Effect of a peer‐led prevention program (P2P) on smoking in vocational high school students: Results from a two‐school‐year cluster‐randomized trial

Aims The aim of this work was to measure the impact of P2P (i.e. peer‐to‐peer), a peer‐led smoking prevention intervention, on daily smoking prevalence of adolescents over 2 school years. Design A cluster‐randomized controlled trial was performed over a 16‐month follow‐up (trial status: closed to follow‐up). P2P was implemented 1–3 and 13–15 months after baseline. Assessments took place at baseline and 4, 10 and 16 months after baseline. The research team, assessors and adolescents were blinded to the study‐arm assignment only at baseline. Setting Fifteen vocational high schools in France were randomized into two clusters, using a 1:1 allocation ratio per French department (n intervention = 7, n control = 8). Participants Participants comprised a sample of 2010 students in year 11 (i.e. 15–16 years) in vocational high schools. A total of 437 students could not be assessed at baseline (absent or left school), yielding a total sample of 1573 students (n intervention = 749, n control = 824). Intervention and comparator The P2P programme trained voluntary students to become peer educators and design smoking prevention actions for their schoolmates in the intervention group (n = 945 students), compared with a passive control group (n = 1065 students). Measurements The primary outcome was change from baseline in the prevalence of self‐reported daily smoking (i.e. at least one cigarette per day) at 16 months. Findings The ‘time × group’ interaction indicated that, compared with the control group, the intervention group had statistically significantly fewer daily smokers after 16 months [odds ratio (OR) = 0.33, 95% confidence interval (CI) = 0.20, 0.53]. Similarly, compared with the control group, the intervention group had statistically significantly fewer daily smokers after 4 months (OR = 0.50, 95% CI = 0.30, 0.82) and 10 months (OR = 0.60, 95% CI = 0.37, 0.98). No adverse events of P2P2 were reported. Conclusions A cluster‐randomized trial found evidence that the peer‐led P2P (peer‐to‐peer) smoking prevention intervention reduced the uptake of daily smoking among high school students in France over 16 months.