Effectiveness of the 'Healthy School and Drugs' prevention programme on adolescents' substance use: A randomized clustered trial

Abstract

Aim: To evaluate the effectiveness of the Healthy School and Drugs programme on alcohol, tobacco and marijuana use among Dutch early adolescents. Design: Randomized clustered trial with two intervention conditions (i.e. e-learning and integral). Setting: General population of 11-15-year-old adolescents in the Netherlands. Participants: A total of 3784 students of 23 Dutch secondary schools. Measurements: Structured digital questionnaires were administered pre-intervention and at 32 months follow-up. The primary outcome measures were new incidences of alcohol (life-time and 1-month prevalence), tobacco (life-time and 1-month prevalence) and marijuana use (life-time prevalence). Findings: Main effect analyses showed no programme effects on incidences of alcohol consumption (life-time prevalence: e-learning condition: B=0.102, P=0.549; integral condition: B=-0.157, P=0.351; 1-month prevalence: e-learning condition: B=0.191, P=0.288; integral condition: B=-0.140, P=0.445), tobacco consumption (life-time prevalence: e-learning condition: B=0.164, P=0.444; integral condition: B=0.160, P=0.119; 1-month prevalence: e-learning condition: B=0.088, P=0.746; integral condition: B=0.261, P=0.093), or marijuana consumption (life-time prevalence: e-learning condition: B=0.070, P=0.732; integral condition: B=0.186, P=0.214). Conclusion: The non-significant impact of the Healthy School and Drugs programme (a Dutch school-based prevention programme for early adolescents) on incidences of alcohol, tobacco and marijuana use indicates that the programme is either ineffective or implemented inadequately.