Cigarette advertising and teen smoking initiation. A longitudinal study of exposure to retail cigarette advertising and smoking initiation. Longitudinal effects of pro-tobacco and anti-tobacco messages on adolescent smoking susceptibility. Comparing the effects of entertainment media and tobacco marketing on youth smoking. Tobacco industry promotion of cigarettes and adolescent smoking. Comparing the effects of entertainment media and tobacco marketing on youth smoking in Germany. Tobacco marketing and adolescent smoking: more support for a causal inference. Impact of cigarette advertising on smoking behaviour in Spanish adolescents as measured using recognition of billboard advertising. Receptivity to tobacco advertising and promotions among young adolescents as a predictor of established smoking in young adulthood. How do psychological factors influence adolescent smoking progression? The evidence for indirect effects through tobacco advertising receptivity. Effect of cigarette promotions on smoking uptake among adolescents. Predictors of susceptibility to smoking and ever smoking: a longitudinal study in a triethnic sample of adolescents. Influence of education and advertising on the uptake of smoking by children. The influence of three mass media campaigns on variables related to adolescent cigarette smoking: results of a field experiment. Provocative appeals in anti-smoking mass media campaigns targeting adolescents--the accumulated effect of multiple exposures. Exposure to brand-specific cigarette advertising in magazines and its impact on youth smoking. Using the internet to assist smoking prevention and cessation in schools: a randomized, controlled trial. [Smoking initiation in students: cross-sectional and longitudinal study of predictive factors]. Effectiveness of the "Smoke-Free Class Competition" in delaying the onset of smoking in adolescence.
To test the specificity of the association between cigarette advertising and adolescent smoking initiation.
                A longitudinal survey of 2102 adolescents, aged 10 to 17 years at baseline, who never smoked was conducted by using masked images of 6 cigarette advertisements and 8 other commercial products with all brand information digitally removed. The exposure variable was a combination of contact frequency and cued recall of brands for cigarette and other advertisements. Multilevel mixed-effects Poisson regressions were used to assess smoking initiation 9 months after the baseline assessment as a function of cigarette-advertisement exposure, other advertisement exposure, and baseline covariates.
                Thirteen percent (n = 277) of students initiated smoking during the observation period. Although the incidence of trying smoking was associated with increased exposure to cigarette advertisements (10% in the low, 12% in the medium, and 19% in the high cigarette-advertisement exposure tertile initiated smoking), exposure to other advertisements did not predict smoking initiation. Compared with low exposure to cigarette advertisements, high exposure remained a significant predictor of adolescent smoking initiation after controlling for baseline covariates (adjusted relative risk: 1.46 [95% confidence interval: 1.08-1.97]; P < .05).
                Our results support the notion of a content-related effect of cigarette advertisements and underlines the specificity of the relationship between tobacco marketing and teen smoking; exposure to cigarette advertisements, but not other advertisements, is associated with smoking initiation. Accumulating evidence suggests that widespread advertising for cigarettes at the point of sale encourages adolescents to smoke; however, no longitudinal study of exposure to retail tobacco advertising and smoking behavior has been reported.
                A school-based survey included 1681 adolescents (aged 11-14 years) who had never smoked. One measure of exposure assessed the frequency of visiting types of stores that contain the most cigarette advertising. A more detailed measure combined data about visiting stores near school with observations of cigarette advertisements and pack displays in those stores. Follow-up surveys 12 and 30 months after baseline (retention rate: 81%) documented the transition from never to ever smoking, even just a puff.
                After 12 months, 18% of adolescents initiated smoking, but the incidence was 29% among students who visited convenience, liquor, or small grocery stores at least twice per week and 9% among those who reported the lowest visit frequency (less than twice per month). Adjusting for multiple risk factors, the odds of initiation remained significantly higher (odds ratio: 1.64 [95% confidence interval: 1.06-2.55]) for adolescents who reported moderate visit frequency (0.5-1.9 visits per week), and the odds of initiation more than doubled for those who visited > or = 2 times per week (odds ratio: 2.58 [95% confidence interval: 1.68-3.97]). Similar associations were observed for the more detailed exposure measure and persisted at 30 months.
