco" in Chapter 6). The National Adolescent Student Health Survey (Ameri- can School Health Association et al. 1989) found that 79 percent of 8th graders and 92 percent of 10th graders considered it to be "very easy" or "fairly easy" to get cigarettes. Likewise, in the 1991 Monitoring the Future Project study (Johnston, O'Malley, Bachman 1992) 73 percent of 8th graders and 88 percent of 10th graders reported that it would be "fairly easyll or "very easy" to get cigarettes. In a study of adolescents in southern California, Sussman et al. (1987) found that both genders and all racial/ethnic groups except Asians tended to believe that they could obtain cigarettes with little diffi- culty. Findings from a national sample of teenaged (12- 17 years old) smokers confirm these perceptions and suggest that 1.5 million of an estimated 2.6 million un- derage smokers buy their own cigarettes (Centers for Disease Control [CDC] 1992). Of those who buy their own cigarettes, 84 percent purchase them from a small store, 50 percent from a large store, and 14 percent from a vending machine, either often or sometimes (CDC 1992). These reports have been substantiated by obser- vational studies of cigarette buying by young teenagers (see "Studies of Young People's Access to Tobacco" in Chapter 6). Several studies have found that the general availability of cigarettes predicts the onset of smoking (Bauman et al. 1984; Semmer, Cleary, et al. 1987). Factors that increase acceptability and availability support a social milieu in which cigarette smoking may appear socially functional. On the other hand, a social milieu can decrease the risk of adolescent smoking-if, Interpersonal Factors Interpersonal factors in the initiation of smoking involve opportunities for adolescents to perceive, through modeling by adults and peers who smoke, apparent advantages of smoking. These role models (particularly peers) also provide the situations (e.g., parties, staying overnight) in which cigarettes are first tried by adoles- cents (Lawrance and Rubinson 1986). Interpersonal fac- tors have also been labeled "social learning variables" (Bandura 1977; Flay 1993) because the social functions or meanings of smoking are learned in the context of social interactions. The research on interpersonal factors has carefully explored the roles of parents, siblings, friends, and peers in the process of initiation. Parental Smoking The research on the influence of parents' smoking behavior on their children's cigarette use has included multiple studies of the relative risk of initiation if one or both parents smoke. Bauman et al. (1990) found a consis- tent relationship between parental and adolescent smok- ing in a cross-sectional study of 12- through 14year-olds in 10 urban areas in the southeastern United States. Com- pared with adolescents whose parents had never smoked, those whose parents currently smoked were almost twice as likely to smoke; those whose parents had once smoked were three times as likely to smoke. A similar influence of parental smoking was noted by Chassin et al. (1986) for females in a longitudinal study of 12- through 18 year-olds from the midwestem United States. In Sussman et al. (1987), a longitudinal study of ll- through 14year- olds in southern California, parental smoking was pre- dictive of a child's smoking for whites but not for Hispanics, blacks, or Asians. This finding matches that of Hunter et al. (1987) in a longitudinal study of 8- through 17-year-olds in the southern United States, in which pa- rental behavior was predictive of children's smoking initiation for whites but not for blacks. By contrast, parental smoking behavior was a poor predictor of smoking initiation in several other studies, including the longitudinal study McCaul et al. (1982) conducted among II- through 14year-old whites living in the north-central United States. No relationship was found in the Botvin et al. (1992) cross-sectional study of Psychosocial Risk Factors 95 161-235 95-4 Surgeon General's Rf2port 608 inner&-y blacks aged 11 through 13 or in the longi- tudinal study of 2,209 primarily white ll- through 17- year-olds in Minnesota Wittelmark et al. 1987). In Quine and Stephenson's (1990) cross-sectional study of over 2,000 Australians aged 10 through 12, parental smoking was not associated with children's smoking but was related to children's intentions to smoke when older. Conrad, Flay, and Hill (1992) summa rizai the find- ings of 27 prospective studies on the onset of smoking that have been publish4 since 1980 (see Table 3). In 15 of the studies, parental smoking factors were investigated. The researchers concluded that parental smoking was predictive in seven studies, predictive only for females in two studies, and not predictive in six others. Chassin et al. (1984) suggested that parental smoking may influence the preparatory or initial trying stages, as well as the stability of smoking patterns from adolescence to adulthood (Chassin et al. 19911, but pa- rental smoking appeared to be less influential during the transition to regular smoking. Sibling Smoking Over the past two decades, extensive reseamh on the influence of sibling smoking indicates a primarily positive relationship between an older sibling's smoking and a younger (adolescent) sibling's begin&g to smoke. In a IO-year longitudinal study of 6,311 ado- lescents Gnitially 11 through 13 years old), sibling smok- ing was found to be one of four factors that was predictive of increased risk of initiating regular smoking and predictive of smoking prevalence after 10 years (Swan, Creeser, Murray 1990). In the McNeill et al. (19881 longitudinal research with 2,159 British 1 l- through 13year-olds, having a sibling who smoked appeared to increase the odds of smoking initiation by a factor of 1.69. Botvin et al. 0992) reported that sibling smoking was one of five variables that accounted for 29 percent of the variance in smoking in their cross- sectional study of 522 inner-city blacks aged 11 through 13. O'Connell et al. (1981) found sibling smoking to be among the first three factors associated with weekly Table 3. Predictors of smoking onset in 27 prospective studies Prediction of smoking onset Number of supportive findings Number of unsupportive findings Percent support Socioeconomic status Environmental factors Family smoking Family approval Other adult influences Peer use and approval Normative estimates Offers/availability Family bonding Peer bonding School influences Religious influences Behavioral factors skills Other behaviors Personal factors Knowledge/beliefs Attitudes Personality factors Intentions to smoke 16 5 76 18 8 69 6 8 43 5 3 63 27 5 84 4 1 80 7 1 88 9 6 60 11 4 73 20 5 80 0 1 0 3 12 16 8 23 8 100 86 64 73 77 89 Source: Adapted from Conrad, Flay, and Hill (1992). 96 Psychosocial Risk Factors prezvnting Tobacco Use Among Young People smoking among 6,224 students aged 10 through 12 in New South Wales, Australia. Mittelmark et al. (1987) found that experimenting with cigarettes was associated rvith sibling smoking only for females and ll- through 13-year-old students. This finding was similar to the Chassin et al. (1984) research that found sibling smoking more influential in the early stages of cigarette use than in the later stages. Gender and race differences in the effect of sibling smoking have also beeri noted. Hunter et al. (1987) found sibling smoking predictive for white males, a sister's smoking predictive for white females, and a brothex's smoking predictive for black males and fe- males. Brunswick and Messeri (1983) found sibling smok- ing influential only for males. In the Muscatine Study (Krohn, Naughton, Lauer 1983, the maintenance (not initiation) of smoking was associated with a brother's smoking. Finally, in Conrad, Flay, and Hill's (1992) re- view of 27 prospective studies, four of the five studies that examined this factor indicated that sibling smoking was associated with onset. Peer Smoking and Peer Behaviors One of the areas of widest investigation in the antecedents of cigarette smoking concerns peer smoking and related peer behaviors. Peers may be defined as persons of about the same age who feel a social iden- tification with one another. The influence of peers has been posited as the single most important factor in deter- mining when and how cigarettes are first tried. Flay et al. (1983) suggest that smoking may primarily represent an effort to achieve social acceptance from peeis and that it may particularly be an experimental "adult" activity that is shared with the peer group. Leventhal and Keeshan (1993) suggest that adolescents are not only influenced by, but also influence and construct, their peer groups. These researchers propose that small groups of adolescents "construct shared so&l environments in which they perceive themselves and other(s) as having mutual cognitive, emotional, and valuative reactions.. . , the intersubjectivity created by sharing generates a sense of wellness. This se- of mutuality enhances the attrac- tiveness of the group and may lead to incorporation of the self-image of the others into the image of one's own self" (p. 269). Multiple cross-sectional and longitudinal studies worldwide substantiate the relationship between smoking onset and pee=' (or friends') smoking (Shean 1991; DConneIl et al. 1981; Ogawa et al. 1988). In their research, Bauman et al. (1990) found that smoking most often occurred in the presence of best friends. Sixty percent of 1 l- through 17-year-olds reported that they had first smoked, and 72 percent reported that they had most recently smoked, with close friends (Hahn et al. 1990). Among 12- through 14-year-olds, those whose best friend smoked were four times more likely to be smokers than those whose best friend did not smoke. Best friend's smoking predicted both smoking experi- mentation and prevalence among urban San Diego ado- lescents from a variety of ethnic groups (Elder, Molgaard, Gresham 1988) and among white and black 8- through 17-year-olds in Louisiana (Hunter, Vizelberg, Berenson 1991). Best friend's cigarette use was predictive of the first try at smoking, whereas having a majority of friends who smoke was predictive of the second cigarette (Leventhal, Fleming, Glynn 1988). In the Conrad, Flay, and H+ (1992) review of the recent prospective research, friends' smoking was pre- dictive of some phase of smoking in all but one (Newcomb, McCarthy, Bentler 1989) of 16 studies. A positive association of peer smoking with onset of smok- ing in 88 percent of these more rigorous, longitudinal studies suggests a clear link between peers' smoking and cigarette use. This link may be mediated by personal factors, such as self-efficacy (or self-confidence), and ap pears to be most potent in the earlier stages of smoking (Pomerleau 1979; Pederson and Lefcoe 1986; Chassin, Presson, Sherman 1990). Social Bonding The interpersonal environment has also been char- acterized by the degree of, social bonding, or attach- ment, between the adolescent and important others or illStitUtiOIlS. The findings on family bonding variables in smok- ing onset, particularly attachment to mothers or fathers, have been inconsistent; those related to peer bonding, including the number of friends, level of social life, participation in antisocial activities, and having a boy- friend or girlfriend, were all found to be predictive of onset (Conrad, Flay, HiU 1992). Bonding with peers who smoke appears to increase the risk of smoking, perhaps because such bonding takes precedence over attachments to the family. Perceived Environmental Factors The perceived environment includes the smoking- related norms, social support, expectations, reactions, and barriers that adolescents sense in their environment. The perceived environment may be a more proximal influence on smoking initiation than the actual environ- ment (Lessor and Jessor 1977). For example, 12-year-olds who believe that `lots of people" their age smoke may Psychosocial Risk Factors 97 Surgeon General `S Report be more inclined to begin smoking to fit in than if they were aware that only 5 to 7 percent of their peers ac- tually smoke. Norms Norms may be defined as what an individual in a particular group perceives she or he ought to do and what is perceived as acceptable behavior for a given age group, gender, or other subgroup. Gerber and Newman's (1989) research on smoking-related norms details ado- lescents' perceptions of the percentage of all adults, peers, and classmates they think are smokers. These investiga- tors found that experimental adolescent smokers who increased their smoking levels over the course of the one-year study period perceived more smoking among their classmates than did those who had decreased their smoking in the same time period. Similarly, Leventhal, Fleming, and Glynn (1988) report that youth who par&i- pated in their studies greatly overestimated the propor- tion of peers and adults who smoke. The adolescents believed that 66 percent of their peers and 90 percent of adults were smokers, thus overestimating smoking preva- lence by at least a factor of three. Collins et al. (1987) examined the predictive influ- ence of norms in a longitudinal study of 3,295 students aged 11 and 12 in 56 junior high schools in Los Angeles. Like Chassin et al. (Chassin et al. 1984; Chassin, Presson., Sherman 1990), they found that adolescents who made relatively high estimates of regular smoking prevalence were more likely to try smoking, to become smokers, or to increase the amount they smoked over 1 and 1.5 years of the study. Sussman et al. (1993) discussed further aspects of normative influence and implications for the content of prevention programs. Previous smoking and peer smoking were the main predictors of overestimates in the Collins et al. (1987) study. In Shean's (1991) re search in Australia, beliefs about the number of adoles- cents and adults who smoke predicted smoking in young adulthood eight years later. In part, these normative expectations may be a function of these beginning smok- ers' actual exposure to a disproportionate number of smokers, including adults and peers. Social Support for Smoking Social support includes perceived approval or dis- approval of adolescent cigarette smoking by parents, siblings, peers, and important others, such as teachers or employers. One way that social support is manifested is through peer-group pressure, either through support or discouragement of smoking. Peer pressure is not always negative; it has been used successfully in many prevention programs (Klepp, Halper, Perry 1986). Still, in the study by Hahn et al. (19901, the urging of one or more acquaintances--most likely peers or close friends-prompted over half the instances of adolescents' trying a cigarette for the first time. In the Chassin et al. (1986) study, females who saw their friends as more supportive than critical about their smoking were more likely than those who saw their friends as less supportive to become regular smokers one year later. Similarly, many adolescent smokers in another study reported, `My friends like me because I smoke" (Hunter et al. 1987). In the same study, smokers were less likely than nonsmokers to report, "My parents don't want me to smoke." Peer approval of smoking was an important predictor for smoking onset among whites and Hispanics, whereas adult approval was an important predictor for Hispanics and Asians among 874 southern California ll- through 13-year-olds (Sussman et al. 1987). Social support also includes the general support or approval the adolescent receives from others. This kind of support appears to play a role in predicting onset (see `Trends in Knowledge and Attitudes About Smoking' in Chapter 3). Chassin et al. (1986) found that those adolescents who reported that their parents were gener- ally supportive of them were less likely to begin smoking or to become regular smokers than were those who perceived that their parents were not generally support- ive of them. However, those who reported that their friends were supportive of them were more likely to become smokers than were those who did not report such support. Similarly, males who reported that they lived in families in which they had limited involvement in family decisions were more likely to become smokers than males from families where high involvement in family decisions was reported (Mittelmark et al. 1987). Adolescents who reported regularly caring for them- selves after school were at increased risk of smoking (Richardson et al. 1989). Finally, adolescents who be- lieved that parents, siblings, friends, and teachers would not care if they smoked were at higher risk of initiating smoking after 2.5 years than were those who believed that others would care if they smoked (McNeill et al. 1988). Lack of concern by parents appears to increase risk, particularly for males (Swan, Creeser, Murray 1990). General parental support of the adolescent and concern about the adolescent's smoking appears to decrease risk. Parental Reaction to Smoking Parental reaction to use and perceived parental strictness have also been associated with onset. Hansen et al. (1987) examined the influence of perceived parental reactions to cigarette smoking (as well as alcohol and marijuana use) among 293 Los Ange les lO- through 12-year-olds. Parental anger toward the 98 Psychosocial Risk Factors pmwrzting Tobacco Use Among Young People adolescent's smoking or approval of the adolescent's &using to smoke, together with two other drug-related Variables, indirectly predicted low levels of use. Chassin rt al. (1986) evaluated perceptions of parental strictness; their findings support the need for interventions tailored to different age groups of adolescents. Among the young- et subjects (10 through 12 years old), those who per- ceived that their parents were more strict than other parents were actually more likely to begin smoking over a one-year interval. Among the oldest subjects (14 through 16 years old), however, those who perceived that they had stricter parents were less likely to begin to smoke. Those aged 12 through 14 years were not af- fected by parental strictness. Other researchers have further noted that extremes of parental strictness, from inadequate restraint to overcontrol, are associated with problem behaviors (Pandina and Schuele 1983). Adult Discrepancy Shean (1991) developed the concept of adult dis- crepancy-the discrepancy between the "adult" behav- iors in which an adolescent wants to participate at age 14 (such as going to a nightclub) and what was actually done by his or her parents when they were age 14. Those adolescents with high discrepancy were more likely to be smokers as young adults than those with low discrep- ancy, which may suggest that adolescents with high discrepancy tend to make the transition to an adulthood not modeled by parents. The adult discrepancy factor, in addition to peer, sibling, and parental smoking, inten- tions to smoke, and effects of cigarette advertisements, predicted young adult smoking over an eight-year interval. This study points to the strong effect of the social environment on the onset and maintenance of adolescent smoking. Behavioral Factors in the Initiation of Smoking Behavioral factors involve patterns of behaviors that are directly related to cigarette use, such as aca- demic achievement, health-compromising and health- enhancing behaviors, and smoking-related skills. These associated behavior patterns may increase the risk of smoking by providing opportunities to view smoking as functional or appropriate. Academic Achievement The onset of smoking has been shown repeatedly to be related to poor academic achievement (see Table 6 in Chapter 3). Relevant indicators of students' achieve- ment include scholastic performance (grades), high school graduation, truancy rates, and future professional or educational aspirations. Borland and Rudolph (1975) examined the relative predictability of scholastic per- formance, parental smoking, and socioeconomic status among 1,814 high school students in Pennsylvania. The strongest correlate to smoking was scholastic performance; those with the highest grades were found to smoke less than those with the lowest grades. This finding is consistent with Brunswickand Messeri's (1984) research among young, urban black adolescents in Harlem, New York, as well as the Sussman et al. (1987) research with Hispanic and Asian adolescents in south- em California. Students who disliked school and feared school failure were more likely to begin smoking in early adolescence than those who liked school and had expec- tations of school success (Ahlgren et al. 1982). In two well-designed studies, adolescents who had limited ex- pectations of academic achievement increased their smok- ing levels over time (Gerber and Newman 1989; Chassin, Presson, Sherman 1990). Still, among inner-city black seventh-grade students, Botvin et al. (1992) found that academic achievement was not a significant predictor of current smoking or intentions to smoke. Conrad, Flay, and Hill (1992) found that 80 percent of the prospective studies on the onset of smoking indi- cated a positive relationship between low academic achievement (and other school-related factors) and smok- ing onset. In a longitudinal study of 739 junior high students (66 percent white, 15 percent black, 10 percent Hispanic) in Los Angeles, the research team of Newcomb, McCarthy, and Bentler (1989) concluded that an adolescent's "academic lifestyle orientation" (measured by grades, educational aspirations, personal and profes- sion plans, and expectations) was the central