Abstract
Introduction: The main objective of this study was to test the longer-term and differential efficacy of a mobile phone‒based life-skills training program designed to prevent substance use among adolescents.
Study design: A 2-arm, parallel-group, cluster RCT with assessments at baseline and follow-up after 6 and 18 months was conducted. The efficacy of the intervention was compared with that of an assessment-only control condition.
Setting/participants: A total of 1,473 students with a mean age of 15.4 years were recruited in 2019/2020 within 89 Swiss secondary and upper secondary school classes.
Intervention: The automated intervention program included online feedback and individually tailored text messages provided over 22 weeks. The contents were based on social cognitive theory and addressed self-management, social, and substance use resistance skills.
Main outcome measures: Primary outcomes included 30-day prevalence rates for problem drinking and tobacco use.
Results: The 18-month follow-up assessments were completed by 1,232 study (83.6%) participants. Those in the intervention group reported lower tobacco-smoking prevalence than the controls (OR=0.67; 95% CI=0.47, 0.96), but no significant difference in problem drinking (OR=0.84; 95% CI=0.61, 1.17) was observed. Among secondary outcomes, the intervention was effective at reducing cannabis-smoking prevalence (OR=0.55; 95% CI=0.39, 0.76) and cannabis use days (Cohen's d= -0.19; 95% CI= -0.29, -0.09), whereas no effects were observed for quantity of alcohol use, quantity of cigarettes smoked, well-being, or social skills. No significant moderators of the primary outcomes were observed.
Conclusions: An automated mobile phone‒based life-skills training program produced longer-term effectiveness in preventing tobacco smoking and cannabis use, whereas no effects were observed for problem drinking. These results suggest that digitally delivered life-skills training programs are similarly effective and are an easy-to-implement alternative to training conducted within a school curriculum.
Paz Castro, Raquel