                Exposure to retail cigarette advertising is a risk factor for smoking initiation. Policies and parenting practices that limit adolescents' exposure to retail cigarette advertising could improve smoking prevention efforts. We examined the longitudinal impact of self-reported exposure to pro- and anti-tobacco media on adolescents' susceptibility to smoking, using in-school surveys from a culturally diverse sample. Ethnicity and acculturation also were examined as potential moderators. Middle-school students (N = 2,292) completed self-report questionnaires during the 6th, 7th, and 8th grades. Chi-square analyses were conducted to determine whether reported exposure to pro- and anti-tobacco media varied according to ethnicity, acculturation, and immigration status. Logistic regression models were used to examine whether pro- and anti-tobacco media exposure in 6th grade was associated with susceptibility to smoking by later grades. Recall of people smoking in television programs and pro-tobacco advertisements in stores was associated with adolescent smoking susceptibility. Exposure to anti-tobacco advertisements on television protected against susceptibility. No significant interaction effects between pro- and anti-tobacco media exposure on smoking susceptibility were found. Ethnicity and acculturation did not moderate these associations. Our longitudinal study provides evidence that pro-tobacco media and advertising increases susceptibility to smoking over time. More important, anti-tobacco advertisements are not sufficient to reduce the harmful effects of adolescent exposure to pro-tobacco media. Policy-level interventions such as restrictions in tobacco advertising may be necessary to prevent adolescent smoking. To examine the concurrent effects of exposure to movie smoking and tobacco marketing receptivity on adolescent smoking onset and progression.
                Cross-sectional study of 4524 northern New England adolescents aged 10-14 in 1999 with longitudinal follow-up of 2603 baseline never-smokers. Cross-sectional outcomes included ever tried smoking and higher level of lifetime smoking among 784 experimenters. The longitudinal outcome was onset of smoking among baseline never-smokers two years later. Movie smoking exposure was modelled as four population quartiles, tobacco marketing receptivity included two levels-having a favourite tobacco advert and wanting/owning tobacco promotional items. All analyses controlled for sociodemographics, other social influences, personality characteristics of the adolescent and parenting style.
                In the full cross-sectional sample, 17.5% had tried smoking; both exposure to movie smoking and receptivity to tobacco marketing were associated with having tried smoking. Among experimental smokers, the majority (64%) were receptive to tobacco marketing, which had a multivariate association with higher level of lifetime smoking (movie smoking did not). In the longitudinal study 9.5% of baseline never-smokers tried smoking at follow-up. Fewer never-smokers (18.5%) were receptive to tobacco marketing. Movie smoking had a multivariate association with trying smoking (receptivity to tobacco marketing did not).
                The results suggest separate roles for entertainment media and tobacco marketing on adolescent smoking. Both exposures deserve equal emphasis from a policy standpoint. Whether tobacco advertising and promotion increases the likelihood that youths will begin smoking has important public policy implications.
                To evaluate the association between receptivity to tobacco advertising and promotional activities and progress in the smoking uptake process, defined sequentially as never smokers who would not consider experimenting with smoking, never smokers who would consider experimenting, experimenters (smoked at least once but fewer than 100 cigarettes), or established smokers (smoked at least 100 cigarettes).
                Prospective cohort study with a 3-year follow-up through November 1996.
                A total of 1752 adolescent never smokers who were not susceptible to smoking when first interviewed in 1993 in a population-based random-digit dial telephone survey in California were reinterviewed in 1996.
                Becoming susceptible to smoking or experimenting by 1996.