organizing influence on teenage smoking behavior, teenage emo- tional well-being, social relationships with smokers, and adult smoking behavior. This centrality emerged even when emotional well-being, self-efficacy, personal ambi- tion, and friends' smoking behavior were considered. Other Adolescent Behaviors The association between smoking and other ado- lescent behaviors has been examined as an extension of Jessor and Jessox's (1977) concept of the covariation of problem behaviors, including both unconventional be- haviors (such as alcohol and drug use) and conventional behaviors (such as academic achievement and church attendance). Cigarette use among adolescents has been studied as "problem" behavior; that is, studies have ex- amined its association with alcohol and drug use, risk- taking behaviors, proneness to deviance, early antisocial behavior, and group membership, as well as its associa- tion with constructive or health-enhancing behaviors. Some adolescents see problem behaviors as a way to PsychosociaI Risk Factors 99 Surgeon General's Report achieve--and signal to others-the precocious transition to independence and autonomy. The association .of cigarette smoking and illegal drug use suggests that cigarettes may be an entry-level or gateway drug in a sequence of progressive drug use (see "Smoking as a Risk Factor for Other Drug Use" in Chapter 2 and "Smoking and Other Drug Use" in Chap ter 3). The suggestion here is not that smoking causes illegal drug use, but that those who use illegal drugs have most likely smoked cigarettes previously. In the following studies, smoking is considered a gateway drug, since the decision to smoke appears to facilitate the deci- sion to use other drugs. Scheier and Newcomb (1991) studied 717 junior high school students in northern California. They con- cluded that early cigarette use predicted illegal drug use during the two-year study period. This finding comple- ments the work of Fleming et al. (1989) and Newcomb and Bentler (19861, who emphasized the crucial role of cigarette smoking in the progression to marijuana and hard drug use, even without the mediating impact of alcohol use. Those authors concluded that these sub- stances are reciprocally influential over time, with in- creased use of cigarettes associated with increased use of illegal drugs. By young adulthood, a clear correlation seems to exist between cigarette smoking and illegal drug use. For example, in Brunswick and Messeri's (1983) 6- to &year prospective study of 536 blacks aged 11 through 13 in Harlem, New York, at follow- up (aged 18 through 23), 56 percent of males and 59 percent of females who had used illegal drugs smoked cigarettes, whereas 24 percent of males and .35 percent of females who had not used illegal drugs smoked cigarettes. Risk Taking, Rebelliousness, and Deviant Behaviors Risk taking, rebelliousness, and deviant behaviors are generally those behaviors that are considered uncon- ventional, antisocial, or alienated from traditional insti- tutions. The research literature has repeatedly characterized adolescent drug use as one manifestation of rebelliousness and deviance fJessor and Jessor 1977; Chassin, Presson, Sherman 1989). By testing Jessor and lessor's (1977) model, Chassin et al. (1984) found that proneness to deviance significantly predicted smoking onset in a longitudinal study of secondary students, al- though not for. those who had already experimented with cigarettes. In a subsequent study of high school students, Chassin, Presson, and Sherman (1989) found that in some instances, deviance was associated with independence and personal control; whether psycho- logically constructive or not, however, deviance was a significant predictor of cigarette smoking. A risk-taking orientation (that is, an inclination toward excitement and chance taking) was similarly associated with trying a cigarette for the first or second time (Leventhal, Fleming Glynn 1988). Risk taking was also a significant predictor of smoking initiation in the Colhns et al. (1987) study of 1 l- and 1Zyearolds in Los Angeles. In the Sussman et al. (1987) study of southern California adolescents, risk taking predicted smoking among blacks, but the associa- tion was not significant for whites, Hispanics, or Asians. Conrad, Flay, and Hill's (1992) review of prospective research on smoking initiation cited five studies that associated rebelliousness, risk taking and proneness to deviance with smoking onset (see "Cigarette Smoking and Other Health-Related behaviors" in Chapter 3). Peer Groups During the past two decades, the relative irnpor- tance of adolescent bonding with peers has increased, while the importance of bonding with parents has de- clined (Perry, Kelder, Komro 1993). This shift has al- lowed more time, opportunity, and social support for dysfunctional behaviors, such as cigarette use. Adoles- cent females who spent most of their free time with their families, for example, were less likely to begin smoking than those who spent little free time with their families (Brunswick and Messeri 1984). As Flay (19931 notes, "youth alienated from conventional culture have more opportunities than others to observe substance use and its positive functions. . . . They are also more likely to overestimate the proportion of their peers who use these substances--because they are likely to be associating with groups who actually do use . . . . [and] deviant cul- tures reinforce these youth when they do use, for ex- ample, by acceptance into groups" (p. 369). Leventhal et al. (1991) observe that parents, teach- ers, and other adults seldom discuss with youth the intense biological and social changes that occur in ado- lescence: `When such a dialogue is absent. . . the peer group becomes the predominant influence integrating and shaping the adolescents' vague yet pressing internal states" (p. 586). Participation in Athletics and Other Health-Enhancing Behaviors Health-enhancing behaviors, such as sports involve- ment, might moderate a high-risk environment (Rantakallio 1983). Swan, Creeser, and Murray (19901 found that girls were significantly less likely to begin smoking if they were involved in an organized sport, but were significantly more likely to begin smoking if they participated in organized social activities. Involvement in sports did not appear to affect boys' rate of smoking 100 Psychosocial Risk Factors p,n,&kg Tobacco Use Among Young People onset in this study. McCaul et al. (1982) found no asso- ciation between boys' smoking and participation in ex- tracurricular activities. Among urban black femrales in ~~wic?k and Messeri's (1984) study, those who re p~ecl minimal concern about their health & those who reported a larger appetite were more likely ho begin sm&j.ng; in contrast, black males who had the greatest number of health-related activities and were of normal body weight were more likely to begin smoking than other black males (Brunswick and Messerr 1983). Sussman et al. (1993) found that among you& at the h$vst risk of smoking, those who did not smoke re- p&d that they valued their health. Finally, in Kelder's (19%) longitudmal study of secondary school ,-dents ~JI the north-centi United States, cigarette smoking was found to be related to poor food choices and less exercise after the eighth grade; the correlation betwm these behaviors was stronger with increasing age. Behaviord Skih The final set of behavioral factors comprises the tj&avion3l skills that are necessary to begin smoking tfme that are necessary to resist influences to smoke, and those that are necessary to cope with other social situations that might indirectly encourage cigarette use. Hahn et al. (1990) found that 42 percent of smoking expairnent~ had asked for their first cigarette- In the Sussman et al. (1987) study in southern California, diffi- culty in refusing offers to smoke predicted onset for all four ethnic groups, particularly for whites and blacks, for whom it was the strongest predictive factor found in the study. This difficulty in refusing an offered cigarette appears to be strongly influenced by the offering friend's attitudes and behaviors (e.g., being persistent or critical if refused), particularly for high-risk adolescents (Saiomon et al. 1984; Lawrance and Rubinson 1986; Reardon, Sussrnan, Flay 1989). Conrad, Flay, and Hill (1992) re- viewed three prospective studies and found that refusal or resistance skills against smoking were associated with lower rates of onset. Generally, cigarette use can be viewed as a coping mechanism-a skilled response designed to close the gap between an adolescent's current position and goals (Leventhal et al. 1991). Smoking serves as a coping response if it brings the adolescent closer to a valued goal, such as acceptance in a peer group. Smoking may also serve as a coping response to stress or &tress Wrlls and Shiffman 1985; Castro et al. 1987). These studies suggest that youth need more general social skills, such as being able to cope with various kinds of stress or social pmssures, to help them manage the many devel- opmental demands of adolescence (Franzkowiak 1987). A more comprehensive concept of skills that has been used in prevention efforts is discussed in Chapter 6 (see "lnstiUing Skills for Resisting Social Influences to Smoke" and "ExemplaryPmgrams for ResistingSocialInfluences"). Personal Factors in the Initiation of Smoking Personal factors are those that are inherent in the individual, they include cognitive processes, values, per- sonality constructs, and psychological well-being. These factors can be considered the personal filters through which so&demographic and environmental factors pass as they influence behavior. Personal risk factors also explain differences in behavior among individuals ex- posed to the same or simiIar environments. The per- sonal factors that have been examined in the research literature include levels of knowledge about the health consequences of smoking, the functions or meanings of cigarette use among adolescents, the subjective expected utility C3ELJl of smoking self-esteem, self-image, self- efficacy in refusing offers of cigarettes, personality vari- ables, and emotional well-being. Knowledge of Long-Term Health Consequences Knowledge of the long-term health consequences of smoking has not been a strong predictor of adolescent onset (Collins et al. 1987; Krohn, Naughton, tiuer 1987; Sussman et al. 1987; Conrad, Play, Hill 1992; Royal Col- lege of Physicians of London 1992), perhaps because virtually all U.S. adolescents--smokers and nonsmokers alike-are aware of the long-term health effects of smok- ing and because many adolescents feel inherently invul- nerable in their characteristically short-term view (Gerber and Newman 1989). Belief that smoking has short-term effects on health appears to be a more powerful influence than knowledge of long-term health effects (Krohn, Naughton, Lauer 1987; McNeill et al. 1988). Similarly, belief in personally relevant nega live social consequences of smoking has been associated with a dechne in smok- ing prevalence among secondary school students (Chassin et al. 1987). Botvin et al. (1992) found that lack of concern about the harmful effeds of smoking was associated with intentions to smoke among young, inner-city black adolescents. Similarly, dismissing or rnhimizing the health consequences of smoking has been associated with both initiation of cigarette use and adult smoking levels Wittelmark et al. 1987; Swan, Creeser, Murray 1990). Krohn, Naughton, and Lauer (1987) found that smoking behavior predict& beliefs about the health effects of smoking more than beliefs predicted future cigarette use. Knowledge of the health consequences of smoking may or may not deter some adolescents from begiming to smoke; beginning to smoke appears to ac- centuate adolescents' denial of the health consequences. Psychosocial Risk Factors 101 Surgeon General's Report Functional Meanings of Adolescent Smoking The question of why adolescents begin to smoke has led to multiple examinations of the meanings of cigarette use, the utility of smoking, and the functions that smoking serves in an adolescent's life (Leventhal and Clear-y 1980; Perry, Murray, Klepp 1987). Examin- ing smoking from the perspective of the adolescent is a departure from viewing the onset of smoking exclu- sively as a response to the social environment or as capricious, arbitrary behavior. Since knowledge of the harmful consequences of cigarettes does not appear to deter onset, researchers are examining the social reasons and purposes of smoking. Adolescents who begin to smoke perceive a more functional purpose of smoking than those who are nonsmokers (Gerber and Newman 1989). Adolescent smokers are more likely to view smoking as a way to act mature, be accepted by a peer group, have fun, cope with personal problems and boredom, or be rebellious (Perry, Murray, Klepp 1987). Cigarette smoking has also been shown to be a coping behavior for adolescents who are dealing with disruptive and stressful family events (Castro et al. 1987). Hunter et al. (1987) found that adolescent smokers were significantly more likely than nonsmokers to believe that smoking has psychological and physiological benefits. They were also less likely to believe that others smoked for negative reasons, such as to "show off." In the research of Hahn et al. (1990), regular smok- ers were asked why they first had tried cigarettes arrd why they had most recently smoked. Sixty percent re ported that curiosity was the reason for their first try, 13 percent said that they wanted to fit in with a group, and 10 percent reported that they were pressured into it. For most recent use, 27 percent reported that they smoked for pleasure, 20 percent out of dependence, 17 percent because they were curious, and 10 percent to fit in with the group. These findings are consistent with Chassin et al. (19841, who suggest that positive attitudes toward smoking, such as the idea that smoking is fun or pleasur- abIe, are a better predictor of the transition to regular smoking than they are for first experimentation. In gen- eral, these investigators found that positive attitudes to- ward smoking may increase as a function of age. Botvin, Botvin, and Baker (1983) found that independent of the smoking status of friends, students in the eighth grade (13- and 14-year-olds) were more likely to have a posi- tive social image of smoking than students in the seventh grade (ll- and 12-year-olds). Subjective Expected Utility Carolina. SEU is defined as the extent to which an individual expects the overall consequences of a behav- ior, such as smoking, to be positive or negative. Fishbein (1980) found that behavioral intentions to smoke were related to whether more positive or negative conse quences were expected from smoking. SEU was found to be predictive of the onset of smoking over a one-year interval and of increased smoking levels among baseline smokers (Bauman et al. 1984). In a second study, SEU was found to be mediated by the adolescent's perception of personal control; current smokers with the highest scores for internal locus of control (that is, the belief that they have control over what occurs to them) were more likely to have been influenced by SEU Wunan and Fisher 1985). Therefore, regular smoking appears more likely to be motivated by internal processes than are initiation and trying, which may primarily be products of exposure to a high-risk social environment. Self-Esteem The process of individuation and identity forma- tion is inherent to adolescence. The adolescent's sense of self evolves as she or he interacts with parents, school, and peers and considers options for the future. Self- esteem, or an individual's qualitative self-evaluation, emerges from these contexts (Young and Werch 1990). In several studies, the onset of smoking has been associ- ated with lower self-esteem. Young and Wench (1990) found that young nonsmokers and those with no inten- tion of smoking in the future had higher self-esteem relative to family, school, and peers than frequent users or those who intended to use in the future. Ahlgren et al. (1982) found that low self-esteem within family or school contexts was associated with initiation and continuance of smoking. Self-esteem concerning school predicted intentions to smoke among young, inner-city black ado- lescents (Botvin et al. 1992) but did not predict actual smoking. Stacy et al. (1992) found that general low self- esteem directly predicted smoking onset in a multiracial, southern California sample yet did not significantly mediate friends' social influences. In their review of prospective research, Conrad, Flay, and Hill (1992) conclude, "Self-esteem received fairly consistent support [as a predictor of initiation] from the reviewed longitudi- nal studies. This is better than we would have ex- pected from our reading of previous cross-sectional studies" (p. 20). Self-Image Some adolescents may smoke cigarettes to enhance their low self-esteem by improving their external im- Bauman et al. (1984) have examined the SEU of smoking for adolescents in a longitudinal study in North d I age-that is, by appearing mature & "cool." Smoking onset was seen as a way to improve self-image among 102 Psychosocial Risk Factors preventing Tobacco Use Among Young People whites, blacks, and Hispanics in southern California (Sussman et al. 1987). Role models who smoke am frequently seen to have socially desirable attributes- they seem tough, sociable, and sexually attractive (Chassin, Presson, Sherman 1990). Adolescents who believe that smoking bestows these attributes may see smoking as a powerful mechanism for self-enhancement. These young people may experiment with smoking to try to adopt a perceived positive social image and thereby improve the way others, particularly peers, view them (Chassin, Presson, Sherman 1990; Leventhal et al. 1991). If peers respond favorably to this strategy, these new young smokers may continue to smoke, since the behav- ior has proved functional for them in creating an accept- able self-image. Self-Efficacy An individual's efficacy (or confidence) in perform- ing specified skills and behaviors is a significant media- tor of peer influences to smoke (Bandura 1986). Ellickson and Hays (1990-91) found that low self-efficacy, as mea- sured on a scale of having little or much confidence in resisting offers of drugs, was associated with drug use, including smoking. DeVries, Kok, and Dijkstra (1990) found that self-efficacy in resisting offers to smoke was the best predictor of smoking among adolescents in the Netherlands over a oneyear interval. Similarly, Lawrance and Rubinson (1986) found that young adolescents' per- ceptions of their ability to resist cigarette smoking corre- sponded to their self-reported smoking. Finally, Stacy et al. (1992) found in their cross-sectional study of high school students not only that low self-efficacy in resisting social influence was a significant predictor of smoking but also that high self-efficacy was the only significant mediator of friends' social influences on smoking. There fore, self-efficacy, a personal factor, appears to act as a buffer that protects adolescents from potent peer influ- ences to smoke (Conrad, Flay, Hill 1992). Personality Factors The research on personal factors has also examined many personality factors for their association with onset, in part to assess whether underlying emotional or psycho- logical problems predict adolescent smoking. Personality characteristics that are related to deficiencies in self- control, such as impulsiveness and sensation-seeking tendencies, are important and were discussed earlier in this chapter in connection with behavioral factors. Psychological Well-Being Several studies have associated cigarette smoking and symptoms of depression among adolescents. Covey and Tam (1990) showed an independent relation of depressive mood, friends' smoking behavior, and living in a single-parent home with cigarette smoking among 205 urban 11th~grade males and females. Depression scores correlated with the number of cigarettes smoked. Malkin and Allen (1980) found a significant association between smoking and depression among males in a study of 229 rural Bth- and 11 th-grade students, a fmding that was replicated for both genders by Kaplan et al. (1984). Stein, Newcomb, and Bentler (unpublished data) found that cigarette use was positively associated with being extroverted and negatively associated with having symptoms of depression among junior high school stu- dents in Los Angeles. Cigarette use, however, signifi- cantly predicted symptoms of depression in these young people four and eight years later (Newcomb, McCarthy, Bentler 1989). These findings may reflect the addictive quality of tobacco use beyond the earliest experimental states and the relationship between smoking and de- pression, since depression is a personality factor that usually persists over time. Smoking might be a short- term, self-medicating response to symptoms associated with depression. In the long-term, however, this effect would diminis h; as tolerance to nicotine increases, the possible antidepressant effects of smoking (such as alert- ness, euphoria, and calm) dissipate (Newcomb, M&Whey, Bentler 1989). Similarly, Leventhal, Fleming, and Glynn (1988) found that reported feelings of help lessness were associated with more rapid movement to a second and third experiment with smoking; however, these feelings were not related to the initial experimenta- tion. The association of smoking and suicide attempts, another clearly serious symptom of