Reducing smoking in adolescents: cost-effectiveness results from the cluster randomized ASSIST (A Stop Smoking In Schools Trial).

INTRODUCTION: School-based smoking prevention programmes can be effective, but evidence on cost-effectiveness is lacking. We conducted a cost-effectiveness analysis of a school-based "peer-led" intervention. METHODS: We evaluated the ASSIST (A Stop Smoking In Schools Trial) programme in a cluster randomized controlled trial. The ASSIST programme trained students to act as peer supporters during informal interactions to encourage their peers not to smoke. Fifty-nine secondary schools in England and Wales were randomized to receive the ASSIST programme or usual smoking education. Ten thousand seven hundred and thirty students aged 12-13 years attended participating schools. Previous work has demonstrated that the ASSIST programme achieved a 2.1% (95% CI = 0%-4.2%) reduction in smoking prevalence. We evaluated the public sector cost, prevalence of weekly smoking, and cost per additional student not smoking at 24 months. RESULTS: The ASSIST programme cost of £32 (95% CI = £29.70-£33.80) per student. The incremental cost per student not smoking at 2 years was £1,500 (95% CI = £669-£9,947). Students in intervention schools were less likely to believe that they would be a smoker at age 16 years (odds ratio [OR] = 0.80; 95% CI = 0.66-0.96). CONCLUSIONS: A peer-led intervention reduced smoking among adolescents at a modest cost. The intervention is cost-effective under realistic assumptions regarding the extent to which reductions in adolescent smoking lead to lower smoking prevalence and/or earlier smoking cessation in adulthood. The annual cost of extending the intervention to Year 8 students in all U.K. schools would be in the region of £38 million and could result in 20,400 fewer adolescent smokers.

Socioeconomic patterning in changes in child exposure to secondhand smoke after implementation of smoke-free legislation in Wales.

INTRODUCTION: Secondhand smoke (SHS) exposure is higher among children from lower socioeconomic status (SES) households. Legislation banning smoking in public places has been linked with reduced SHS exposure in children. However, socioeconomic patterning in responses to legislation has been little explored. METHODS: A total of 3,083 children aged 10-11 years, within 75 Welsh primary schools, completed questionnaires either before legislation or 1 year later. Saliva samples were provided by 2,787 of these children for cotinine assay. Regression analyses assessed socioeconomic differences in SHS exposure, and associations of legislation with exposure among children from low, medium, and high SES households. Changes in parental smoking in the home, car-based exposure, and perceived norms were assessed. RESULTS: SHS exposure was highest among children from lower SES households. The likelihood of providing a sample containing an undetectable level of cotinine increased significantly after legislation among children from high [relative risk ratio (RRR) = 1.44, 95% CI = 1.04-2.00] and medium SES households (RRR = 1.66, 95% CI = 1.20-2.30), while exposure among children from lower SES households remained unchanged. Parental smoking in the home, car-based SHS exposure, and perceived smoking prevalence were highest among children from low SES households. Parental smoking in the home and children's estimates of adult smoking prevalence declined only among children from higher SES households. CONCLUSIONS: Post-legislation reductions in SHS exposure were limited to children from higher SES households. Children from lower SES households continue to have high levels of exposure, particularly in homes and cars, and to perceive that smoking is the norm among adults.

Changes in child exposure to secondhand smoke after implementation of smoke-free legislation in Wales: a repeated cross-sectional study.

BACKGROUND: Smoke-free legislation was introduced in Wales in April 2007. In response to concerns regarding potential displacement of smoking into the home following legislation, this study assessed changes in secondhand smoke (SHS) exposure amongst non-smoking children. METHODS: Approximately 1,750 year 6 (aged 10-11) children from 75 Welsh primary schools were included in cross-sectional surveys immediately pre-legislation and one year later. Participants completed self-report questionnaires and provided saliva samples for cotinine assay. Regression analyses assessed the impact of legislation on children's SHS exposure at the population level, and amongst subgroups defined by parental figures who smoke within the home. RESULTS: Geometric mean salivary cotinine concentrations were 0.17 ng/ml (95% CI 0.15,0.20) pre-legislation and 0.15 ng/ml (95% CI 0.13,0.17), post-legislation, although this change was not statistically significant. Significant movement was however observed from the middle (0.10-0.50 ng/ml) to lower tertile, though not from the higher end (>0.51 ng/ml) to the middle. Reported exposure to SHS was greatest within the home. Home-based exposure did not change significantly post-legislation. Reported exposure in cafés or restaurants, buses and trains, and indoor leisure facilities fell significantly. The proportion of children reporting that parent figures smoked in the home declined (P = 0.03), with children with no parent figures who smoke in the home significantly more likely to provide saliva with cotinine concentrations of <0.10 ng/ml post-legislation. Amongst children with no parent figures who smoke in the home, the likelihood of 'not knowing' or 'never' being in a place where people were smoking increased post-legislation. CONCLUSION: Smoke-free legislation in Wales did not increase SHS exposure in homes of children aged 10-11. Reported SHS exposure in public places fell significantly. The home remained the main source of children's SHS exposure. The legislation was associated with an unexpected reduction in cotinine levels among children with lower SHS exposure pre-legislation. The findings indicate positive rather than harmful effects of legislation on children's SHS exposure, but highlight the need for further action to protect those children most exposed to SHS.

The relative importance of different measures of peer smoking on adolescent smoking behavior: cross-sectional and longitudinal analyses of a large British cohort.

PURPOSE: To examine the relative importance of smoking behavior of best friends, boyfriends/girlfriends, the wider friendship group, and school year group smoking prevalence as correlates and predictors of smoking behavior (peer influence). The article also aims to assess the relative extent to which smoking behavior is associated with changes in smoking among peers who are selected to be friends (selective association). METHODS: Using two waves of data collected from 4,145 year 8 (12-13 years) and year 9 (13-14 years) students in 29 schools, logistic regression models estimated the cross-sectional association between four year 8 peer influence variables and weekly and occasional smoking, and the extent to which these peer influence variables and three selective association variables were predictors of weekly smoking in year 9. RESULTS: The smoking behavior of best friend, boyfriend/girlfriend, the wider friendship group, and school year group prevalence were cross-sectionally associated with higher odds of weekly and occasional smoking. In longitudinal multivariate influence models, only the smoking behavior of boyfriend/girlfriend and the wider friendship group were associated with weekly smoking. Weekly smoking was associated with maintaining or changing to having smokers among best friends, boyfriends/girlfriends, and the wider friendship group. In models including all variables, only selective association effects were observed. CONCLUSIONS: Although univariate analyses indicate an association of friends', peer group, and year group smoking with current and subsequent smoking behavior, multivariate longitudinal analyses indicate that simple peer influence models do not completely explain adolescent smoking and that a more complex interrelationship exists between smoking, peer's smoking and peer socialization.