                More than half the sample (n=979) named a favorite cigarette advertisement in 1993 and Joe Camel advertisements were the most popular. Less than 5% (n=92) at baseline possessed a promotional item but a further 10%(n=172) were willing to use an item. While having a favorite advertisement in 1993 predicted which adolescents would progress by 1996 (odds ratio [OR] = 1.82; 95% confidence interval [CI], 1.04-3.20), possession or willingness to use a promotional item was even more strongly associated with future progression (OR=2.89; 95% CI, 1.47-5.68). From these data, we estimate that 34% of all experimentation in California between 1993 and 1996 can be attributed to tobacco promotional activities. Nationally, this would be over 700000 adolescents each year.
                These findings provide the first longitudinal evidence to our knowledge that tobacco promotional activities are causally related to the onset of smoking. To examine differential effects of smoking in films and tobacco advertising on adolescent smoking. We hypothesize that movie smoking will have greater effects on smoking initiation, whereas tobacco advertising receptivity will primarily affect experimentation.
                Longitudinal observational study of adolescents.
                School-based surveys conducted in Schleswig-Holstein, Germany.
                A total of 4384 adolescents age 11-15 years at baseline and re-surveyed 1 year later; ever smoking prevalence was 38% at time 1.
                The main outcome variable combined two items assessing life-time and current smoking (alpha = 0.87). Baseline never smokers were analyzed separately from those who had tried smoking (ever smokers). Exposure to smoking in 398 internationally distributed US movies was modeled as a continuous variable, with 0 corresponding to the 5th percentile and 1 to the 95th percentile of exposure. Tobacco marketing receptivity consisted of naming a brand for a favorite tobacco advertisement. Ordinal logistic regressions controlled for socio-demographics, other social influences, personality characteristics of the adolescent and parenting style.
                Whereas 34% of ever smokers were receptive to tobacco marketing at time 1, only 6% of never smokers were. Among time 1 never smokers, exposure to movie smoking was a significantly stronger predictor of higher time 2 smoking level [adjusted proportional odds ratio = 2.76, 95% confidence interval (1.84, 4.15)] than was tobacco marketing receptivity (1.53 [1.07, 2.20]). Among time 1 ever smokers, both tobacco marketing receptivity and exposure to movie smoking predicted higher levels of time 2 smoking [2.17 (1.78, 2.63) and 1.62 (1.18, 2.23), respectively], and the two estimates were not significantly different.
                In this longitudinal study, exposure to movie smoking was a stronger predictor of smoking initiation than tobacco marketing receptivity, which was more common among ever smokers. The results suggest that entertainment media smoking should be emphasized in programs aimed at preventing onset, and both exposures should be emphasized in programs aimed at experimental smokers. This prospective study examined the effect of tobacco marketing on progression to established smoking.
                Massachusetts adolescents (n = 529) who at baseline had smoked no more than 1 cigarette were reinterviewed by telephone in 1997. Analyses examined the effect of receptivity to tobacco marketing at baseline on progression to established smoking, controlling for significant covariates.
                Adolescents who, at baseline, owned a tobacco promotional item and named a brand whose advertisements attracted their attention were more than twice as likely to become established smokers (odds ratio = 2.70) than adolescents who did neither.
                Participation in tobacco marketing often precedes, and is likely to facilitate, progression to established smoking. Hence, restrictions on tobacco marketing and promotion could reduce addiction to tobacco. Cross-sectional studies provide empirical support for associations between advertising and adolescent smoking. The aim of this study was to investigate the relationship between Spanish adolescent smoking behaviour and prior awareness of cigarette advertisements on billboards, using a prospective design.
                3,664 Spanish children aged 13 and 14 years filled in self-completion questionnaires at baseline, and 6, 12, and 18 months later (cohort study). Slides of three advertisements were projected at baseline. A multivariate logistic regression analysis was carried out to detect possible association between number of identified tobacco advertisements brands at baseline and smoking status along time, controlling ASE Model smoking determinants, smoking prevention interventions, age, gender and socio-economic status.