depression, is pre- sented in Chapter 3 (see "Cigarette Smoking and Other Health-Related Behaviors"). Flay (1993) suggests that symptoms of depression may be a response to distress associated with stress and poor family bonding. He points out that stress and distress have been associated with drug use, including tobacco use (Wills and Shiffman 1985). The research of Kellam, Ensminger, and Simon (1980) suggests that this cycle may begin early in life. In their study of first-graders (aged five through seven) in Chicago, they found that males rated by observers as aggressive or as alternately shy and aggressive had the highest rate of drug use, including cigarette use, 10 years later; no long-term psy- chological predictors were found for females. In another study (Brunswick and Messeri 19841, adolescent males were more likely to begin smoking if they were peSSMS- bc about the likelihood of the world becoming any better or if they held low expectations for their own future; for adolescent females, a shortened time perspective (i.e., a Psychosocial Risk Factors 103 Surgeon General's Rep-t limited ability to conceptualize their future) was the most important psychogenic predictor of initiation. Adolescent Smoking Behavior as a Risk Factor for Subsequent Smoking Intentions to Smoke Since intentions are viewed as proximal to perfor- mance, the research on smoking behavior as a predictive factor of smoking includes behavioral intentions to smoke. In several studies, intentions to smoke have been associ- ated with both the onset and continuation of smoking. Sussman et al. (1987) found in their longitudinal study in southern California that the intention to start smoking was one of 0nIy three factors that predicted onset among all ethnic groups. McNeill et al. (3988) found that future intentions to smoke increased the odds of starting to smoke by a factor of 244 and was the strongest predictor. of change in smoking status after current behavior (hav- ing tried smoking) and gender were entered into the analysis. In the Chassin et al. (1984) longitudinal study, behavioral intentions were "significant predictors of fu- ture smoking transition in all subgroups, accounting for between 1.9 percent and 10.2 percent of the variance in transition. . . . In fact, behavioral intentions were typi- cally the most important single predictor of future tran- sition" (p. 237). Intentions to smoke appear to be a particularly strong predictor of future smoking for those who have already tried smoking. Shean (1991) found that inten-' tions to smoke a "next cigarette" among 14-year-old Western Australians predicted smoking eight years later. Conrad, Flay, and Hill (1992) found that in eight of nine prospective studies of young adolescents, the intention to smoke was significantly associated with onset. Be cause of the strength of this association, severat reseamh- ers have used intentions to smoke as an outcome measure in their studies, especially in populations (such as p* adolescents) where smoking prevalence is low relative to adolescents' intentions to smoke. Intentions to begin smoking seem a much more reliable predictor of future behavior than do intentions to quit smoking (see "Adult Implications of Adolescent Smoking" in Chapter 3). Present Smoking Status Any cigarette use places an adolescent at higher risk for subsequent use and for further progression through the stages of smoking behavior. Conrad, Flay, and Hill (1992) document seven prospective studies in which prior experience with, or exposure to, smoking predicted tobacco use. McNeill et al. (1988) found that the act of having tried smoking was the most predictive factor in initiation and that it more than quadrupled their study participants' odds of taking up smoking. Collins et al. (1987) found that prior smoking behavior was the most important predictor of future smoking over a 2.5- year interval. Even though the physiological effects of the fust tries are mostly adverse (unpleasant taste, cough- ing headache, nausea, dizziness) (Hahn et al. 19901, those who persist report incmasingiy positive reactions (pleas- ant taste, euphoria, alertness, relaxation, curbing of ap petite) and develop tolerance (experience fewer unpleasant sensations) (Flay 1993). Stein, Newcomb, and Bentler (unpublished data) reported a more estab- lished pattern of cigarette use among young adults than among adolescents. In their study, the standardized regression coefficient of prior smoking for smoking be- havior between Year 1 and Year 5 (youth in junior high and high school age groups) was 0.43, yet from Year 9 to Year 13 (young adulthood) it was 0.82. The authors suggest that in early adolescence, some cigarette triers never fully develop a pattern of smoking but by late adolescence, the addictive properties of cigarette use figure prominently in behavior formation. These find- ings underscore the need for antismoking efforts to focus on preventing initial tries, on discouraging transitions to more regular smoking, and on encouraging early cessa- tion (Leventhal, Fleming, Glynn 1988; Kelder 1992). Summary of Psychosocial Risk Factors for Cigarette Smoking Some clear convergence of research findings emerges from this review, a summary of which is high- lighted in Table 1. Table 3 provides a second summary of supportive and unsupportive findings from the Conrad, Play, and Hill (1992) review of 27 prospective studies; for the most part, this summary table is consis- tent with Table 1. Among the so&demographic factors, age is the risk factor consistently linked with onset in early adolescence; ages 11 through 15 (seventh through ninth grades) am the peak age group for first trial and experimentation. Cigarette smoking clearly has social meanings that are attractive to many young and vuhter- able identityseeking adolescents. This age factor is even more pronounced when linked with SES, another im- portant so&demographic risk factor for smoking onset. Altema tive health-enhancing avenues for independence and identity may be less readily available to adolescents from lower SES families, especially those adolescents who live in a single-parent home. Limited by fewer opportunities for healthy development and parental su- pervision, lower-SES youth are generally at greater risk to begin smoking. The gender difference, another major factor, is no longer evident, although the meanings of 104 Psychosocial Risk Factors preventing Tobacco Use Among Young People cigarette use and the pathways to regular use may vary by gender. Finally, differences by ethnic group do not appear to show a consistent pattern across communities, particularly when income level and cigarette availability are considered. The review of so&demographic factors thus concludes that a young adolescent from a low-SES family is at highest risk to begin smoking. Proximal environmental factors, such as the influ- ence of peers, friends, and siblings, play a powerful role in the initiation of adolescent smoking. Smoking initia- tion appears to be a component of peer associations and peer bonding in adolescence, as peer groups establish shared behaviors to differentiate themselves from other adolescents and from adults. Adolescents usually try their first cigarettes with their peers; peer groups may subsequently provide expectations, reinforcement, and opportunities for continuation. The influence of peers seems to be particularly potent in the stages of smoking that precede regular use; in later stages, personal and pharmacological factors appear to predominate. Data on the influence of parental smoking are not as compelling as those on peer influence; only about half of the prospective studies show a clear predictive rela- tionship. The influence of parental smoking appears to be strongest for whites and females, particularly in the early stages of smoking onset. This review suggests that parental influence might include other important fac- tors, such as parents' approval or disapproval of smok- ing, their involvement in freetime supervision, their manner and extent of communication on health-related matters, or their promotion or nonpromotion of aca- demic achievement for their children. Lastly, young people are exposed not only to role models but also to the consequences of the behavior of these role models; having a parent who smokes might even serve to deter an adolescent from smoking if the parent is struggling with cessation or displays the health consequences of tobacco use. How adolescents perceive their social environment also influences their smoking behavior. Adolescents overestimate the number of young people and adults who smoke, and those with the highest estimates are more likely to become smokers. In addition, young people are more likely to smoke if they feel that their peers approve of smoking, and particularly if adults do not seem to disapprove. In each of these cases, the perceived environment could accurately reflect the ac- tual environment. Those who begin to smoke may actu- ally be exposed to more role models who smoke, more peers who approve of smoking, and fewer adults who disapprove than those who never begin to smoke. Families in which parents are considered to be generally concerned and supportive, or in which the children are involved in family decisions, are home environments in which adolescents are less at risk for smoking initiation. Parental strictness and parental approval or disapproval of smoking have indirectly and inconsistently predicted initiation and are there- fore less influential on adolescent smoking behavior than the general family environment. The research on parental skills in coping with adolescent smoking is limited and warrants further investigation. The behavioral factors examined were consistently associated with the initiation of cigarette smoking. Pat- terns of behavior that are associated with smoking in- clude alcohol and drug use, risk-taking and rebellious actions, and involvement in peer groups in early adoles- cence. Patterns of behavior that are associated with les`s risk of smoking include academic achievement, involve- ment in sports (for females), hea$hy eating and physical activity patterns, and the ability to resist offers of ciga- rettes. Thus, encouraging and providing opportunities for health-enhancing activities and academic achieve- ment might, by fulfilling some of the needs that smoking apparently meets for adolescents, prevent some young people from trying their first cigarette. The personal factors-those most proximal to the individual and to the immediate decision to smoke a cigarette-reflect, in part, the adolescent's intemaliza- tion of the social environment. An adolescent's knowl- edge of the health consequences of smoking is a poor predictor of subsequent cigarette use, although smoking risks that are personalized appear to be important. More significant predictors include the meanings, the perceived positive functions, and the expected utility of cigarette use. These aspects are linked to having a positive social image, bonding with peers, and being "mature'`-all of which are particularly socially relevant for adolescents. Compared with nonsmoking adolescents, those who begin to smoke appear to have lower self-images and lower self-esteem; for them, smoking becomes a self- enhancement mechanism. Similarly, self-efficacy toward avoiding cigarettes seems particularly linked with the ability to resist cigarette offers from peers. Of the person- ality variables, symptoms of depression, helplessness, aggression, pessimism, and a limited ability to conceptu- alize the future were all found to be smoking-predictive in a small number of studies. The most predictive per- sonal factors were those linked to the social environ- ment, to peers, and to the meanings of cigarette smoking learned in youth. Intentions to smoke and prior experimentation with cigarettes strongly predict subsequent smoking. The adverse physiological reactions to first tries at smoking wane with repetition, and tolerance levels to nicotine increase. Adolescents who smoke are more likely than nonsmokers to discount the negative health consequences of smoking, report positive functions of smoking, and Psychosocial Risk Factors 105 Surgeon General's Report perceive that their peers are smokers. The shift from social to more personaI reasons for smoking is associated with increasing nicotine dependence and addiction. Several other factors that influence smoking initiation are not covered in this chapter. First, the com- bined influence of tobacco advertising and promotion represents a powerful environmental risk factor (see Chapter 5). Second, cultural or community-level re- search on the causes of smoking onset is decidedly lim- ited. In particular, the effect of taxation, of restrictions to public smoking, of vending machine regulations, and of limiting access to tobacco for underage buyers needs to be addressed prospectively (Chapman and Bloch 1992; Sweanor et al. 1992; see Chapter 6). Third, even at the school level, smoking prevalence rates have been shown to be partly attributable to attendance at a particular school and to school smoking policies (Best et al. 1984; Semmer, Lippert, et al. 1987; Penk et al. 1989; Santi et al. Initiation of Smokeless Tobacco Use 1990-91; see "Smoking Restrictions in the School" in Chapter 6). Still, which aspects of schools contribute to smoking onset-whether their rules, consistency of rule enforcement, grade structure, or discipline procedures- need to be studied. These distal environmental factors partly determine the meaning for, and acceptability of, cigarette use at a community level, determine the ease or difficulty with -which adolescents can obtain tobacco, and reinforce or inhibit the continuation of use into adult- hood. Proximal factors are strong determinants of use once the meaning of-smoking is established and access to cigarettes is possible. Therefore, the more distal risk factors might be considered the proper targets of in- tervention research efforts, which should test the po- tency of these factors and provide the clear community-level message that cigarette smoking among the young is unacceptable. Compared with the research literature on smoking initiation, the knowledge base on smokeless tobacco initiation is modest. Far fewer longitudinal stud- ies have been conducted. For the most part, research efforts on smokeless tobacco have been crosssectional; a few have also been guided by behavioral theory. None- theless, a number of methodologically sound studies provide knowledgeabout the risk factors associated with the initiation of smokeless tobacco use. In parallel with the research on cigarette smoking among young people, sociodemographic, environmental, behavioral, and per- sonal factors have all been explored as correlates of smoke less tobacco use. With only a few exceptions, the consistency of the findings with those found for cigarette smoking suggests that both smoking and the use of smokeless tobacco products share a common causality as well as similar fmctions and meanings for young people. Sociodemographic Factors in the Initiation of Smokeless Tobacco Use National survey data on the demographics of smokeless tobacco Use are presented in detail in Chapter 3 (see "Recent Patterns of Smokeless Tobacco Use") and are only summa rind here. These data clearly indicate that smokeless tobacco use among young people is par- ticularly prevalent among non-Hispanic white males. The three youth surveys that assessed smokeless tobacco prevalence (that is, use during the month preceding the survey) also found that males were 10 to 15 times more likely than females to use smokeless tobacco. Although nationally representative data on American Indian and Alaskan Native youth are not available, community- level studies of these populations have xqorted high rates of weekly smokeless tobacco use among both males (43 percent) and females (34 percent), even at very young ages (Schinke et al. 1987,1989; Bruerd 1990). The Monitoring the Future Project survey, a na- tional survey of high school seniors, indiated that 54 percent of males had used smokeless tobacco. Among those, 23 percent first used smokeless tobacco before or during the sixth grade, and over 53 percent first used it before or during the eighth grade (see "Grade When Smokeless Tobacco Use Beg%&' in Chapter 3). Data from a number of other recent surveys suggest that early adolescence is the peak age for first using smokeless tobacco (Schaefer et al. 1985; US Department of Health and Human Services IUSDHHSI 1986; Ary, Lichtenstein, Severson 1987; Ary et al. 1989; Riley, Barenie, Myers 1989; Brownson et aL 1990; Riley et al. 1990,1991). Limited evidence suggests that the following so&demographic factors may also be related to higher rates of smokeless tobacco use among youth: one or no parenk in the household (Jones and Moberg 1988; Murray et al. 1988; see "So&demographic Risk Factors for 106 Psychosocial Risk Factors Prevedng Tobacco Use Among Young People Smokeless Tobacco Use" in Chapter 3); lower parental education (Bauman, Koch, Lenk 1989; Botvin, Baker, To&u 1989); blue-collar parental occupation (Burke et al. 1989; Elder, Molgaard, Gresham 1988; Novotny et al. 1989); and rural environment (Olds 1988; botvin, baker, Tortu 1989; Rouse 1989; Lisnerski et al. 1991; see "So&demographic Risk Factors for Smokeless Tobacco Use" in Chapter 3). As is reported in Chapter 3 (see "Current Use of Smokeless Tobacco"), prevalence varies among regions and is somewhat lower in the Northeast than in other regions. Environmental Factors in the Initiation of Smokeless Tobacco Use Factors That Influence Acceptability and Availability Ease of access to smokeless tobacco appears to be an important factor in initiation, and young people seem to have little trouble obtaining smokeless tobacco (USDHHS 1992a, CDC 1993). In interviews conducted by the Office of Inspector General WSDHHS 1986),90 percent of smokeless tobacco users in junior and senior high school reported that they purchased their own smokeless tobacco; 94 percent reported that although they were minors, it was either never or only rarely difficult for them to purchase smokeless tobacco. Conve- nience stores were the most frequent purchase site (55 percent); supermarkets and grocery stores accounted for an additional 33 percent of sales. barovich et al. W9.l) found that 50 percent of store personnel were willing to sell to minors. In another study (Leopardi et al. 19891, junior high school students reported that their leading sources of smokeless tobacco were friends (43 percent) and direct store purchase (30 percent); senior high school students' chief sources were direct purchase (62 percent) and friends (25 percent). In a recent study in Texas, minors successfully purchased smokeless tobacco in 59 percent of stores selling the product (CDC 1993). Interpersonal Factors Parental Use As in the research on cigarette smoking, the evi- dence depicts either a modestly positive or no significant association between parental use of smokeless tobacco and adolescent use. The only prospective study that examined parental use found no link to onset or contin- ued use of smokeless tobacco among youth (Ary, Lichtenstein, Severson 1987). However, several cross- sectional studies have reported significant relationships between concurrent use by parents and youth (Cohen et al. 1987; Hall and Dexter 1988; Colbom, Cummings, Michalek 1989; Glover et al. 1989; Brownson et al. 1990). Bauman, Koch, and Lentz (1989) found that an adoles- cent was more likely to use smokeless tobacco if the father did, although there was an interaction with the level of the father's education. Two cross-sectional stud- ies found no significant association between con- current use of.smokeless tobacco by parents and adoles- cent offspring (Chassin et al. 1985; Ary, Lichtenstein, Severson 1987). Sibling Use The evidence from cross-sectional studies gener- ally supports a relationship between a sibling's use of smokeless tobacco and an adolescent's use. However, one prospective study did not fjnd significant sibling relationships (Ary, Lichtenstein, Severson 1987), and an- other study found no effect for "older family members" (Chassin et al. 1985). The sole longitudinal study did not find that sibling use was related to adolescent onset (Ary, Lichtenstein, Severson 1987). Peer Use Although a substantial amount of cross-sectional research has examined the use of smokeless tobacco by peers, only two longitudinal studies have been pub lished. Every cross-sectional study found that peer use was significantly related to adolescent use (Cohen et al. 1987; Hall and Dexter 1988; Lucas and Christen 1988; Glover et al. 1989; Leopardi et al. 1989; Riley, Barenie, Myers 1989; Brownson et al. 1990, Hunter, Vizelberg, berenson 1991). Peer use of smokeless tobacco was related to the onset of adolescent use at the 9-month follow-up in one longitudinal study (Ary et al. 1989) but not in another study (Ary 1989) at the 6- and K&month follow-up times. However, peer use was found to be related to continued use among initial daily users of smokeless tobacco at 6, 9-, and 12-month follow-ups (Ax-y, Lichtenstein, Severson 1987; Ary 1989). Perceived Environmental Factors Norms Current evidence indicates that most adolescents who use smokeless tobacco perceive that this behavior is socially acceptable. The Office of Inspector General (USDHHS 1986) reported the following findings from a survey of male adolescents who used smokeless to- bacco: o 86 percent perceived that most or some students at their school approved of smokeless tobacco use. Psychosocial Risk Factors 107 o 98 percent said their best male friends either approved of, or were neutral toward, their smokeless tobacco use. o 93 percent said their parents knew of their smokeless tobacco use. o 68 percent said their fathers and 45 percent said their mothers approved of, or were neutral toward, their smokeless tobacco use; o 91 percent said their brothers and 71 percent said their sisiers either approved of, or were neutral toward, their smokeless tobacco use. 87 percent listed their home as a setting where they regularly used smokeless tobacco. 