***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Theory-driven , mass media interventions prevent smoking among youth . This study examined effects of a media campaign on  adolescent smoking cessation .  Four matched pairs of media markets in four states were r and omized to receive or not receive a 3-year television/radio campaign aim ed at adolescent smoking cessation based on social cognitive theory . The authors enrolled 2,030 adolescent smokers into the cohort ( n = 987 experimental ; n = 1,043 comparison ) and assessed them via annual telephone surveys for 3 years . Although the condition by time interaction was not significant , the proportion of adolescents smoking in the past month was significantly lower in the experimental than comparison condition at 3-year follow-up when adjusted for baseline smoking status . The media campaign did not impact targeted mediating variables . A media campaign based on social cognitive constructs produced a modest overall effect on smoking prevalence among adolescents , but the role of theory-based constructs is unclear Abstract Objective : To evaluate the effectiveness of an antismoking campaign conducted by the Health Education Board for Scotl and . Design : Descriptive survey of adult callers to a telephone helpline ( Smokeline ) for stopping smoking ; panel study of a r and om sample of adult callers ; assessment of changes in prevalence of smoking in Scotl and before and after introduction of the helpline Setting : Telephone helpline . Subjects : Callers to Smokeline over the initial one year period . Detailed information was collected on a 10 % sample ( n=8547 ) . A cohort of adult smokers who called Smokeline ( total n=848 ) was followed up by telephone interview three weeks , six months , and one year after the initial call . Main outcome measures : Numbers of adult smokers calling helpline ; changes in smoking behaviour , especially stopping smoking among cohort members ; and changes in prevalence of smoking in the general population . Results : An estimated 82 782 regular adult smokers made genuine contact with Smokeline over the year , representing about 5.9 % of all adult smokers in Scotl and . At one year 143 of the cohort of 848 callers ( 23.6 % ; 95 % confidence interval 20.2 % to 27.0 % ) reported that they had stopped smoking , and 534 ( 88.0 % ; 85.4 % to 90.6 % ) reported having made some change . About 19 500 ( 16 700 to 22 350 ) adult smokers , equivalent to 1.4 % ( 1.2 % to 1.6 % ) of the mean adult smoking population , stopped smoking with direct help from Smokeline . During the second year of the campaign ( 1994 ) smoking prevalence among 25 - 65 year olds in Scotl and was 6 % ( 2.0 % to 10.0 % ) lower than it had been before the start of the campaign . Conclusion : The Health Education Board for Scotl and 's antismoking campaign reached a high number of adult smokers , was associated with a highly acceptable quit rate among adults given direct help through Smokeline , and contributed considerably to an accelerated decline in smoking prevalence in Scotl and . Key messages There was an unprecedented response to the antismoking campaign of the Health Education Board for Scotl and , with an estimated 5.9 % of adult smokers in Scotl and responding to the invitation to call Smokeline , a free telephone helpline , in its first year of operation A panel study of callers to Smokeline , with telephone interviewing , obtained an acceptable response rate of 71.6 % at one year follow up Nearly a quarter ( 23.6 % ) of smokers who called the helpline were not smoking at the one year follow up , a success rate that exceeds a proposed st and ard for comparable health education and promotion interventions The Smokeline campaign contributed considerably to an accelerated ( 6 % ) reduction in smoking among people aged 25 - 65 in Scotl and during 1992 - 4 The study findings provide further evidence of the efficacy of mass media antismoking initiatives with a social support The purpose of this study was to compare longitudinal smoking prevention program effects estimated on a population -based cohort sample of sixth- and seventh- grade students ( average n per year = 4,664 ) using different schools as units of analysis ( middle/junior high school as the school of origin or high school as the endpoint school of intervention ) . Fifty schools in 15 school districts were demographically matched and assigned to either a school and community-based program for prevention of cigarette , alcohol , and marijuana use , or a health education as usual control group .  