                The more advertisements identified at baseline, the greater was the risk of being a smoker (p<0.0001). Final percentages of smokers were 15.8%, 16.3%, 19.3%, and 32.6%, respectively, for zero, one, two and three advertisements recognized. When confounders were controlled, the probability of being a smoker increased with the number of advertisements identified [OR 1.26 (95% CI: 1.09-1.46) after 6 months, OR 1.18 (95% CI: 1.03-1.35) after 12 months and 1.15 (95% CI: 1.02-1.30)] after 18 months. It is possible the association would have been even greater if there had not been a differential loss of smokers from the sample.
                Increased awareness of cigarette advertising was associated with a higher smoking incidence and an increased risk of Spanish children becoming smokers. It is, therefore, imperative that cigarette advertising should be banned as a matter of urgency. We investigated whether receptivity to tobacco advertising and promotions during young adolescence predicts young adult smoking 6 years later.
                Two longitudinal cohorts of adolescents drawn from the 1993 and 1996 versions of the California Tobacco Surveys were followed 3 and 6 years later. At baseline, adolescents were aged 12 to 15 years and were not established smokers. The outcome measure was established smoking at final follow-up. Receptivity to cigarette advertising and promotions was included in a multivariate logistic regression analysis along with demographic and other variables.
                The rate of established smoking at follow-up was significantly greater among members of the 1993 through 1999 cohort (21.0%) than among members of the 1996 through 2002 cohort (15.6%). However, in both cohorts, having a favorite cigarette advertisement and owning or being willing to use a tobacco promotional item showed nearly identical adjusted odds of future adult smoking (1.46 and 1.84, respectively).
                Despite the success of tobacco control efforts in reducing youth smoking, tobacco marketing remains a potent influence on whether young adolescents become established smokers in young adulthood (18-21 years of age). To determine whether novelty seeking and depressive symptoms had mediated or indirect effects on adolescent smoking progression through tobacco advertising receptivity.
                More than 1000 adolescents were monitored from 9th grade to 12th grade and completed annual surveys that measured demographic characteristics, smoking behavior, tobacco advertising receptivity, novelty-seeking personality, depressive symptoms, family and peer smoking, alcohol use, and marijuana use.
                Latent growth modeling indicated that novelty seeking had a significant indirect effect on smoking progression through baseline tobacco advertising receptivity. For each 1-SD increase in novelty seeking, the odds of being more receptive to tobacco advertising increased by 12% (ie, being in a specific category or higher), which in turn resulted in an 11% increase in the odds of smoking progression from 9th grade to 12th grade. The indirect effect from depressive symptoms to smoking progression did not reach significance.
                These findings may inform future research on other factors that influence tobacco advertising receptivity, as well as programs aimed at preventing adolescent smoking initiation and progression. The purpose of this study was to evaluate the association between receptivity to cigarette promotions and smoking uptake in a cohort of adolescents.
                This was a prospective cohort study of 480 4th- to 11th-grade students conducted in three rural Vermont K-12 schools. Cigarette use was determined by self-report at baseline, 12 months (survey 2), and 21 months (survey 3). Proportional odds models were used to evaluate smoking uptake as a function of baseline measures of cigarette use, receptivity to cigarette promotions, and confounding factors, including grade, parental education, peer smoking, and family smoking. Adolescents were receptive to cigarette promotions if they owned or were willing to use a personal item bearing a cigarette brand logo [cigarette promotional item (CPI)]. Smoking status was measured using a 6-point ordinal index that combined experience and attitudes: 0 = never smoker/not susceptible to smoking, 1 = never smoker/susceptible to smoking, 2 = puffer (1 cigarette or less in lifetime), 3 = non-current experimenter (2-99 cigarettes in lifetime/none in past 30 days), 4 = current experimenter, and 5 = smoker (> or =100 cigarettes in lifetime).