43 percent whose dentist knew of their use were not advised by that professional to quit. 51 percent said their coaches either approved of, or were neutral toward, their smokeless tobacco use. These findings were replicated in the 1992 Office of the Inspector General study on Spit Tobacco and Youth (USDHHS 1992b). The adolescents in this study who used smokeless tobacco said that the greatest influences on their trying smokeless tobacco were peer pressure and other family members' use. The majority of these young users felt their parents would agree that their using smokeless tobacco was preferable to smoking ciga- rettes (USDHHS 1992b). In another study, only 14 percent of smokeless tobacco users reported that their father disapproved of their smokeless tobacco use, whereas 60 percent said their mother disapproved (Marty, McDermott, Williams 1986). WilIiams et al. (1986) found that 55 percent of smokeless tobacco users indicated that their parents dis- approved of their use. in a study by Ary et al. (19891, only 13 percent of daily smokeless tobacco users re- ported that their dentist had said anything to them about their use. Brubaker and Loftin (1987) found that smokeless tobacco users reported greater peer accep- tance of, and less parental opposition to, their use than did nonusers. Social Support Chassin, Presson, and Sherman (1988) examined the relationship between family social support and current use of smokeless tobacco. Three cross-sectional analyses found no pattern of relationships between smokeless to- bacco use and perceived parental expectations (for success or academic accomplishment), parental supportiveness, Surgeon Generals Repott parental strictness, agreement between parents, parent- peer agreement, or the adolescent's reported motivation to comply with parents. Similarly, two sets of analyses examining one-year prediction of smokeless tobacco on- set found no statistically significant effects for the same set of factors, although the statisti& Rower to detect such effects was minimal because the sample contained few cases of smokeless tobacco onset. Parental Reaction to Smokeless Tobacco Use Parents appear to be more accepting of smokeless tobacco use than of cigarette smoking. About 40 percent of high school smokers reported that their parents knew about their smoking, whereas smokeless tobacco users reported that 71 percent of their iarents knew of their use (Chassin et al. 1985). Similarly, young people who did not use tobacco reported that their parents and peers were more accepting of smokeless tobacco use than of smoking (Chassin et al. 1985; Ary et al. 1989). These findings suggest that adolescents may begin using smoke- less tobacco partly because they perceive that it is less deviant than smoking or other drug use and therefore is more likely to be accepted by their peers and parents (Hahn et al. 1990). Some research evidence indicates that the antici- pated parental response to an adolescent's use of smoke less tobacco is related to that youth's likelihood of using smokeless tobacco. Riley, Barenie, and Myers (1989) found that high school students' anticipation of their parents' response was highly predictive of the first trial of smokeless tobacco and of the level of continued use. Brubaker and Loftin (1987) found that adolescents who did not currently use smokeless tobacco but who intended to become users reported that it would be unlikely that their parents would respond by taking away their privileges, reprimanding them, becoming an- gry, expressing disappointment, or prohibiting them from continued use. These youth also reported that it was likely that their parents would ignore their smokeless tobacco use. Behavioral Factors in the Initiation of Smokeless Tobacco Use Academic Achievement For males, smokeless tobacco use was related to poor academic performance (Jones and Moberg 1988) and to a low grade point average (Brownson et al. 1990). The NIDA national household survey indicated that for males, the prevalence of daily use of smokeless tobacco was highest among school dropouts (13 percent) and lowest among college students (6 percent) (Rouse 1989). 108 Psychosocial Risk Factors Proven ting Tobacco Use Among Young People Smoking as a Risk Factor for Smokeless Tobacco Five longitudinal studies examined the prospec- tive relationships between cigarette smoking and the onset or continued use of smokeless tobacco Wy, Lichtenstein, Severson 1987; Dent et al. 1987; Murray et al. 1988; Ary 1989; Sussman et al. 1989). (The relation- ship between smokeless tobacco use and subsequent cigarette smoking is reviewed later in this chapter.) In a longitudinal study of eighth graders, Dent et al. (1987) reported that smoking status at baseline predicted the onset of smokeless tobacco use one year later. Twenty- nine percent of regular smokers at baseline-but only 6 percent of those who had never smoked-reported smokeless tobacco onset at follow-up. Ary, Lichtenstein, and Severson (1987) used disaiminant analysis to iden- tify predictors of the onset of smokeless tobacco use nine months after smoking onset among 7th,9th, and 10th graders. The disaim&nt function accounted for .11 percent of the variance, and having tied smoking was an important predictor, correlating at 0.64 with the dis- aiminant function. Jn a similar study using a separate sample of 7th, 9th, and 10th graders in Oregon, smoking did not significantly predict smokeless tobacco onset at 6-month or 12-month follow-ups (Ary 1989). Another longitudinal study found general support for the influ- ence of smoking on seventh graders who had tried smoke less tobacco (Murray et al. 1988). Longitudinal analysis of one-year follow-up data from two other samples of seventh graders indicated that both males and females exhibited a fairly consistent relationship between, the onset of smokeless tobacco use and pretest smoking thsman et al. 1989). Three of the longitudinal studies cited above also examined the prospective relationship between cigarette smoking and continued use of smokeless tobacco among adolescents. Ary, Lichtenstein, and Severson (1987) found that baseline smoking did not predict frequency of later smokeless tobacco use at nine-month foIlow-up. In a separate study, Ary (1989) examined these relationships and found that frequency of smoking was related to continued daily smokeless tobacco use at 1Zmonth follow-up but not at 6month follow-up. A 24month follow-up study of ninth graders also found general support for the infhrence of smoking on later use of smokeless tobacco (Murray et al. 1988). Although the findings from these thr& prospective studies are incon- clusive, numerous studies `&port significant concurrent relationships between smoking and smokeless tobacco use. The degree of statistical power exhibited by these relationships varied widely, but every study found at least one significant association between smokeless to- bacco use and smoking. Other Adolescent Behaviors Twelve studies fairly consistently indicated that smokeless tobacco use is related to concurrent use of alcohol and marijuana Whtenstein et al. 1984; Ary, Lichtenstein, Severson 1987; Burke et al. 1988,1989; Jones and Moberg 1988; Murray et al. 1988; Ary 1989; Riley, Barenie, Myers 1989; Rouse 1989; Sussman et al. 1989; Riley et al. 1991; Stevens et al. 1991). One of these studies CGssman et al. 1989) found that seventh- and eighth- grade females showed no relationship between having tried smokeless tobacco and concurrently using alcohol, but two of four samples with male subjects showed significant relationships. Only three studies examined the prospective relationships between smokeless to- bacco use and the use of alcohol and marijuana. In one study, the onset of smokeless tobacco use among those who had not used at baseline was related to marijuana use but not to alcohol use (Ary, Lichtenstein, Sever-son 1987). In a separate study, initial use of alcohol or mari- jrtana did not predict onset of smokeless tobacco use at 6- month follow-up, but initial alcohol use predicted smokeless tobacco use at 12-month follow-up (Ary 1989). In another 1Zmonth longitudinal study, onset of smoke less tobacco use among those who at baseline had never used smokeless tobacco was predicted by initial alcohol use in one of two samples of seventh-grade females but not in two samples of males (Sussrnan et al. 1989). Taken together, there is some evidence that prior use of either alcohol or marijuana is related to subsequent onset of smokeless tobacco use and to continued useof smokeless tobacco among daily users. Several studies suggest that adolescents who use smokeless tobacco are more likely to use multiple drugs than are adolescents who do not use smokeless tobacco. Ary, Lichtenstein, and Severson (1987) found that among male adolescents who reported use of smokeless to bacco, cigarettes, alcohol, or marijuana in the week pre- ceding the survey, 43 percent (47 percent in Arfs separate study [19891) indicated that they used more than one of these substances during that week The percentage of daily users of smokeless tobacco who reported use of alcohol during the preceding week was particulariy high (76 percent in Ary, Lichtenstein, and Severson's study [1987J and 74 percent in Ary's separate study 119891). Among daily smokeless tobacco users, 83 percent in Ary, Lichtenstein, and Severson's study (1987) (80 percent in Ary's 1989 study) also reported using a drug other than alcohol, a fact suggesting that daily smokeless to- bacco users are particularly likely to be multiple drug users. Psychosocial Risk Factors 109 Surgeon Gem-al's Report Smokeless Tobacco Use as a Risk Factor for Smoking, Alcohol, and Other Drug Use Although the known Literature indicates that the use of cigarettes and other drugs. is a risk factor for smokeless tobacco use, several studies also indicate that the converse is true; that is, smokeless tobacco use is a risk factor for the onset and maintenance of cigarette smoking and for the use of alcohol and marijuana (see "Smokeless Tobacco Use and Other Drug Use" in Chap ter 3). Ary, Lichtenstein, and Severson (1987) examined the prospective relationship between smokeless tobacco use and the onset of the use of cigarettes, alcohol, and marijuana at nine-month follow-up. Smokeless tobacco users were found to be more likely than nonusers to begin using cigarettes (22 percent vs. 7 percent), alcohol (18 percent vs. 7 percent), and marijuana (37 percent vs. 18 percent). These findings were replicated in Ary's. (1989) 12-month follow-up study of a separate sample. Smokeless tobacco users were significantly more likely than nonusers to report smoking cigarettes (6 percent vs. 0.5 percent), drinking alcohol (29 percent vs. 12 percent), and smoking marijuana (12 percent vs. 2 percent). Similarly, smokeless tobacco users were more likely than nonusers to increase their use of other drugs. A greater proportion of smokeless tobacco users than of nonusers reported increased use (in the week preceding the survey) of cigarettes (18 percent vs. 8 percent), alco- hol (34 percent vs. 20 percent), and marijuana (20 percent vs. 8 percent) (Ary, Lichtenstein, Severson 1987). The 1989 study replicated these findings for each substance: cigarettes (7 percent vs. 2 percent), alcohol (25 percent vs. 13 percent), and marijuana (15 percent vs. 2 percent) (Ary 1989). Several studies provide additional evidence for the progression from smokeless tobacco to other drugs. In one, decreases in smokeless tobacco use were accompanied by increases in cigarette smoking (Hunter et al. 1986). In a different longitudinal study, smokeless tobacco users were more likely to report cigarette smok- ing at a two-year follow-up (67 percent) than were non- users (14 percent) (Schinke et al. 1986). A study of undergraduates found that switching from smokeless tobacco to cigarettes was a more Likely progression than the converse (Glover, I.&in, Edwards 1989). Risk Taking and Rebelliousness Although smoking is associated with rebellious- ness and unconventionality, several studies have found no such association for smokeless tobacco use. A signifi- cant but modest relationship has been found between smokeless tobacco use and risk taking. In one of the few longitudinal studies of smokeless tobacco use, Dent et al. (1987) found that among eighth graders, current risk taking predicted the onset of smokeless tobacco use one year later. In another study, a significant relationship was reported between seventh-grade students' smoke- less tobacco use and risk taking (Botvin, Baker, Tortu 1989). Studies with high school students found that risk taking was related to trying smokeless tobacco but not to the level of smokeless tobacco use (Riley, Barenie, Myers 1989; Riley et al. 1991). In two of eight replication samples in another study, risk taking was a significant correlate of trying smokeless tobacco (Sussman et al. 1989). Participation in Athletics Given the number of professional athletes who use smokeless tobacco, and given the associated advertising efforts by smokeless tobacco companies, youth who par- ticipate in athletics would seem likely to be at greater risk of using smokeless tobacco than nonparticipants. Cur- rent studies have mixed findings about this possible relationship. Although 28 percent of predorninantLy white Little League baseball players (aged 12 or less, N = 1,141) in southeast Texas believed that more than half of profes- sional baseball players use smokeless tobacco, this belief was not strongly associated with use of smokeless to- bacco among these youth (Evans, Raines, Getz 1992). Similar findings on a stratified random sample of rumI and urban youth in grades one, three, five, and seven were reported in North Carolina (Lisnerski et al. 1991). In a one-year longitudinal study of seventh graders, sports participation did not predict onset of smokeless tobacco use in two samples of males and in one of two samples of females (Sussman et al. 1989); for the other sample of seventh-grade females, the relationship was positive but modest. Sussman et al. (1990) reported that self-identified "dirts" (i.e., "heavy metal" music enthusi- asts and marijuana users) and "skaters" (i.e., skateboard- ers and surfers) were more likely to be currently using smokeless tobacco than were "jocks/athletes." Another study of high school students yielded inconclusive re- sults (Riley, Barenie, Myers 1989). On the other hand, Ringwalt (1989) found that llth- and 12th~grade athletes (students who played on school teams) were more likely than nonathletes to have used smokeless tobacco, to have used smokeless tobacco in the preceding 30 days, and to perceive fewer (if any) health risks for smokeless tobacco use. Jones and Moberg (1988) found that fre quency of smokeless tobacco use was related to partici- pation in team sports. Glover et al. (1989) found that smokeless tobacco use among U.S. college students was related to participation in organized sports. Taken to- gether, the current evidence is inconclusive and war- rants further investigation that might consider team rules regarding smokeless tobacco use, coaches' use of smoke- less tobacco or attitude toward team members' use, and parents' degree of involvement in the team. 110 Psychosocial Risk Factors preventing Tobacco Use Among Young People Personal Factors in the Initiation of Smokeless Tobacco Use Knowledge of Long-Term Health Consequences Because the long-term health consequences of smokeless tobacco use have not been as widely commu- nicated as those of smoking, knowledge of these conse quences is potentially an important predictive factor for smokeless tobacco use. `Most youth appear to be aware that smokeless tobacco use can be harmful to health, but most smokeless tobacco users do not perceive their own risk to be great. In interviews with smokeless tobacco users, 80 percent of junior high school and 92 percent of senior high school users acknowledged that smokeless tobacco use can be harmful, but about 60 percent of the junior high users and 40 percent of the senior high users believed that there was no risk or only slight risk in regular smokeless tobacco use KJSDHHS 1986). A study of 7th- through 10th~graders found that 31 percent of daily users of smokeless tobacco believed that there was very little health risk associated with this use (Ary, Lichtenstein, Severson 1987). Similarly, only 40 percent of 7th- through 12th-grade students in another sample perceived smokeless tobacco use as very harmful (Schaefer et al. 1985). Marty, McDermott, and Williams (1986) reported that 35 percent of high school students who use smokeless tobacco believed that such use had little or no effect on their health. Many youth appear to believe that smokeless to- bacco use is much safer than cigarette use. Schaefer et al. (1985) found that 77 percent of smokeless tobacco users perceived smoking to be very harmful, whereas only 40 percent perceived smokeless tobacco use as very harmful. Another study reported that 86 percent of fifth- and sixth-grade smokeless tobacco users be- lieved that smoking would hurt their health, but only 33 percent believed this of smokeless tobacco use (Schinke et al. 1986). Ary et al. (1989) found that when smokeless tobacco users were asked why they pre- ferred smokeless tobacco to cigarettes, they most often gave "lower health risk" as the reason. Users of smoke- less tobacco are more likely than nonusers to perceive that smokeless tobacco is a comparatively safe altema- tive to cigarette use (Chassin et al. 1985; McDermott and Marty 1986; Boyle 1989; Glover, Laflin, Edwards 1989; Brownson, DiLorenzo, Van Tuinen 1990; Brownson et al. 1990; Lisnerski et al. 1991). A number of studies have examined the relation- ship between concurrent smokeless tobacco use and health knowledge and beliefs about smokeless tobacco, but none of these studies have examined the prospective relationship. Most of these studies show that youth with more health knowledge of, or greater beliefs in, the risks of smokeless tobacco use are indeed less likely to use smokeless tobacco. Three studies reported that having tried smokeless tobacco was related to lack of health knowledge and beliefs (Cohen et al. 1987; Riley, Barenie, Myers 1989; Riley et al. 1991); only one study that exam- ined this possible link failed to find such a relationship, and that study involved very young subjects (first through seventh graders) (Lisnerski et al. 1991). Mul- tiple studies have reported that health knowledge and beliefs were significantly related to various categories of smokeless tobacco use (Boyle 1989; Polcyn et al. 1991), current smokeless tobacco use (Chassin et al. 1985; Colbom, Cummings, Michalek 1989; Glover, Laflin, Edwards 1989; Marty, McDermott, Williams 19861, level or amount of smokeless tobacco use (Riley, Barenie, Myers 1989; Riley et al. 1991), or daily smokeless tobacco use (Ary, Lichtenstein, Severson 1987). In only two studies was no relationship found between health knowledge and beliefs and smokeless tobacco use (Brownson et al. 1990; Lisnerski et al. 1991). Functional Meanings In a study of seventh- and eighth-grade students, favorable personal attitudes toward smokeless tobacco use were significantly related to concurrent use of smoke less tobacco 18 years) in four states: Arizona (N = 294), Pennsylvania (N = 2911, Texas (N = 3031, and Michigan (N = 98) Advertising of cigarettes should be banned in newspapers, magazines, and outdoor posters or billboards. Tobacco companies should be prohibited from distributing free tobacco samples on public property or through the mail. Agreement across the four states sampled: 61%-69% 73%-81% Tobacco companies should be prohibited from sponsoring sports events or advertising their products at these events. 49%59% California Department of Health Services 1990 (California Department of Health Services 1991) Telephone survey of a random sample of adults (aged Z 18 years) in California (N = 6,600) Do you think advertising of tobacco products on outdoor billboards should be allowed or banned? Do you think advertising of tobacco products through newspapers and magazines should be allowed or banned? 54% favored a ban (42% smokers; 62% nonsmokers) 49% favored a ban (38% smokers; 57% nonsmokers) Do you think sponsorship of sporting 52% favored a ban or cultural events by tobacco companies (39% smokers; 61% should be allowed or banned? nonsmokers) Do you think that distribution of free cigarettes and tobacco products on public property should be allowed or banned? 75% favored a ban (62% smokers; 84% nonsmokers1 Do you think that distribution of free tobacco samples or coupons to obtain free samples by mail should be allowed or banned? 67% favored a ban (52% smokers; 78% nonsmokers) *COMMIT = Community Intervention Trial for Smoking Cessation. 