The effectiveness of a school-based substance abuse prevention program: EU-Dap cluster randomised controlled trial.

Objective: To evaluate the effectiveness of the school-based drug abuse prevention program developed in the EU-Dap study (EUropean Drug Abuse Prevention trial) in preventing the use of tobacco, alcohol and drugs at the post-test.

Methods: Cluster Randomised Controlled Trial. Seven European countries participated in the study; 170 schools (7079 pupils 12-14 years of age) were randomly assigned to one of three experimental conditions or to a control condition during the school year 2004/2005. A pre-test survey assessing past and current substance use was conducted before the implementation of the program. The program consisted in 12-hour class-based curriculum based on a comprehensive social-influence approach. A post-test survey was carried out in all participating schools, 3 months after the end of the program. The association between program condition and change in substance use at post-test was expressed as adjusted Prevalence Odds Ratio (POR), estimated by multilevel regression model.

Results: Program effects were found for daily cigarette smoking (POR=0.70; 0.52-0.94) and episodes of drunkenness in the past 30 days (POR=0.72; 0.58-0.90 for at least one episode, POR=0.69; 0.48-0.99 for three or more episodes), while effects on Cannabis use in the past 30 days were of marginal statistical significance (POR=0.77; 0.60-1.00). The curriculum was successful in preventing baseline non-smokers or sporadic smokers from moving onto daily smoking, but it was not effective in helping baseline daily smokers to reduce or stop smoking.

Conclusion: School curricula based on a comprehensive social-influence model may delay progression to daily smoking and episodes of drunkenness.