                The 480 students were equally distributed across grade at baseline. Environmental exposure to smoking was high, and 30% were receptive to cigarette promotions at baseline. Higher levels on the smoking index at baseline were associated with higher grade in school, peer smoking, and receptivity to cigarette promotions. One hundred eighty-five students (38.5%) had moved to a higher category on the smoking index by survey 3, of whom 30 had become smokers. Receptivity to cigarette promotions at baseline was significantly associated with higher smoking uptake, with 48.7% of receptive students moving up one or more categories on the smoking index [adjusted proportional odds 1.9 (95% CI 1.3, 2.9)]. Acquisition of receptivity to cigarette promotions was also associated with increased smoking uptake, with those becoming receptive in surveys 2 or 3 having significantly higher odds of progression [3.6 (1.8, 7.0) and 2.9 (1.5, 5.5), respectively] compared with those who did not change. Conversely, those who were receptive at one point but became non-receptive in surveys 2 or 3 had lower odds of progression [0.4 (0.2, 0.9) and 0.5 (0.3, 1.1), respectively].
                This study supports a close linkage between tobacco promotional activities and uptake of smoking among adolescents beyond baseline descriptions of receptivity to cigarette promotions. Over time, the likelihood of smoking uptake is increased when an adolescent acquires a CPI or becomes willing to use one and is decreased when an adolescent who owns a CPI loses it or becomes unwilling to use it. This provides strong evidence that elimination of cigarette promotional campaigns could reduce adolescent smoking.
                Copyright 2000 American Health Foundation and Academic Press. This report describes a longitudinal study of the natural course of smoking initiation in a school-based, ethnically diverse (42% White, 37% African American, 20% Hispanic) sample of adolescents in grades 5, 8, and 12 who were followed prospectively for 1 year. A cohort of 659 students was identified who were never smokers at baseline and who completed questionnaires both at baseline and at 1-year follow-up. From this cohort, predictor variables were used to identify ethnic-specific risk factors for (a) "susceptibility to smoking" among the 509 students who were nonsusceptible, never smokers at baseline and (b) "ever smoking" among all 659 students who were never smokers at baseline (both susceptible and nonsusceptible). Logistic regression analyses revealed that parental and household influences (parental education, marital status, household smoking) were important predictors of ever smoking, but not of susceptibility to smoking, for African Americans. Hispanic adolescents were significantly influenced by environmental influences, namely smoking by other household members (ever smoking) and by peers (susceptibility and ever smoking), although peer pro-tobacco influences (friends who smoke or friends' approval of smoking) were important predictors of susceptibility to smoking or ever smoking for all three ethnic groups. Exposure to tobacco-related advertising was a risk factor for White (susceptibility and ever smoking) and African American (susceptibility only) adolescents but not for Hispanic adolescents. Inclusion of the susceptibility to smoking variable in the model predicting ever smoking substantially reduced the importance of other predictors in the model, suggesting that susceptibility to smoking was not an independent risk factor for ever smoking but rather a potential mediating variable. The results of this study offer important insights for designing ethnic-specific strategies for preventing smoking during adolescence. How effective are peer-led programmes in preventing the uptake of smoking by children? In 1981, we conducted a randomized controlled trial of a school-based educational programme for the prevention of smoking in children who were in their seventh year at school. In this article, the reported results of two years of follow-up confirm an earlier report that both teacher-led and peer-led programmes resulted in a reduction, to about the same degree, in the uptake of smoking by girls, while only the teacher-led programme appeared to be effective in boys. In girls, both the teacher-led and peer-led programmes maintained their effects over the two years of follow-up with adjusted differences in prevalence rates of the uptake of smoking relative to the control group of -6.6% (95% CL, -17.3%, 4.0%) and -8.1% (95% CL, -18.9%, 2.7%), respectively, after two years. In boys, the effect of the teacher-led programme was reduced substantially by the second year with a difference in the prevalence rate of -2.8% (95% CL, -11.2%, 5.6%); for the peer-led programme the difference in the prevalence rate was +6.4% (95% CL, -3.6%, 16.4%). Other variables which had a significant effect on the smoking behaviour were the perceived response to cigarette advertising, parental and sibling smoking status, the perceived parental sanctions on smoking behaviour, selected peer influences and the intention to smoke. The children's perceived responses to cigarette advertising showed the strongest and most consistent evidence of an effect on the uptake of smoking by children who initially were non-smokers. After adjustment for the effects of other variables there was an excess of 15.0% (95% CL, 2.1%, 27.9%) in the prevalence rate of smoking after two years for girls who thought that they were influenced by advertising compared with those who did not. The corresponding difference for boys was 15.3% (95% CL, 4.0%, 26.6%). As smoking-prevention programmes only may delay the onset of smoking in children, it is important that legislative measures be introduced to reduce the effects of cigarette advertising. This paper reports findings from a field experiment that evaluated mass media campaigns designed to prevent cigarette smoking by adolescents.