128 Prevention preventing Tobacco Use Among Young People Data collected in a 1992 national telephone poll (N = 1,200) of adults (Louis Harris and Associates 1992) suggest that a predominant belief in the individual's fight to smoke coexists with a less predominant concern about the persuasive power of tobacco advertising. An overwhelming majority (87 percent) of respondents agreed with the proposition that "to smoke or not to smoke is a personal decision that adults should be free to make for themselves." On the other hand, 68 percent favored a ban on tobacco ads in newspapers, in maga- zines, and on billboards; 73 percent said they would support an initiative to require stronger warning labels on cigarette packages; and 83 percent would favor legis- lation banning tobacco ads targeted at teenagers. Three quarters of smokers themselves supported a ban on tobacco ads targeted at teenagers. The survey report concludes that "even smokers see smoking as something to be discouraged, especially where teenagers are concerned" (p. 39). Restrictions on the Sale of Tobacco Products to Minors Public opinion strongly favors measures to discour- age tobacco sales to minors (persons under the age of 18). A 1962 national Gallup personal interview survey (Gallup Organization 1962) found that 79 percent of adults sup ported the idea that there should be a law against selling cigarettes to people under 16 years old. According to the 1964 AU'IS (U.S. Department of Health, Education, and Welfare JLJSDHEWJ 1%9), only 9 percent of adults thought that sales of cigarettes to young people under a certain age should not be against the law. Today, all states have laws prohibiting the sale of cigarettes to persons under 18 years old (CDC, OSH, unpublished data). On July 10, 1992, Congress passed Public Law 102-321, the Alcohol, Drug Abuse, and Mental Health Administration (ADAMHA) Reorganization Act, which contained Section 1926, providing for the enforcement of minors' access legislation in all states receiving funding for the prevention and treatment of substance abuse. These provisions required funded states to enforce legis- lation prohibiting the sale or distribution of tobacco prod- ucts to individuals under the age of 18. Enforcement included yearly random, unannounced inspections as well as annual reports to the Secretary of Health and Human Services describing the state's enforcement ac- tivities for that year, the extent of success in reducing the availability of tobacco to children under 18, and enforce ment strategies to be used in the next year for which funding was being sought. By June 1993,49 states and the District of Columbia had passed legislation in com- pliance with Section 1926, prohibiting the sales and distribution of tobacco products to children under the age of 18. (Virginia restrictions applied only to sales of tobacco products.) Most people do not believe that laws prohibiting the sale of tobacco to minors are adequately enforced, and the overwhelming majority of both smokers and nonsmokers support stronger measures to limit minors' access to tobacco. The 1989 SAVES (Marcus et al., in press) found that 8 out of 10 adults felt it was "very easy" or "somewhat easy' for teenagers to buy cigarettes near where they live (see `Factors That Influence Tobacco Acceptability and Availability' in Chapter 4). The over- whelming majority of respondents to this survey (86 to 92 percent) felt that there should be better enforcement of existing laws banning the sale of tobacco to minors, and most (83 to 88 percent) endorsed the idea that the laws should be strengthened. Results of a 1990 survey of California adults (California Department of Health Ser- vices 1991)provideasimilarpicture;76percentresponded negatively when asked, `Do you think the laws banning the sale of tobacco products to minors have been ad- equately enforced?" Several different surveys have tried to assess public opinion regarding specific types of legislative actions (e.g., licensing retailers and banning cigarette vending machines) to prevent minors' access to tobacco (Table 2). A 1987 survey of adults in Minnesota (Forster etal.l991)foundthat75percentfavoredapolicywhereby retailers would lose their tobacco licenses if they sold cigarettes to minors. Two-thirds of adult participants in the 1989 COMMlT survey (CDC 1991a) agreed with the statement, `Tobacco products should be as strictly con- trolled as alcohol products." The majority of respon- dents in this survey (from 77 to 93 percent) also agreed with the statement, `Merchants who sell tobacco to mi- nors should be fined." The 1989 SAVES (Marcus et al., in press) asked respondents in four states if they thought the sale of cigarettes through vending machines should be banned. Overall, between 60 and 68 percent of respondents fa- vored a ban on cigarette vending machines; smokers were much less likely than nonsmokers to support a ban (42 to 58 percent vs. 66 to 72 percent). The 1987 Minne sota survey (Forster et al. 1991) found that 57 percent of adults supported a policy eliminating all cigarette vend- ing machines; 80 percent favored a policy banning vend- ing machines in locations where teenagers gather. In the 1990 California survey (California Department of Health Services 19911, a majority of both smokers (74 percent) and nonsmokers (87 percent) favored the idea of ban- ning cigarette vending machines that are accessible to minors. A similar result was found in the 1989 COMMIT survey (CDC 1991a), wherebetween 76 and 89 percent of adults agreed with the statement, "Cigarette vending Prevention 129 Surgeon General's Report Table 2. Public opinion about different legislative actions to prevent minors' access to tobacco, United States, 1987- 1991 Source and year of survey Description of survey Questions or statements Responses American Cancer Society 1989 (Marcus et al., in press) Telephone survey of a random sample of adults (aged 2 18 years) in four states: Arizona (N = 294L Pennsylvania fN = 2911, Texas (N = 3031, and Michigan (N = 98) Do you think there should be laws to ban the sale of cigarettes through vending machines? Support for a ban across the four states sampled: 60%-68% California Department of Health Services (California Department of Health SeNiCes 1991) Telephone survey of a random sample of adults (aged 2 18 years) in California (N = 6,600) Do you think cigarette vending machines that are accessible to minors should be allowed or banned? 82% favored a ban (74%. smokers; 87% nonsmokers) `COMMIT = Community Intervention Trial for Smoking Cessation. machines should be eliminated in places where teens gather." Taxes on Tobacco Products Public opinion surveys consistently show that most people would support an increase in tobacco taxes over other taxes (such as income tax, sales tax, or gasoline tax) (Gallup Organization 1989,1990a, 1993; Hart Research Associates and Robert Teeter 199Oa, b, c; Yankelovich, Clancy, Shulman WOa, b; ACS 1992; Kleine 1993). Sur- veys conducted between 1989 and 1993 show strong support for raising taxes on tobacco and alcohol as a way of nzducing the federal budget deficit or to pay for health care reform (`Toner 19931 (Table 3). Support for raising tobacco taxes tends to increase when tax revenue is earmarked for specific purposes, 120 Prevention Preventing Tobacco Use Among Young Peopie especially for health and educational programs (Gallup cigarettes to pay for an expanded federal antidrug pro- &ganization 1993), such as those aimed at preventing gram. The same questions asked in 1990 found that 77 children from smoking or from using drugs. A 1989 percent supported raising cigarette taxes (Associated national survey sponsored by the Associated Press (Asso- Press/Media General 1990). The 1989 SAVES (Marcus et &ted Press/Media General 1989) found that 75 percent of al., in press) found that about twc&irds of adults favored adults supported increasing the federal excise tax on using an extra tax on tobacco to cover the cost of Table 3. Public opinion about increasing tobacco taxes, United States, 1989-1990 - Source and year of survey Description of survey Questions Responses Gallup Organization 1989 National personal Taking into account 64% favored raising ciga- interview survey with the amount each (tax) rette taxes by 16 cents per 2,048 adults (aged 2 18 would raise, and your pack; the only other tax years) opinion about these measure mentioned more taxes, which, if any, frequently was raising the would you favor as a tax on alcohol (69%) means of reducing the federal budget deficit? Hart Research Associates and Robert Teeter 1990a, b, c National telephone survey of a random sample of registered voters (January survey N = 1,510; May survey N = 1,007; July survey N = 1,555) * `,. ,.`.*;z,`:- ^ _ .- Let us suppose the January 1990: 78% favor government needed to May 1990: 83% favor raise taxes. Do you July 1990: 78% favor favor or oppose raising alcohol and tobacco taxes? Associated Press/ Media General 1989,199O National telephone survey of adults (aged 2 18 years) (September 1989 survey N = 1,071; May 1990 survey N = 1,143) ..,i. .;I ":-22i :b& To pay for a bigger September 1989: 75% favor federal antidrug May 1990: 77% favor program, would you support or oppose higher federal taxes on cigarettes? Preuen tion 121 Surgeon General `3 Report campaigns to reduce smoking. A 1987 national survey sponsored by the American Medical Association (Harvey and Shubat 1987) found that 79 percent of adults favored an increase in the tax on tobacco products if the money from the increase went to Medicare. A 1992 survey of Michigan adults (ACS 1992) found that 72 percent would support raising the state's cigarette excise tax if the addi- tional revenue would be targeted for health care and education. Interestingly, 58 percent of respondents to this survey claimed that they would vote for a candidate who supported the tobacco tax increase, whereas 27 percent would vote for a candidate who opposed the tax increase. Some relevant information on public opinion re garding tobacco taxes comes from a survey conducted in Canada, where tobacco taxes have increased sharply in the past decade. A December 1990 poll conducted for the Council for Tobacco-Free Ontario (Council for a Tobacco Free Ontario/Non-Smokers' Rights Association 1992) questioned Ontarians about their support for a substan- tial increase in the tobacco tax. Overall, 58 percent of Ontarians supported a Went per pack increase in the cigarette tax; this support did not change when respon- dents were informed that taxes currently accounted for 60 percent of the retail price of cigarettes. However, when respondents were told that higher tobacco prices could prevent children from starting to smoke, support for the tax increase climbed to 67 percent. Support was even higher when respondents were told of different ways to use revenues raised by the new tax, such as reducing the budget deficit (70 percent support), helping people quit smoking (78 percent support), and estabhsh- ing a fund to help prevent smoking among young people (84 percent support; 77 percent among smokers). Educational Efforts to Prevent Tobacco Use Among Young People School-Based Smoking-Prevention Programs Introduction Since the 1964 publication of the first Surgeon General's report on smoking and health (public Health Service [R-IS] 1964), smoking prevention has been recog- nized as a primary strategy for controlling smoking in the general population. The first report identified the diffi- culty that long-term adult smokers typically experience in their attempts to quit. The report thus advocated programs directed at educating high school and college students about the health hazards of smoking; in theory, school-based programs would interfere with the devel- opment of smoking behavior before smoking became firmly established. When the term "prevention" was applied to health- related issues in the 196Os, however, the concept referred not exclusively to school curricula but also to efforts to disseminate warnings about products and practices that public health professionals considered potential health hazards (Schwartz 1969). The approach to prevention research at that .time consisted of biomedical research to establish physiological mechanisms of smoking-related diseases, coupled with epidemiologic research to iden- tify etiologic characteristics of smokers. This research led, when appropriate, to the dissemination of findings and recommendations to the public. A proclamation and direct warning from the U.S. Surgeon General about the life-threatening characteristics of cigarette smoking was expected to convince smokers to quit and nonsmokers to avoid taking up the practice. Had this effect been the case, the concept of smoking prevention might never have amounted to mom than "spreading the word" to those segments of the population who had not yet re- ceived it. Unfortunately, nearly three decades later and despite monumental efforts to disseminate warnings, cigarette smoking remains the single most preventable cause of death and disease in our society WSDHHS 1989). This section reviews the evolution of the concept of smoking prevention since the 1960s and identifies av- enues for future progress in this area. Early Approaches to Smoking Education and Prevention In the 1960s and early 197Os, strategies to prevent the onset of cigarette smoking were often based on the premise that adolescents who engaged in smoking be- havior had failed to comprehend the Surgeon General's warnings on the health hazards of smoking (Thompson 1978). The assumption was that these young people had a deficit of information that could be addressed by pre senting them with health messages in a manner that caught their attention and provided them with sufficient justification not to smoke. Improvements in knowledge levels, or cognitive factors, would thus lead directly to changes in behavior. 122 Prevention Preventing Tobucco Use Among Young People fnformation Deficit Model Early prevention programs based on this informa- tion deficit model tried to heighten young people's aware ness and comprehension of the negative consequences of smoking. Programs based on this model used various educationaI methods to convey information, including books, pamphlets, posters, films, and lectures Chomp son 1978). Through images and messages often intended to arouse fear, these programs were designed to con- vince the adolescent audience that persons who smoke risk a variety of serious physical consequences through- out their lives, including an increased likelihood of pre- mature death in adulthood from cardiovascular disease or cancer. The underlying assumption of these information- focused programs proved to have limited grounding. Although expanded educational efforts in schools throughout the 1970s provided adolescents with various kinds of smoking-related information, this information alone did not deter them from beghming to smoke. Com- prehensive reviews published at that time concluded that smoking-prevention programs based on the infor- mation deficit approach were not effective (Thompson 1978;Goodstadt 1978). providing knowledgeof the health consequences of smoking is still an important task for public health, but this single strategy is not sufficient to change most young people's behavior. Affective Education Model The information deficit model did not take into account the complex relationship between knowledge acquisition and subsequent behavior (nor, as will be discus& later, did it consider the addictive nature of tobacco use). For example, cognitive factors are medi- ated by different personal variables, including changes in attitudes, beliefs, intentions, and perceived norms (M&rim 1%4; Fishbem 1%7J. To rectify the shortcom- ings of information-focused interventions, alternative smoking-prevention approaches that evolved during the 1970s tried various forms of motivational or affective education. These approaches, which came to be referred to collectively as the affective education model, were based on the assumption that adolescents smoke ciga- rettes because their self-perceptions are somehow com- patible with a health-compromising behavior like smoking Khrell and Btioski 1984). Interventions based on the affectke model sought to increase adolescents' Perceptions of self-worth and to establish or clarify a health-related value system that would support a young Person's decision not to smoke. Another assumption typicalIy made by prevention Programs based on the affective education approach was that information specific to tobacco was neither necessary nor sufficient for reducing the onset of ciga- mttesmoking among adolescents (Goodstadt 1978). These affective approaches evolved out of the direct experi- ences of educators and counselors who had begun to associate cigarette smoking among adolescents with vari- ous problem behaviors, including school absenteeism, low achievement motivation, and antiso&l behavior. The intervention programs suggested that adolescents who experienced such problems could rectify them through changes in their attitudes toward school, family, or community, if sufficiently motivated to do so. Reviews based on more than a decade of research have concluded that interventions based on the affective education model were no more,, effective in reducing adolescent smoking than those based on the information deficit model. Some studies have even suggested (that is, without conclusive findings) that these programs may have had the untoward effect of eliciting interest in the behaviors they attempted to discourage (Kinder, rape, Walfish 1980; Schaps et al. 1981; Hansen et al. 1988). Nonetheless, affective education programs marked the begiming of an era during which enormous effort was expended to design smoking-prevention interventions that were more directly related to the factors believed to cause smoking among adolescents. Correlates of Adolescent Smoking Behavior Evaluations of interventions before the mid-1970s suggested that these approaches were insufficient for several reasons. For example, although high school and college students were the intended targets of smoking- prevention programs in the 1940s and 197Os, the devel- opment of smoking behavior follows a series of stages that typically begin earlier in life, when students are in the sixth or seventh grade (Lever&al and Cleary 1980). Such findings suggest that smoking-prevention inter- ventions need to be initiated earlier than high school and that attention should be given to the various stages that adolescent smokers moved through as they developed from nonsmokers into regular smokers (Chassin, I'resson, Sherman 1985). As opposed to the narrow focus of prevention mod- els based solely on information or affective factors, a broader focus and a more diverse set of correlates or antecedents began to emerge as important determinants of adolescent cigarette smoking. As reviewed by Evans (19841, these factors have been studied categorically as so&demographic, environmental, behavioral, and per- sonal variables. Throughout the 198Os, using data from both longitudinal (McAlister, Krosnick, Milbum 1984) and cmss+e&onal (Chassin, presson, Sherman 1984) surveys, researchers developed a clearer understanding of the etiology of smoking behavior. Prezwntion 123 Surgeon General's Report This research showed that prevention strategies in the 1960s and 1970s had greatly underestimated the ex- tent to which adolescent smoking was determined by social environmental variables. An exception was the early work of the proactive physicians group Doctors Ought to Care (DOC), which argued that tobacco adver- tising and promotional activities strongly influence the social environment of adolescents (Blum 1980). A de- tailed overview of the relationships of social environ- mental variables to .the acquisition of smoking behavior is found in Chapter 4 of this report (see "Environmental Factors in the Initiation of Smoking"). As the major risk factors associated with smoking onset were identified, they were translated into new intervention methods, and the programs that resulted were substantially different from the approaches that had preceded them. Instilling Skills for Resisting Social Influences to Smoke Prevention research grants from the National Insti- tute on Drug Abuse @JIDA) and the National Institutes of Health (Bell and Levy 1984; USDHHS 1984; Stone 1985; Glynn 1989) were largely responsible for creating a wave of prevention program development from the late 1970s throughout the 1980s. These efforts fundamen- tally redefined the concept of primary prevention in several ways. First, programs began to make better use of social, psychological, and behavioral theories as a basis for un- derstanding what approaches might work to modify patterns of smoking onset among adolescents. Program design became far more data driven, as researchers be- gan to design intervention components based directly on findings from theory-based etiologic research on adoles- cent smoking. This orientation led to an improved un- derstanding and targeting of the determinants and correlates of smoking behavior among adolescents. Much information was published about the characteristics and components of successful smoking-prevention programs. Much of what has been learned focuses particularly on social infhrences, norms, and skills training and has the objective of attaining behavioral abilities, methods, skills, and techniques (rather than knowledge, beliefs, or moti- vation) that make it easier to adopt and maintain health- enhancing behavior patterns, such as not smoking. Lastly, the research methodology used to evaluate the efficacy of preventive interventions became far more sophisti- cated and considerably more rigorous. Intervention Objectives This prevention intervention approach recog- nizes the social environment as the most important determinant of