Smoking was measured by question naires administered to the students . An expired air ( CO ) measure of smoking was also administered to increase accuracy of self-reports . Program effects were estimated with regression analyses , controlling for school-level socioeconomic status , racial/ethnic make-up , urbanicity , and grade . Using school of origin as the unit of analysis , program effects showed 1 year net reductions of -8 , -6 , and -5 % in prevalence rates of smoking in the last month , last week , and last 24 hr ; 2-year program effects showed similar net reductions of -6 , -5 , and -3 % ( P 's less than 0.10 - 0.001 ) . Analyses with endpoint school as the unit showed slightly weaker effects at the 2-year follow-up , the year during which 64 % of students had moved to a junior high or high school . The findings are discussed in terms of the potential contamination of experimental groups in longitudinal studies from school consolidations , family mobility , and feeder patterns to high schools , and the different smoking environments represented by middle , junior high , and high schools A major issue in smoking prevention research is that no study has tried to equate program success expectancies across experimental and placebo control conditions . Equivalent overall program success expectancies should be established to help rule out the effects of extra-theoretical variables which influence program outcomes . The present study tested whether an attention-placebo ( information based ) smoking prevention program would produce equivalent expectancies about the likelihood of program success in comparison to an experimental social influences program . To try to equate program success expectancies , the design of the two programs differed in content but was similar in procedure . Fourteen middle schools were r and omly assigned to the two conditions . As hypothesized , baseline expectancies were found to predict outcome measures , even after controlling for baseline smoking intentions , ethnic group , and gender . Second , the equivalence of program expectancies at posttest was tested . Youths held equivalent overall expectancies for success across conditions . This study suggested the need to control for program expectancies in prevention research , and showed that program expectancies could be controlled for by equating process of program delivery The effectiveness of a smoking cessation campaign that included both printed and televised material s was evaluated in registrant and r and omly acquired sample s of smokers during the first month postcampaign and again at 3 months . Registrant and r and om sample s differed on several sociodemographic variables .  Registrants had much higher rates of abstinence at both times compared to the r and omly acquired group .  Nicotine gum replacement  was used more frequently among the registrant group . Fifteen percent of registrants who had not attempted to quit at Time 1 were abstinent 3 months postcampaign . Registering to participate in print and televised cessation programs may be related to a change in smoking behavior This paper reports a controlled evaluation of the six-part BBC TV series " So You Want To Stop Smoking ? " which aim ed to give advice and encouragement to smokers who wanted to stop . In an experimental design , 134 cigarette smokers in two firms were shown either the first two programs in the series or a control film of the same length .  Smokers in the former group were asked to watch the remaining four programs at home on their own television sets . Question naires were sent to participants four months and one year later , and cl aims of abstinence were vali date d biochemically . The results did not provide clear evidence that the BBC series was more effective in encouraging smokers to try to stop and helping them to succeed than the control film . For comparison with our own results , we also abstract some findings from an uncontrolled but larger-scale evaluation conducted by the BBC 's research department RATIONALE Although involuntary exposure to maternal smoking during the in utero period and to secondh and smoke are associated with occurrence of childhood asthma , few studies have investigated the role of active cigarette smoking on asthma onset during adolescence . OBJECTIVES To determine whether regular smoking is associated with the new onset of asthma during adolescence . METHODS We conducted a prospect i ve cohort study among 2,609 children with no lifetime history of asthma or wheezing who were recruited from fourth- and seventh- grade classrooms and followed annually in schools in 12 southern California communities .  Regular smoking was defined as smoking at least seven cigarettes per day on average over the week before and 300 cigarettes in the year before each annual interview . Incident asthma was defined using new cases of physician-diagnosed asthma . MEASUREMENTS AND MAIN RESULTS Regular smoking was associated with increased risk of new-onset asthma .  