                The campaigns featured radio and television messages on expected consequences of smoking and a component to stimulate personal encouragement of peers not to smoke. Six Standard Metropolitan Statistical Areas in the Southeast United States received campaigns and four served as controls. Adolescents and mothers provided pretest and posttest data in their homes.
                The radio campaign had a modest influence on the expected consequences of smoking and friend approval of smoking, the more expensive campaigns involving television were not more effective than those with radio alone, the peer-involvement component was not effective, and any potential smoking effects could not be detected. This paper reports findings from a longitudinal study that evaluated the accumulated effect of three consecutive mass media campaigns using provocative and dissonance arousing appeals to prevent cigarette smoking by adolescents. In the spring of 1992, all eligible adolescents aged 14 and 15 in one intervention county (N = 4898) and one control county (N = 5439) in Norway were included in the study, and were followed until they were 17 and 18 years of age in 1995. Only students who completed questionnaires both in 1992 and 1995 were included in the analyses. Among the non-smokers at baseline, a significantly lower proportion of adolescents of both genders had started to smoke in the intervention county compared to the proportion in the control county. Among those who were smokers at baseline, significantly more girls in the intervention county had stopped smoking than in the control county, while no significant difference between the counties was detected among boys. Our findings suggest that provocative and dissonance arousing appeals that create affective reactions and lead to interpersonal communication should be given more attention in campaigns designed to influence adolescent smoking. However, such appeals may easily produce negative reactions and the normative context should be thoroughly considered when using such appeals in future interventions. Despite the potential influence of cigarette advertising on youth smoking, few studies have characterized brand-specific magazine advertising exposure among youths or examined its impact on youth smoking behavior.
                A longitudinal youth survey was conducted to assess baseline exposure to brand-specific cigarette advertising in magazines and to measure subsequent smoking behavior. The sample comprised 1,069 Massachusetts youths, ages 12-15 years at baseline in 1993, and 627 of these youths who were interviewed after 4 years.
                Five brands accounted for 81.8% of the gross impressions for magazine advertising among Massachusetts youths. These same brands accounted for 88.4% of the brand market share among 12- to 15-year-old smokers nationally in 1993. The levels of brand-specific advertising exposure in the sample were highly correlated with these national brand market shares (r = 0.96, P = 0. 0002). Among the cohort, baseline brand-specific exposure to cigarette advertising in magazines was highly correlated with brand of initiation among new smokers (r = 0.93, P = 0.0001), brand smoked by current smokers (r = 0.86, P = 0.0004), and brand whose advertisements attracted attention the most (r = 0.87, P = 0.0002).
                By documenting a relationship between brand-specific magazine advertising exposure and brand of smoking initiation among new smokers, this study provides strong new evidence that cigarette advertising influences youth smoking.
                Copyright 1999 American Health Foundation and Academic Press. To evaluate the impact of a classroom-based, Web-assisted tobacco intervention addressing smoking prevention and cessation with adolescents.
                A two-group randomized control trial with 1,402 male and female students in grades 9 through 11 from 14 secondary schools in Toronto, Canada. Participants were randomly assigned to a tailored Web-assisted tobacco intervention or an interactive control condition task conducted during a single classroom session with e-mail follow-up. The cornerstone of the intervention was a five-stage interactive Web site called the Smoking Zine (http://www.smokingzine.org) integrated into a program that included a paper-based journal, a small group form of motivational interviewing, and tailored e-mails.