smoking onset and focuses on the devel- opment of norms and skills to identify and resist social influences to smoke. Underlying this approach is the assumption that adolescents who smoke may lack spe- cific skills to deal successfully with various social influ- ences that support smoking. Such influences include the misperception that most people smoke, the perceived desirable social image of smoking, the appeal of cigarette advertising and promotional activities, and the persua- sive effects of sibling and peer smoking. Although con- siderable variation can be found across curricula, programs that instill the skills needed to resist such social influences have included a fairly consistent group of components that include training in resisting social pres- sures (e.g., marketing) and peer pressures to smoke and training that fosters general assertiveness, decision mak- ing, and communication skills (Botvin and Wills 1985). These programs also promote healthful normative ex- pectations and particularly correct the misperception that most adolescents smoke. Earlier programs for adolescents designed their messages to generate fear and anxiety about long-term disease risk. Approaches that teach skills to guard against social influences have assumed that scare tactics based on long-term health risk are not pertinent to the short- term perspective of many adolescents. The principal messages of skills-based intervention have thus focused on the negative, short-term social consequences of smok- ing, on the techniques of tobacco advertising that may be falsely appealing to adolescents, and on the socially sa- lient advantages of being a nonsmoker. Overall Program Structure In 1987, the NCI convened a panel of experts to establish consensus regarding the essential structural elements of effective smoking-prevention programs (USDHHS 1991). The panel agreed that eight features could be considered both necessary and sufficient for effective school-based smoking-prevention programs (Glynn 1989) (Table 4). In a recent meta-analysis (Mooney 1992) of outcomes of research studies conducted from 1974 through 1989 on school-based smoking prevention, the essential elements of the NCI expert panel were examined and mostly supported. This meta-analysis will be discuss& later in this chapter. Most of the successful programs that provide skills for resisting social influences share several major cur- riculum components. One of these is to convey the short- term negative consequences of cigarette smoking, including social undesirability and physiological impair- ment. Another component is to have students explore inaccurate normative expectations; students thus learn that cigarette smoking is not a normative behavior for 124 Prevention preventing Tobacco Use Among Young People adolescents their age and that the majority of persons in any age group are nonsmokers. Students examine the reasons that adolescents say they smoke, including to be accepted by peers, to appear mature, or to help cope with difficult situations. The factors that affect adolescent smoking can also be explored, including the influence of parents, peers, and mass media; for example, students can learn how role modeling and advertising can falsely establish positive cultural meanings for smoking (see "Research on the Effects of Cigarette Advertising and Promotional Activities on Young People" in Chapter 5). A related component is to engage students in training, modeling, rehearsing, and reinforcing methods that counter these influences and to coach students to com- municate these techniques to others. Some approaches also include generic personal and social skills training to promote overall competence and reduce motivations to smoke (Botvin and Wills 1985). Curriculm Format Among the numerous approaches to teaching skills to resist sociai influences to smoke, the format variations are in most cases minor (Best et al. 1988). For example, a number of these approaches rely on classroom teachers to deliver the smoking-prevention program. The six- session program designed by Colquhoun and Cullen (1981) focused on refusal skills training provided by classroom teachers with the help of local physicians. Biglan, Glasgow, et al. (1987), on the other hand, trained health and science teachers to deliver intervention ses- sions on four consecutive days, followed by a booster session two weeks later. Other intervention variations have used a combina- tion of trained staff or teachers plus student peer leaders. Pa~y,IQepp,andSillas(1989),forscample,usedsame-age pees in a smoking-prevention program that promoted cardiovasda.r health. Ellickson and Bell (19901, on the other hand, employed trained health educators to deliver their intervention to seventh gradexs and contrasted this approach by delivering the intervention through students' mgulartea&rsa&tedbyteenleademSiily,Arkinet al. (1981) organ&d seventh-grade student nominations of classmates who students felt would be effective peer lead- ers Those selected then served as discussion leadem and helped students rehearse and n&play appropriate re- sponsestosituatiomthatsimuIatedsociaI~. In Project SHOUT (Students Helping Others Un- derstand Tobacco), college undergraduate students in psychology, health sciences, and other majors worked for college credit toward their degrees by serving as peer leaders to young adolescents. The college students were mature and reliable enough to deliver interventions (both in the classroom and over the telephone, in booster calls) yet sufficiently youthful to be acceptable to an adult- wary audience (Young et al. 1988; Young et al. 1990; Elder et al. 1993). Table 4. Essential elements of school-based smoking-prevention programs 1. Classroom sessions should be delivered at least five times per year in each of two years in the sixth through eighth grades. 2. The program should emphasize the social factors that influence smoking onset, short-term consequences, and refusal skills. 3. The program should be incorporated into the existing school curricula. 4. The program should be introduced during the transition from elementary school to junior high or middle school (sixth or seventh grades). 5. Students should be involved in the presentation and delivery of the program. 6. Parental involvement should be encouraged. 7. Teachers should be adequately trained. 8. The program should be socially and culturally acceptable to each community. Source: Glynn (1989). Praention 125 Surgeon General's Report Other variations in intervention approaches have used media supplements and involved students' par- ents. Flay et al. (1987), for example, used a five-day smoking-prevention curriculum in junior high school classrooms and coordinated it with five different five- minute video segments aired on a local television station. The focus of these television segments was smoking pre- vention, and they were followed the next week by five more segments dealing- with smoking cessation (Flay et al. 1987). Pentz et al. have trained health, science, and social studies teachers to deliver a social influences program that was reinforced by 10 homework activity sessions involving parents and other family members in role play- ing and other forms of behavioral rehearsal (Penk, Dwyer, et al. 1989). In a related project, this group has developed a component that asks parents to attend organizational meetings, support school activities, and participate in an educational workshop (Penk, MacKinnon, Flay, et al. 1989). The results of these studies are discussed later in this chapter, along with other community programs. Biglan, Glasgow, et al. (1987), have also designed a component that tries to enlist direct parental support of their standard classroom curriculum. The component relies on a set of four mailed messages for parents of participating students. These messages reinforce class- room activities, encourage family discussions of smoking in general, and urge parents to establish family policies regarding smoking. Walter, Vaughan, and Wynder (1989) embedded smoking education in a comprehensive school health education program, the Know Your Body Program, with fourth- through eighth-grade students in New York. This more comprehensive program had a significant impact on multiple risk-related behaviors, including cigarette smoking. Finally, Cain, Dudley, and Wilkerson's (1992) "Tar Wars" program has used health professionals to deliver antitobacco messages with the help of fourth-, fifth-, and sixth-grade children. The students participate in a poster contest to counter the messages of tobacco advertising, and a communitywide media cam- paign complements the school program. Originating in 1977, this program is based on the DOC program Superhealth 2000, which similarly emphasized counteradvertising skills among 7th- through 10th~grade students (Blum 1980). A number of recent reviews have closely examined issues related to program design and content (Botvin and Wills 1985; Flay 1985; Glasgow and McCaull985; Hansen 1992). Rather than replicate these efforts here, the next section will provide examples of the range of programs that can teach adolescents the skills needed to resist social influences to smoke. Exemplary Programs for Resisting Social Influences Social Inoculation In the mid-1970s Evans et al. developed the first prevention program that instilled adolescent skills to resist social influences to smoke. The program, described as "social inoculation," taught students methods for rec- ognizing and coping with pressures to smoke from peers, family, and the media fMcGui.re 1964). The program's hypothesis was that if young adolescents received class- room "inoculations" of "peer pressure," for example, and learned how to deal with it, they would be more prepared to resist actual social pressure from peers. Additional emphasis was placed on the immediate physi- ological impairments that smoking produces, rather than on long-term consequences (Evans et al. 1979). The program used videotapes of nonsmoking peers to im- part information and to teach skills needed to resist social influences. In the pilot study involving 750 seventh- grade students, the proportion of nonsmokers in the experimental group who 10 weeks earlier had reported smoking at least one cigarette was approximately half that of those in the control group. This research group introduced a notable proce- dure for enhancing the validity of self-reported smoking behavior among study subjects. Students were shown a film indicating that their smoking status could be veri- fied biochemically by analyzing a sample of their saliva. The perception that the samples could be examined led to more truthful reporting by students and thereby de- creased misclassification bias due to inaccurate self-re- ports (see "Validity of Measures of Smoking," Appendix 2, in Chapter 3). Although interpretations of results from this early work were complicated by a variety of methodological flaws (Flay 19851, Evans' work provided the foundation for much of the smoking-prevention research that fol- lowed over the next decade. Project CLASP Later in the 197Os, McAlister et al. (1980) developed anintervention&ledCounselingLeadershipAboutSmok- ing Pressure CLASP), during which peer leaders from high school were trained to help junior high school stu- dents develop the skills needed to resist social pressures to smoke. The students learned to identify social pressures and then rehearsed and modeled strategies for coping with them McAlister et al. 1980). Besides this use of older students as peer leaders, the use of behavioral rehearsal methods and strategies to enhance commitment to nonsmoking was an innovation 126 Prevention preventing Tobacco Use Among Young People that has been incorporated into many of the prevention programs developed later. The intervention consisted of three sessions delivered on consecutive days, followed by four booster sessions delivered over the remainder of the seventh-grade school year. Nine months after pre- test, 5.6 percent of the treatment group and 9.9 percent of the control group reported smoking during the previous week-a statistically significant 56 percent difference be tween the groups. These reductions in smoking preva- lence were observed up to the 10th grade. Life Skills Training botvin (1986) has developed another variation of the social influences approach that includes resistance skills, behavioral rehearsal, role playing, self-control, de- cision making, problem solving, and self-reward, as well as components devoted to increasing self-esteem, self- confidence, autonomy, and assertiveness. The program,' called Life Skills Training, includes various aspects of cognitive-behavioral psychological training. The pro- gram consists of 15 to 20 sessions for seventh-grade students; booster sessions are given in the eighth and ninth grades. The specific objectives of the program are to teach skills that help students resist direct pressures to smoke; to enhance students' self-esteem, self-mastery, and self-confidence in order to decrease their susceptibil- ity to indirect social pressures to smoke; to prepare stu- dents to cope with anxiety induced by social situations; to enhance students' knowledge of the actual prevalence of smoking among adolescents and adults; and to pro- mote attitudes and beliefs consistent with nonsmoking. This program has been evaluated extensively in progressively larger studies over the past decade; the encouraging results have ranged from 40 to 80 percent reductions in smoking prevalence, and long-term effects havelasteduptofouryears(BotvinandDusenbury1989). In the most comprehensive evaluation of the Life Skills Training program to date, 56 schools in three different geographic regions were randomly assigned to three study conditions: Life Skills plus one-day teacher train- ing, Life Skills plus video training for teachers, and a control condition. Significant positive effects were re- ported for cigarette use (see Table 5) and for smoking- relatedknowledge,attitudes,andnormativeexpectations. In most cases, the two treatment conditions had similar results; students in both groups demonstrated more posi- tive effects than students in the control group (Botvin et al. 1990). The effects of the Life Skills Training program have been demonstrated when the program hasbeen delivered by project staff, older peers, or regular classroom teachers. These effects have also been demonstrated on inner-city Table 5. Outcomes of the Life Skills Training (LST) program: adjusted third-year follow-up mean for smoking-related knowledge, expectations, personality measures, and behavior Adjusted mean scores* LST LST (with (with Smoking variable teacher training) video training) Knowledge Smoking prevalence 1.10* 1.16+ Smoking consequences 4.W 4.60A Smoking acceptability 1.495 1 .52A Normative expectations Adult smoking 3.92+ 3.95+ Peer smoking 3.80' 3.77+ Personality measures Self-esteem 34.25+ 34.07 Self-efficacy 19.27 19.20 Social anxiety 28.71t 29.36 Smoking behavior 1.46" 1.50$ Source: Botvin et al. (1990). `Means for LST groups differ from control group at + p < .05, fp -C .Ol, _p < .OOl, and "p < .OOOl. Control .93 4.13 1.37 4.22 3.92 33.65 19.26 29.92 1.63 Prevention 127 161-235 95-5 Surgeon General's Report populations of predominantly Hispanic (Botvin et al. 1992) and black (Botvin et al. 1989; Botvin and Cardwell 1992) adolescents. The SODAS Model Several researchers have developed a variation of the social skills training approach that adds to the basic components of resistance skills, behavioral rehearsal, and role playing. The additional components focus on self- control, decision making, problem solving, and self- reward. Using a problem-solving approach called Stop, Options, Decide, Act, and Self-Praise (SODAS), students are taught self-control skills for smoking prevention coupled with self-reward for personal successes (S&i&e et al. 1986; Gilchrist et al. 1986). This research group has conducted a variety of studies evaluating this intervention model in different settings and using varied delivery modalities. The results of these studies have consistently demonstrated that treat- ment students reduce their smoking prevalence more than control students and that treatment students have greater positive changes in smoking-related know- ledge and attitudinal factors (Schinke and Gilchrist 1984, 1985,1986). The Waterloo Smoking-Prevention Program Investigators at the University of Waterloo (Ontario, Canada) have carried out a series of largescale, long& dinal studies evaluating the efficacy of an intervention that teaches sixth-grade students the skills they need to resist social influences to smoke. This intervention is based on an integrative model of attitude and behavior changes surrounding health issues that suggests that if information is attended to, comprehended, and accepted, it may lead to changes in beliefs. Beliefs, however, will not necessarily lead to changes in attitudes, and attitudes will not necessarily lead to changes in intentions unless values, expectancies, and social influences are consid- ered. Lastly, intentions will not necessarily lead to changes in behavior unless the individual has the requisite con- trol and coping skills (Flay 1986). The intervention program has three main compo- nents that are delivered to sixth graders in six one-hour weekly sessions. The first component provides informa- tion on the consequences of smoking and the reasons that adolescents smoke. The second component exam- ines social influences-including family, friends, other peers, and the media-that promote smoking; students then learn specific skills to resist these pressures. In the third component, the students are asked to integrate information learned in all previous sessions in order to make a decision about their future smoking behavior and to publicly commit to nonsmoking, if that is their decision. In the first large-scale randomized trial of this pro gram, 22 schools were randomly assigned to treatment and control conditions. Sixth-grade students in the 11 treatment schools received the curriculum plus booster sessions in seventh and eighth grade. Initial evaluation results indicated that although the intervention did not reduce levels of regular smoking or significantly increase the probability of remaining a nonsmoker, it prevented the onset of experimental smoking through the end of the eighth grade. The results were particularly encouraging for students who were at highest risk of becoming regular smokers because they had tried smoking in grade six or because their parents, siblings,`or friends were smokers (Best et al. 1988). The University of Waterloo research group has reported six-year follow-up data for the same cohort of students studied earlier through the eighth grade. Ninety percent of the students were located for this follow-up study, and data were obtained from over 80 percent of them. These students had not received any additional intervention after the eighth grade. The significant inter- vention effects observed in this cohort after the eighth grade had begun to disappear by the fifth year after the intervention; by the sixth year, there was no longer a significant difference between treatment and control stu- dents (Flay et al. 1989). These results (see Figure 2) suggest that the initial positive impacts of such interven- tions may dissipate over time (Kozlowski et al. 1989), particularly if intervention activities and booster sessions do not extend throughout middle school, junior high, and high school (botvin and Botvin 1992). School-based programs may also be strengthened by supplementary intervention activities that extend beyond the school con- text into the community (Perry, Klepp, Shulk 1988; Perry et al. 1992). The Minnesota Smoking-Prevention Program The Minnesota Heart Health Program is a community-based cardiovascular disease prevention pro- gram that has been carried out in selected Minnesota study communities during the past decade (Blackburn et al. 1984). As a part of this program, the Minnesota Smoking-Prevention Program (MSPP) has addressed the prevention of tobacco use by influencing the social and psychological factors known to promote the onset of smoking. The activities in MSPP are often led by peer (sarne- age) leaders who are trained to communicate the social and psychological messages embodied in the program. The students first form small groups to discuss the short-term, social consequences of smoking. By 128 Prevention prtwrz ting Tobacco Use Among Young People Pxarninirtg actual data and discussing young people's tendency to overestimate smoking prevalence, students lenm that smoking is not a normative behavior in our ++ety. After exploring why adolescentssmoke, students J~SS positive alternatives to smoking. Students then learn how these misperceptions about smoking are estab- lish& in our culture through advertising and role model- ing by peers and adults. Students practice the skills to resist the social influences that promote smoking, in- &ding peer influences and advertising techniques. gear the end of the program, students state a goal to remain nonsmokers In evaluating the effects of the MSPP in eight junior high schools, Murray et al. (1988) reported that after four irears, the peer-led social influences intervention reduced ;he incidence of daily and weekly smoking by 35 to 50 percent. In contrast, no reduction was observed in an adult-led group that was taught the health consequences of smoking or in a comparison group enrolled in an existing curricuhun covering general health topics. These differences, however, were no longer