Children who reported smoking 300 or more cigarettes per year had a relative risk ( RR ) of 3.9 ( 95 % confidence interval [ 95 % CI ] , 1.7 - 8.5 ) for new-onset asthma compared with nonsmokers . The increased risk from regular smoking was greater in nonallergic than in allergic children . Regular smokers who were exposed to maternal smoking during gestation had the largest risk from active smoking ( RR , 8.8 ; 95 % CI , 3.2 - 24.0 ) . CONCLUSIONS Regular smoking increased risk for asthma among adolescents , especially for nonallergic adolescents and those exposed to maternal smoking during the in utero period BACKGROUND This paper presents the student outcomes of a large-scale , social-influences-based , school and media-based tobacco use prevention and cessation project in Southern California . METHODS The study provided an experimental comparison of classroom delivery with television delivery and the combination of the two in a 2 x 2 plus 1 design . Schools were r and omly assigned to conditions . Control groups included " treatment as usual " and an " attention control " with the same outcome expectancies as the treatment conditions . Students were surveyed twice in grade 7 and once in each of grade s 8 and 9 . The interventions occurred during grade 7 . RESULTS We observed significant effects on mediating variables such as knowledge and prevalence estimates , and coping effort . The knowledge and prevalence estimates effects decayed partially but remained significant up to a 2-year follow-up . The coping effort effect did not persist at follow-ups . There were significant main effects of both classroom training and TV programming on knowledge and prevalence estimates and significant interactions of classroom and TV programming on knowledge ( negative ) , disapproval of parental smoking , and coping effort . There were no consistent program effects on refusal/self-efficacy , smoking intentions , or behavior . CONCLUSIONS Previous reports demonstrated successful development and pilot testing of program components and measures and high acceptance of the program by students and parents . The lack of behavioral effects may have been the result of imperfect program implementation or low base rates of intentions and behavior Objective : To evaluate the effect of an anti-smoking advertisement on young women ’s perceptions of smoking in movies and their intention to smoke . Subjects/ setting : 2038 females aged 12–17 years attending cinemas in New South Wales , Australia . Design /intervention : Quasi-experimental study of patrons , who were surveyed after having viewed a movie at their local cinema . The control group was surveyed during week 1 and the intervention group , during week 2 . Before seeing the movie in week 2 , a 30 second anti-smoking advertisement was shown , which featured a well known female actor drawing attention to the prevalence of smoking in movies . Outcomes : Attitude of current smokers and non-smokers to smoking in the movies ; intention of current smokers and non-smokers to be smoking in 12 months time . Results : Among non-smokers , 48.2 % of the intervention subjects thought that the smoking in the movie they viewed was “ not OK ” compared with 28.3 % of the control subjects ( p < 0.0001 ) . However , there was no difference among smokers in the intervention ( 26.4 % ) and control ( 16.9 % ) groups ( p = 0.28 ) . A higher percentage of current smokers in the intervention group indicated they were unlikely to smoke in 12 months time ( 47.8 % ) than smokers in the control condition ( 31.9 % ) ( p = 0.03 ) . For non-smokers , there was no difference in smoking intentions between conditions , with 95 % saying they would be unlikely to be smoking in 12 months time . Conclusions : This “ real world ” study suggests that placing an anti-smoking advertisement before movies containing smoking scenes can help to “ immunise ” young women against the influences of film stars smoking The Media Ready Program was design ed as a middle school , media literacy education , preventive intervention program to improve adolescents '  media literacy skills and reduce their intention to use alcohol or tobacco products . In a short-term efficacy trial , schools in North Carolina were r and omly assigned to conditions ( Media Ready : n = 214 ; control : n = 198 ) . Boys in the Media Ready group reported significantly less intention to use alcohol in the future than did boys in the control group . Also , students in the Media Ready group who had used tobacco in the past reported significantly less intention to use tobacco in the future than did students in the control group who had previously used tobacco . Multilevel multiple mediation analyses suggest that the set of logical analysis Message Interpretation Processing variables mediated the program 's effect on students ' intentions to use alcohol or tobacco in the future BACKGROUND The 1985 Minnesota Legislature established guidelines for school- 
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However , some of the campaigns which did not detect an effect also exhibited these characteristics .
Effective campaigns tended to last longer ( minimum 3 years ) and were more intense ( more contact time ) for both school-based lessons ( minimum eight lessons per grade ) and media spots ( minimum four weeks ' duration across multiple media channels with between 167 and 350 TV and radio spots ) .
Implementation of combined school-based components ( e.g. school posters ) and the use of repetitive media messages delivered by multiple channels ( e.g. newspapers , radio , television ) appeared to contribute to successful campaigns .