                Resistance to smoking, behavioral intentions to smoke, and cigarette use were assessed at baseline, postintervention, and three- and six-month follow-up. Multilevel logistic growth modeling was used to assess the effect of the intervention on change over time.
                The integrated Smoking Zine program helped smokers significantly reduce the likelihood of having high intentions to smoke and increased their likelihood of high resistance to continued cigarette use at 6 months. The intervention also significantly reduced the likelihood of heavy cigarette use adoption by nonsmokers during the study period.
                The Smoking Zine intervention provided cessation motivation for smokers most resistant to quitting at baseline and prevented nonsmoking adolescents from becoming heavy smokers at 6 months. By providing an accessible and attractive method of engaging young people in smoking prevention and cessation, this interactive and integrated program provides a novel vehicle for school- and population-level health promotion. This study examines the evolution of tobacco use among schoolchildren in sixth and seventh grades in Barcelona (11-13 years) and identifies smoking risk factors through cross-sectional and follow-up analysis. POBLATION AND METHODS: The cohort consists of 1,003 students attending 13 schools who served as control units for a study assessing the effects of a school-based addictive substances prevention program. Participants answered the same questionnaire in 1990 and 1991. Risk factors for the experimentation and for regular smoking are studied through cross-sectional and prospective studies.
                In a year, smokers increase from 9.7% to 18.9% and regular smokers rise from 1.1% to 5.5%. The initial cross-sectional analysis finds stronger associations than the follow-up one. Some variables loose their significance in the longitudinal analysis. Among non-smokers, the strongest predictors to emerge are intention to smoke, the belief that smoking is fun, peers, siblings and mother consumption, and being male; however girls appear to consolidate the consumption more than boys among the cohort of triers.
                Tobacco use prevalences are consistent with other studies developed in our city. Social environment emerges as an important predictor; friends, siblings and mothers tobacco use and gender are the main risk factors. This paper examines the effectiveness of the "Smoke-Free Class Competition" in delaying the onset of smoking in adolescence. Each participating class must decide if they want to be a "smoke-free class" for the 6-month period from fall to spring. Classes monitor their (non-)smoking behavior and report it to the teacher regularly. Classes in which pupils refrain from smoking for this period of time participate in a prize draw, in which they can win a number of attractive prizes.
                To evaluate the effectiveness of the competition, a sample of 131 participating and nonparticipating classes (number of pupils 2,142; mean age 12.9 years, SD = 0.98) was compared with regard to their smoking behavior. Smoking status was determined by self-assessment on three occasions: (a) prior to the beginning of the competition, (b) 1 month after the competition, and (c) 1 year after the start of the competition.
                From pretest to posttest smoking increased by 7.5% in the comparison group, while it decreased by 0.2% in the intervention group (OR = 2.19; P < 0.001). In the follow-up measurement, a clear increase in smoking prevalence occurs in all groups; however, the pupils in the intervention condition still have a significant lower increase of smoking (OR = 1.45; P < 0.01). Moreover, with regard to the nonsmokers at baseline, pupils in the comparison group showed significantly higher prevalences in smoking than the intervention group in the postmeasurement, 7.8 versus 13.9% (OR = 1.98; P < 0.001), as well as in the in the follow-up-measurement, 17 versus 21.3% (OR = 1.36; P < 0.05).
                The results suggest that the participation in the competition could delay the onset of smoking in adolescence.
Longitudinal studies consistently suggest that exposure to tobacco advertising and promotion is associated with the likelihood that adolescents will start to smoke. Based on the strength and specificity of this association, evidence of a dose-response relationship, the consistency of findings across numerous observational studies, temporality of exposure and smoking behaviours observed, as well as the theoretical plausibility regarding the impact of advertising, we conclude that tobacco advertising and promotion increases the likelihood that adolescents will start to smoke.