statistically sig- nificant at the five- and six-year follow-ups (Murray et al. 1988). As part of this overall research program, the Class of 1989 Study was established to test the efficacy of the MSPP approach when introduced as part of a broader, community-based health promotion effort (Perry et al. 1992). Researchers hypothesized that the school-based intervention program would have longer-lasting effects if it was introduced in communities where adults were involved in communitywide smoking-cessation pro- grams, where antismoking ordinances in the schools and public community spaces were being considered, and where integrated school and community intervention Figure 2. Six-year follow-up of the first Waterloo School Smoking Prevention Trial: proportion of subjects smoking regularly and experimentally at each wave of the study 45 40 35 O Experimental * Regular - r Control -Program Control Program Control Program Control Program Control Program Control Program Control Program (End of Trial) Wear 1 (Year 2 (Year 3 (Year 4 (Year 5 (Year 6 follow-up) follow-up) follow-up) follow-up) follow-up) follow-up) Study condition Sauce: Flay et al. (1989). Prmention 129 Surgeon General's Report activities were offered. Throughout junior and senior high school, smoking prevalence was significantly lower among students in the intervention community than among students in the control community. The results of this study are discussed later in this chapter, along with other communitywide programs. International Research on Smoking- Prevention Programs Intervention studies reported in the English- language literature outside the United States concentrate primarily on school-based interventions directed at sec- ondary school students (persons aged 11 years or older). In many cases, these intervention programs have adopted some elements of U.S. school programs in order to reflect different local conditions. This section reviews several of the more rigorously evaluated programs and pays par- ticular attention to programs that have been followed up for two or more years after intervention. Western Australia Armstrong et al. (1990) conducted a large random- ized trial evaluating peer- and teacher-led social influ- ence programs among 12- and 13-year-old students in Western Australia. The authors used the MSPP program (Arkin et al. 1981) and resurveyed the students one year and two years after the intervention. Although the ef- fects of the program were not strong, at the two-year follow-up, the smoking prevalence in the control group was 6.6 percent higher than in the teacher-led interven- tion group and 8.1 percent higher than in the peer-led intervention group. North Karelia Youth Project The North Karelia Youth Project in Finland (part of the International Know Your Body study) was a two- year controlled trial that targeted schoolchildren in grade seven (12 and 13 years old) and included components on smoking prevention, physical activity, and reduction of dietary fat and alcohol consumption (Puska et al. 1981, 1982). The smoking intervention program was peer-led and involved three 45-minute sessions for grade seven; these students received seven shorter sessions the fol- lowing year (a schedule similar to that of Project CLASP). The program included sessions on social pressures to smoke, ways to resist such pressures, ways to cope with social anxiety, the short- and long-term health effects of both active and passive smoking, and the impact tobacco growing has on the environment. Health educators from the project team delivered a direct, intensive intervention (intervention A) in two schools (one urban and one rural). A less intensive, countywide intervention (intervention B) provided ma- terials and training to local youth and temperance work- ers. The evaluation involved the two intervention A schools, tie matched intervention B schools selectd from the county, and two matched reference schools selected from another county that did not receive an organized intervention. h&a et al. (1982) found that among boys, the prevalence of occasional smoking (one or two times per month) had increased by 30 percent in the reference group, by 8 percent in the A group, and by 13 percent in the B group. Among girls, the prevalence of occasional smoking had increased by 20 percent in the reference group, by 18 percent in the A group, and by 9 percent in the B group. Vartiainen et al. (1990) reported the results of an eight-year follow-up and found that the prevalence of "any smoking" in the reference group was 10 percent higher than in the A group and 16 percent higher than in the B group. United Kingdom In the United Kingdom, Nutbeam et al. (1993) con- ducted a controlled trial of two school-based interven- tions. The Family Smoking Education Project was derived from a program first developed in Norway (Aam et al. 1983). Directed toward lO- through 12-year-olds, the project consisted of five lessons on the immediate health effects of smoking and on the wider environmental im- pact of tobacco growing and use. A notable feature was a leaflet sent to parents to encourage their support for school-based smoking education. The Smoking and Me project was the United Kingdom adaptation of the MSPP. Directed toward lO- through 12-year-olds, the program consisted of six sessions highlighting a range of social influences and equipping students with skills to manage these social pressures. At the first-year and second-year follow-ups, no differences were observed between the intervention population and the control population for either smoking uptake or personal skills. Overall, school-based smoking education programs that have been evaluated internationally have met with limited success in the past decade. In general, these programs were brief and were not continued through the high school years. Many countries are taking more com- prehensive approaches to smoking control among young people; such approaches include community action, fur- ther restrictions on tobacco advertising and promotion, and substantially higher tobacco tax rates than are found in the United States. 130 Prevention preventing Tobacco Use Among Young People Meta-Analyses of School-Based Smoking . prevention Extensive discussions of the methodological issues inherent in research on smoking prevention have been thoroughly discussed elsewhere (Cook and Campbell 1979; Flay 1985; Biglan, Severson, et al. 1987; Murray and Hannan 1990). The primary issues have included ques- tions of mixed units of analysis, attrition of the subject (student) population, integrity of implementation, and homogeneity of the subject population. These issues have been partly accounted for in four important meta- analytic studies published since 1980. Tobler (1986) examined 143 studies of drug-use prevention programs for 6th- through 12thgrade stu- dents and found that these programs had an overall significant impact on behavior, skills, and knowledge. The study also found that peer-led programs and pro grams dealing with social influences were more effective than other modalities. Tobler (1992) later confirmed these findings with more rigorous analytic methods. The Rundall and Bruvold (1988) meta-analysis of 40 studies of school-based programs to prevent smoking examined knowledge, attitude, and behavioral outcomes of social influence programs versus traditional programs; the so cial influence programs were more likely to affect attitudes and behavior. Rooney (1992) examined 90 school-based tobacco-use prevention programs con- ducted from 1974 through 1989 that sought to develop skills to resist social influences. The meta-analysis took into account the clustering of students in schools and used the school as the unit of analysis. Results mdicated that smoking prevalence was 4.5 percent lower among students in the social influence programs than among students in control conditions. The social influence pro- grams that were most effective at one-year follow-up were those that were delivered to sixth-grade students, that used booster sessions, that concentrated the pro- gram in a short time period, and that used an untrained peer to present the program. Under these more optimal conditions, long-term smoking prevalence was reduced by about 25 percent. Bruvold's meta-analysis (1993) included 94 sepa- rate interventions from the 1970s and 1980s. The inter- vention programs were categorized as rational Qxoviding factual information), developmental (increasing self- esteem and decision-making skills), social-norms- oriented (providing alternatives and reducing alienation), and social-reinforcement-oriented (developing skills to deal with social pressures to smoke). The me&analysis showed that the rational approach had very little impact on smoking behavior, that the developmental and social norms approaches had equivalent and intermediate impact on smoking behavior, and that the social rein- forcement approach had the greatest impact on smoking behavior (Bruvold 1993). Discussion In retrospect, research on smoking prevention has by its very nature had to contend with various threats to validity posed by factors such as mixed units of analysis, differential attrition, and inconsistent implementation. To a large extent, the most recent research studies have been designed to deal with these methodological ob- stacles and have still found moderately strong preven- tion effects (Rooney 1992; Bruvold 1993). Therefore,mast reviews of the smoking-prevention reseamh literature cons& tidy have come to the same conclusions, which can be sum- marized under three general findings. First, a variety of individual msearch reports @c&in and Dusenbury 1989; Flay et al. 1989), severai comprehen- sive literature reviews @lay 1985; Best et al. 19881, and four meta-analyses Crobler 1986; Rundall and Bruvold 1988; Rooney 1992; Bruvold 1993) have all reported lower prevalences of smoking among students in social influence programs than among students in equivalent comparison groups or randomly assigned control groups. The differ- ence between treatment and nontreatment groups ranges from 25 to 60 percent and persists from one to four years, Second, as Best et al. (1988) have underscored, given thenumberofresearchstudies,thevariabilityinprogramfor- mat and scope, the various cofnmunties and cultures in whichthesestudiesw~undertaken,andthepotential~~ to internal and external validity in school-based research, the consistency of overall findings and reductions in smoking prevalence across all these studies is rather remarkable. Third, it has been observed repeatedly that the positive shorter-term intervention effects reported in adolescent smoking-prevention studies tend to dissi- pate over time (Murray et al. 1989; Pen& MacKinnon, Dwyer, et al. 1989; Flay et al. 1989; Ellickson, Bell, McGuigan 1993). This general trend has been particu- larly evident among school-based intervention studies that included little or no emphasis on booster sessions, few (if any) communitywide activities, or few (if any) mass-media-based components (Botvin, Renick, Baker 1983; Perry, Klepp, Shultz 1988; Botvin and Botvin 1992). These interventions may be enhanced if they are em- bedded in a more comprehensive school health educa- tion program (AlIensworth and Kolbe 1987; Walter, Vaughan, Wynder 1989). The comprehensive school health approach needs further evaluation but is promis- ing as an effective prevention tool. Only the social influence approaches have been scientifically demonstrated (through replicated research Prevention 131 Surgeon General's Report studies) to reduce or delay adolescent smoking. Still, the effects of these programs have not been sustained without additional educational interventions or commu- nity components. This experience suggests that pro- grams grounded in school-based skills training are indeed important for preventing smoking, although more sus- tained and comprehensive efforts may be needed for long-term success. The concept of reciprocal determinism (Bandura 1986) would argue that these complementary compo- nents should target the elements of the dynamic person- environment interaction that school-based interventions may not be capable of reaching, much less influencing. These components would include the types of commu- nity, environmental, legislative, policy-based, and soci- etal interventions described later in this chapter. Preventing Smokeless Tobacco Use Introduction The 1986 publication of the Advisory Committee`s Report to the Surgeon General (USDHHS 1986b) on the health consequences of using smokeless tobacco (chew- ing tobacco and snuff) and subsequent reports of wide- spread use of smokeless tobacco among children and adolescents (Boyd et al. 1987; USDHHS 1992b) have called forth a wide range of written and media materials (including films, pamphlets, and video programs) on the risks of using smokeless tobacco (Wilson and Wilson 1987; Laflin, Glover, McKenzie 1987). These materials, made available to school personnel and parents, have aimed at countering the perception that smokeless to- bacco is a safe alternative to cigarettes. Materials have been produced by federal agencies (such as the NC1 and the National Institute of Dental Research), voluntary nonprofit groups (such as the ACS), and professional organizations (such as the American Dental Association and the American Academy of Otolaryngology). These materials have been distributed widely, but the degree of their diffusion has not been evaluated, nor has their effect on young people's use of smokeless tobacco. Evaluation of School-Based Efforts or regular use and to promote or assist cessation for adolescent and young adult users. Nine research grams on smokeless tobacco use have been funded by the NQ since 1987; most are focused on adolescent populations (USDHHS 199Ob), and results are pending. Although most of these projects have been school-based preven- tion activities, some programs have targeted youth in non-school settings (e.g., 4-H clubs, Little League base- bail clubs, and Native American community centers). The prevention programs that have been evaluated have targeted both smoking and smokeless tobacco use among middle and high school students. The primary focus has been on middle school (grades 6-8, ages 12-14). Smokeless tobacco prevention has also been included as part of more comprehensive`curricula to prevent drug use, such as Here's Looking at You,2ooO (Roberts, Fitzmahan & Associates, Inc., and Comprehensive Health Educa- tion Foundation 1986), or as part of community-based interventions to reduce drug use. Seldom have pro- grams to prevent smokeless tobacco use been instituted independent of other substance-use prevention or of a more general tobaccouse prevention effort. Since smoke- less tobacco products are used primarily by males, the overall prevalence of use is lower than that of smoking. There is also less concern about the health effects of smokeless tobacco than about those of illegal drugs and cigarettes. This logical inclusion, however, of smokeless tobacco prevention in the context of other prevention efforts makes the evaluation of the smokeless tobacco component problematic. A factor that more directly obscures the impor- tance of smokeless tobacco prevention is the widespread acceptance of use by both young people and parents. Youth generally perceive that smokeless tobacco use is a safe alternative to cigarette smoking. For example, in one study, 77 percent of school-aged children believed that cigarette smoking was very harmful to one's health, yet only 40 percent believed the same of smokeless tobacco use (Schaefer et al. 1985). Parents are also more likely to accept smokeless tobacco use than smoking among teens (Chassin, Presson, Sherman 1985; see `Tarental Reaction to Smokeless Tobacco Use" in Chapter 4). because the increased use of smokeless tobacco among youth is a relatively recent phenomenon, few pro- grams for preventing adolescent use of these products have been evaluated for either short- or long-term efficacy. Those that have been evaluated have been but one compo- nent of a broad tobacco-prevention program. The Oregon Research Institute Program In several studies, young adolescents have received a preventive curriculum that targeted both smoking and smokeless tobacco use. In one such study (Severson et al. 1991), a social influences program conducted by the Or- egon Research Institute was delivered by regular class- room teachers and by same-age peer leaders to entire classrooms in randomly assigned schools. The brief seven-session program significantly reduced smokeless tobacco use among males in both seventh and (to a lesser In response to the emerging concern about the health risks of regular smokeless tobacco use, the Na- tional Institutes of Health has funded numerous research grants to develop interventions to prevent initiation 132 Prevention Preventing Tobacco Use Among Young People extent) ninth grades. Parallel analysis failed to show that the intervention had any positive effect on cigarette smoking. The results for smokeless tobacco use, how- ever, were particuIarly encouraging, since only two of the seven class periods of the intervention were devoted to smokeless tobacco. The intervention used in the Severson et al. (1991) study sought to make students sensitive to overt and covert pressures to use tobacco and taught effective ways to respond to these pr&sures. The students practiced how to refuse offers of tobacco. Besides using a struc- tured curriculum with role-play activities, the teacher used videotapes to standardize instruction and maintain student interest. The program was taught by regular classroom teachers; same-age peer leaders assisted in role-playing activities for the seventh-grade students. A videotape titled Big Diper (Oregon Research Institute 1986) was developed to highlight the physical and social consequences of smokeless tobacco. To involve parents, brief brochures were mailed to students' homes. Toward No Tobacco Use A study by Sussman et al. (1993) reports positive results in their Toward No Tobacco Use (TNT) project for reducing smokeless tobacco use. The study compared four different prevention curricula developed to coun- teract three types of factors related to the onset of tobacco use that are typically addressed within a comprehensive social-skills program. These include peer approval for using tobacco, incorrect social information provided about tobacco use, and lack of knowledge about physical con- sequences of tobacco use. The development of these curricula is detailed in previous reports (Sussman 1991). Smokeless tobacco use was significantly less preva- lent among students who had received the TNT inter- vention than among those who had not (Sussman et al. 1993). The results of the evaluation of this lo-lesson curriculum intervention suggest that learning about the physical consequences of smokeless tobacco use can be as successful as a social influences program and that a combination of both is probably best for deterring use of smokeless tobacco. The Sussman et al. (1993) study in southern California and the Severson et al (1991) study in Oregon suggest that smokeless tobacco use can be reduced through school-based programs that try to pre vent all types of tobacco use among seventh- and ninth- grade studen& Project SHOUT Elder et al. (1993) developed Project SHOUT, a social influences program that has been evaluated in 22 junior high schools in San Diego County, Califor- nia. Based on an operant conditioning model of tobacco use (Elder and Stem 19861, the intervention was delivered in randomly assigned schools to seventh-grade students. Intervention and assessment continued for three years (through seventh, eighth, and ninth grades). Because of multiple school changes at the end of the eighth grade, Project SHOUT used telephone calls and programnewsletters for the ninth- grade intervention. At the three-year follow-up, the intervention had a significant effect on cigarette use, smokeless tobacco use, and combined cigarette and smokeless tobacco use. The intervention effect was particularly strong during the ninth grade (Elder et al. 19931. The three-year intervention and follow-up is a strength of this study; previous studies have been limited to a single intervention year and one-year follow-up. Programs for Native American Populations Smokeless tobacco use by Native American youth on reservations is higher than that of other groups (Schinke et al. 1989). There is evidence of early, frequent, and heavy use of snuff and chewing tobacco by Native American children and Alaskan Natives (S&i&e et al. 1987X Young people in these populations begin using smokeless to- bacco at an early age, and girls use it at levels almost equal to boys &hinke et al. 1987). Current reservation-based interventions aimed at reducing this pattern of smokeless tobacco use have not yet been evaluated. These ongoing programs are sensitive to the unique aspects of tobacco use by Native Americans, since tobacco has traditionally played a role in sacred rites. The programs make extant materials appropriate for Native American children by creating a specific curriculum for the tribal group and having Native Americans provide the intervention in schools or other settings on their reservation. Smoking Cessation Introduction Few studies have examined adolescent smoking cessation. The four primary sources of information on adolescent cessation are national probability surveys on patterns of adolescent attempts to quit (see "Attempts to Quit Smoking" and "Self-Reported Indicators of Nicotine Addiction Among Smokers" in Chapter 3), con- venience sample surveys of adolescents who have tried to quit on their own, reports from prevention projects on effects of treatment on youth who were smokers at baseline, and programs that explicitly try to recruit adolescent smokers into cessation programs. The rela- tively few intervention studies vary considerably in sci- entific quality; many are anecdotal or descriptive accounts of programs. Prevention 133 Surgeon General's Report Convenience Samples of Adolescents Who Try to Quit Smoking Although national surveys ask a great many re- spondents a few questions about quitting smoking, some smaller studies have more deeply probed the experience. The role of nicotine's pharmacologic effects has received increasing attention, culminating in the 1988 Surgeon General's report on nicotine addiction. The report dem- onstrated that cigarette smoking is characterized by the same addictive processes that have been observed with other drugs that are abused (USDHHS 1988). Recent observations of adolescents who have tried to quit smok- ing suggest that dependency or addiction has developed in many adolescent smokers and may play an important role in their attempts to quit. Data from both Great Britain (McNeill et al. 1986; McNeill1991) and the United States (Hansen 1983; Hansen et al. 1985; Brshler et al. 1989) show that many adolescents who try to quit have withdrawal symptoms that parallel those reported by adult smokers (see "Nicotine Addiction in Adolescence" in Chapter 2). Inasurveyof116Britishschoolgirls(aged 11 through 17) who had tried to quit smoking, 63 percent reported withdrawal effects. The degree of withdrawal effects was related positively to both self-report and biochemical mea- sures of nicotine intake (McNeill et al. 1986). These f%d- ings were replicated, although without biochemical measures, in a study of American 6th through 12th- graders of both sexes (Brshler et al. 1989). Over half of the smokers in both of these studies reported attempts to quit, and most were unsuccessful. These observations, along with other data summarized in Chapters 2, 3, and 4, strongly suggest that adolescent smoking is more than socially driven and that addictive processes in adolescents are similar to those that characterize adult smoking. Effect of Smoking-Prevention Programs on Cessation Smoking-prevention programs have typically, and appropriately, targeted younger adolescents. In these populations, prevalence rates tend to be low, and those who smoke are mostly doing so infrequently. These studies, reviewed earlier in this chapter, focus on pre- venting onset or on preventing the progression from experimentation to regular smoking. The impact of smoking-prevention programs on students who are ex- perimental or regular smokers appears to be small and inconsistent (Best et al. 1984; Johnson et al. 1986; Biglan, Severson, et al. 1987). However, the small number of regular smokers (that is, those who smoke every week) tends to preclude meaningful analyses of cessation re- sulting from these programs (Best et al. 1984). Cessation Interventions in the School Young people who smoke have been a persistent concern of both educators and voluntary health agencies. A number of materials and programs for adolescent smoking cessation have been developed and imple- mented, but evaluation typically has been anecdotal or descriptive (Hulbert 1978; Patterson 1984; Brink et al. 1988). Many of the older programs are described by Thompson (19781, USDHEW (1979), and Seffrin and Bailey (1985). Cessation programs are sometimes led by peers, sometimes by teachers or volunteers. Participants are recruited through school channels such as newslet- ters, classes, and public address announcements. Evi- dence from these descriptive reports, as well as from some of the formal research programs described below, indicates that recruitment is difficult; adolescent smokers are hesitant to come forth. In some instances, the par- ticipants in the school cessation programs are referred by school authorities for infractions of school smoking policies and are thus not coming to these programs voluntarily. These issues are illustrated by a program evalua- tion reported by the American Lung Association (un- published data). The program, developed by a Minnesota affiliate of the American Lung Association, was evalu- ated in 22 schools in four states. A total of 241 students (mean age = 16 years old) participated in eight 5Ominute sessions during school hours over a four-week period. Over half the students, however, were required to par- ticipate as a consequence of being caught smoking on school grounds. This inclusion of nonvoluntary partici- pants may partly explain the program's low success rate: at the end of the sessions, only 30 students (14 percent) reported that they were abstinent (program dropouts were counted as smokers). Low cessation rates like these, coupled with recent legislation such as the Oregon law forcing school authorities to take action against stu- dents caught smoking on school grounds, signal the need for more effective cessation approaches for student smokers. Lotecka and MacWhinney (1983) compared an in- tervention group focusing on cognitive behavioral skills (N = 53) with a group only receiving health information (N = 54). Less than 50 percent of the students in each group participated in the three-month follow-up. Of those assessed at that time, 78 percent of the students in the cognitive behavior group reported a decrease in smok- ing, and only 4 percent reported an increase; the compa- rable figures for the information-only group were 46 percent and 31 percent. No information was provided on complete abstinence. Given that reported rates of smoking are relatively unreliable and that the program 134 Prevention praenting Tobacco Use Among Young People did not report cessation rates, this study cannot be con- sidered conclusive. Perry et al. (1980, 1983) conducted two school- based cessation interventions in California schools. hi the first, IOth-grade classes in three high schools (N = 477) received a special program that focused on im- mediate physiological effects of smoking and on social cues that influence the adoption of smoking. Classes in two control schools (N = 394) received standard infor- mation on long-term health effects. The program con- sisted of four consecutive 45minute sessions in regular health classes conducted in the fall. Posttest outcome data were obtained approximately five months later and included carbon monoxide measures of smoking. At the posttest, the experimental group, compared with the control group, had a significantly greater percentage of subjects who reported abstinence in the previous week (22 vs. 16 percent) and month (30 vs. 24 percent). Parallel significant differences were also found for carbon mon- oxide measures. In their second study, the Perry group (1983) tried to sort out the specific efficacious components within the intervention program by analyzing three kinds of pro- grams-those that discussed long-term health effects (the control group), those that discussed immediate and long- term physiological effects, and those that discussed so- cial consequences--and comparing programs taught by either teachers or college students. Twenty health classes and four high schools were randomized by using a facto- rial design. The study obtained three-month follow-up data that included self-reports and carbon monoxide breath tests. Using entire 10th~grade health classes solved the recruitment problem but yielded a limited number of current smokers; the relatively small number of pretest smokers in this study (N = 82) precluded finding any significant difference between the groups. Overall, 23 percent of the pretest smokers reported not smoking at the three-month follow-up. Teachers tended to be more effective with the traditional curriculum covering long- term health effects, and college students seemed more effective with the social influences curriculum. The largest and most systematic school-based ado lescent cessation study has not yet been published. Bur- ton et al. (unpublished data) worked with rural and suburban high schools in two states. Within each of the 16 treatment schools, students volunteering to partici- pate in a cessation clinic were randomly assigned to a clinic or to a control group of students told they were on a waiting list. Clinic students were further randomly assigned either to a clinic designed to address addiction or to one designed around psychosocial dependency. Clinics consisted of five sessions spaced over one month. A follow-up session was held three months after the fifth session. The control participants were also invited to the follow-up session, where smoking status was assessed both by self-report and measurement of saliva co&-tine. At the three-month follow-up, 8.4 percent of clinic participants and 10.5 percent of controls were abstinent. When corrected for biochemical verification, these figures become 6.8 and 7.9 percent, respectively. There was con- siderable attrition; students lost to follow-up were as- sumed to be smokers. The negative results in the study are especially sobering because the investigators had previ- ously conducted 31 focus groups with adolescents to help inform the intervention's reuuitment strategies and con- tent (Sussman et al. 1991). Difficulty in recruiting adolescent smokers in school programs has been a pervasive problem for investigators. Adolescents may be concerned about parents or teachers learning that they smoke (since parental consent could be required for participation). Adolescents may also be less motivated thanadults to quit, since long-term health con- sequences carry less weight with the young. A simpler explanation of low recruitment is that prevalence rates are low; schools do not provide large populations of smokers from which to recruit. Multisite trials that pool subjects may be needed before rigorous and meaningful evalua- tions can take place. Cessation Interventions Based Outside the School Hollis et al. (in press) tried an unusual approach to recruit young smokers. Adolescents between 14 and 17 years of age who were members of a large health mainte- nance organization (HMO) were mailed a screening ques- tionnaire that asked about "health habits." Those who reported that they had smoked in the past week were asked if they would participate in a twoyear study of adolescent health and were randomly assigned to either an intervention group that received help to quit smoking or a control group that received no such help. The focus of the intervention was an office visit with a nurse practitioner at a conveniently located HMO clinic. Incentives were offered for attending these ses- sions, each of which lasted about 60 minutes. The partici- pants reviewed their health history, watched and discussed a video on adolescent smoking cessation, were encouraged to set a quit date, and were given tips and strategies for successful quitting. Those who wanted to quit smoking received a follow-up call one week later; additional calls were also made, depending on the adolescent's continued interest in quitting. Participants who had quit smoking were eligible to participate in a lottery with chances to win $100. All participants were followed up at one year, at which time both self-report and biochemical (saliva cotinine, carbon monoxide) data were obtained. The Proven tion 135 Surgeon General's Report intervention and control groups had similar self-report measures of smoking (i.e., measured in number of ciga- rettes in the last month, week, day) and similar biochemi- cal indicators of smoking. No relationship was found between the number of contacts with the HMO interven- tionist and either quitting rates or the number of ciga- rettes smoked. Similar interventions in health care settings with adult smokers have usually yielded positive results (e.g., Hohis et al. 1991), but this was clearly not the case for adolescent smokers. Discussion The data reviewed indicate consistently that ado- lescent smokers frequently try to quit but are usually unsuccessful, often have withdrawal reactions much like adult smokers, are difficult to recruit and retain in formal cessation programs, and are not responsive to programs thus far developed. Further basic research and new. directions for intervention are clearly needed. Data pre sented in Chapter 3 (see "Adult Implications of Adoles- cent Smoking") from the Monitoring the Future Project show that well over 80 percent of adolescents who smoked half a pack a day or more as seniors in high school (over 15 percent of the sample) were smoking five to six years later as young adults; over half of these were smoking a pack or more a day at follow-up. In the absence of intervention, adolescent smokers will most likely be come adult smokers. Smokeless Tobacco Cessation Introduction Of the estimated six million people who regularly use smokeless tobacco, half are under age 21 (USDHHS 1986b). Data from several national surveys show an increase in the prevalence of smokeless tobacco use, spe- cifically in the use of moist snuff among young males (Boyd and Glover 1989; Marcus et al. 1989; Novotny et al. 1989; Rouse 1989; see "Current Use of Smokeless To- bacco" in Chapter 3). The high prevalence of smokeless tobacco use underscores the growing need to help young people quit. To date, there are few published studies of smoke- less tobacco cessation. The withdrawal symptoms for smokeless tobacco are the same as those for smoking- cravings for the substance, irritability, distractibility, and hunger (Hats&an&Gust, Keenan 1987)-althoughthese symptoms may be less intense and felt less frequently. Because of these similarities, most cessation programs for smokeless tobacco users are multicomponent treatments that use key elements from smoking-cessation programs that have been extensively evaluated in largescale studies (Sever-son 1993). Clinical Studies Clinical studies of smokeless tobacco cessation have been done with both adolescents and adults. The first published study of smokeless tobacco cessation was re ported by Glover (1986), who adapted the ACS' Fresh Start Adult Smoking Cessation Program for use with 41 adults who used smokeless tobacco. This pilot study resulted in a six-month self-reported abstinence rate of only 2 percent. However, these subjects had not vohm- tarily sought assistance in quitting; they had been re- quired to attend the program for violating school rules at a college that prohibited the use of tobacco products. Low success rates are not surprising in a nonvoluntary cessation program. Eakin, Severson, and Glasgow (1989) reported an intervention with adolescent male daily users, aged 14 through 18, who were recruited from high schools in Eugene, Oregon. The study recruited 25 students, five of whom also smoked cigarettes concurrently. The program consisted of three small group meetings with counselors, each lasting approximately one hour, during which the focus was on developing coping skills for cessation. Of the 21 subjects who completed treatment, two s&j&s had quit using smokeless tobacco by the end of treatment, and three subjects were abstinent at the six-month follow-up. Compared with the other students, however, these suc- cessful quitters had consumed a smaller amount of smoke lesstobaccoatbaselineandwerelessaddicted,asmeasured by an adapted Fagerstriim Tolerance Questionnaire (Fagerstrom 1978). They were also more involved in school athletics than those who did not succeed at quitting. School-Based Efforts Three recent studies of smokeless tobacco cessation are informative about school-based cessation and self-help approaches. Burton et aL (unpublished data) report msulk from a school-based cessation clinic model tested in 16 high schools in Illinois and California. Within each school, ciga- rette and smokeless tobacco users were recruited and either randomly (and vohmtarily) assigned to a cessation clinic or told the clinics were filled. Clinics consisted of five sessions over a one-month period. A sixth session was held three months later to assess the intervention and control groups. The attrition rate for the clinic group was higlx almost half the students did not complete the treatment. Of the 16 smokeless tobacco users who completed five sessions, seven reported quitting at the end of the treatment; none of the five students in the control group reported quitting. However, when the clinic dropouts were included as the denominator and the results corrected for biochemi- cal verification, the quit rate for students in the smoke- less tobacco clinic was 15 percent; none of the control 136 Prevention Proven ting Tobacco Use Among Young People subjects had quit at the three-month follow-up. The study suggests that a school-based multisession clinic can achieve small cessation rates for adolescent subjects who volunteer, although the volunteer rates for the study were notably low. Persons going through treatment for smokeless tobacco addiction often request an oral substitute to help them through withdrawal. Smokeless tobacco users re port using cinnamon sticks, gum, sunflower seeds, finely ground mint leaves, or other chewed foodstuffs to lessen the effects of withdrawal (Severson 1992). To evaluate the use of nonnicotine substitutes as aids for smokeless tobacco cessation, a recent study compared the use of a ground-up mint product, chewing gum, and no substi- tute (Chakravorty 1992). Subjects were recruited from six high schools in rural Illinois. Two schools each were randomly assigned to either the treatment group (mint snuff substitute), gum group, or lecture-only control group. Within schools, smokeless tobacco users were invited to volunteer for a two-session school-based ces- sation program. Eighty-three males were recruited to participate. Of the 70 students who completed the treat- ment, 30 were in the mint group, 15 in the gum group, and 25 in the lecture-0 nly group. At the end of the treatment period, all three groups had about the same quit rates. Eleven students reported quitting smokeless tobacco, but nine of these quitters also smoked cigarettes. The author reports that students using the mint snuff substitute significantly reduced their frequency and in- tensity of smokeless tobacco use, but the study had rio biochemical verification of use. The results suggest that adolescent males who use smokeless tobatico can be recruited to attend sessions at school and that nontobacco oral substitutes may be a helpful adjunct to quitting. Research with adults suggests that health care pro- viders can motivate some adult users of smokeless to- bacco to quit (Stevens et al., in press). The clinical opportunity to provide advice on quitting in the context of health care delivery has been referred to as a. "teach- able moment" (vogt et al. 1989; Morosco 1986). The results are modest in terms of overall quit rates, but having dentists, hygienists, nurses, and physicians coun- se1 their patients to quit using smokeless tobacco could have a significant effect on prevalence. The Stevens et al. (in press) study provided the first examination of a large- scale, low-cost intervention to encourage smokeless to- bacco users to quit. This program, which was conducted in the context of regular hygiene visits, provided strong evidence of the effect of smokeless tobacco use on oral health: 73 percent of the adult users in this study had identifiable oral lesions (Little, Stevens, La Chance, et al. 1992). Parallel studies with youth or studies of programs using physicians or other health care providers have not been conducted. Smokeless Tobacco and Cigarettes Young people who use smokeless tobacco may also smoke cigarettes. Studies have reported that from 12 to 30 percent of all regular users of smokeless tobacco also use cigarettes (E&in, Severson, Glasgow 1989; Wil- liams 1992; Stevens et al., in press; see "Use of Smokeless Tobacco and Cigarettes" in Chapter 3). This relationship is critical, since cessation programs may motivate smoke less tobacco users to quit using snuff or chewing tobacco, yet not affect their use of cigarettes-and thus not affect their addiction to nicotine. Moreover, deprivation of one substance may lead to a direct increase in the use of the other (Biglan, La Chance, Benowitz, unpublished data). Cessation rates among men who use both tobacco prod- ucts are significantly lower than those among men who use smokeless tobacco exclusively (Stevens et al., in press). Research and Programmatic Challenges Certain peculiar aspects of smokeless tobacco use may present problems to those who plan or study cessa- tion programs. The lack of public data on the nicotine content of smok&ss tobacco products is not only a research problem but a challenge to cessation efforts that might reduce the severity of nicotine withdrawal by gradually cutting back on nicotine ingestion. Such ef- forts are further hampered, as are studies or programs depending on self-monitoring of product consumption, by the nonuniform (bulk) packaging of most smokeless products and by the variation in the amount of product that constitutes a "pinch" (of chewing tobacco) or a "dip" (of moist snuff) (Severson et al. 1990.) External monitoring of use also has inherent limitations, since snuff (and to a lesser extent, chewing tobacco) can be used surreptitiously. On the other hand, the oral lesions frequently experienced by smokeless tobacco users readily indicate smokeless use--and provide direct physi- cal evidence to the user that this behavior has detrimen- tal health effects (Little, Stevens, Severson, et al. 1992). The relations