Moderators of outcomes in a fully-automated web-based brief motivational alcohol intervention for adolescents

Abstract
Aims: We explored moderators of effectiveness of WISEteens (Web-based brief Intervention for SubstancE using teens), a fully automated web-based brief motivational intervention targeting risky substance use among adolescents. Based on previous studies we examined differential effects on drinking with gender, readiness to change, self-efficacy, drinking severityalcohol risk status and parental monitoring as hypothesized moderators. Methods: We analysed completers data from a two-armed RCT study with follow-up assessment after three months, including N= 211 self-enrolled adolescents (16-18 years) who screened positive for at-risk substance use in Sweden, Belgium, Czech Republic and Germany. The trial compared a single session brief motivational intervention to an assessment-only control group with an adapted AUDIT-C scores for past month drinking frequency, quantity, and frequency of binge drinking as study outcome. Results: The analyses revealed a statistically significant moderation effect for gender on past month total drinking index score, with a stronger effect for males. In contrast, readiness to change, self-efficacy, alcohol risk statusdrinking severity and parental monitoring did not moderate the effects. Conclusions: Although the trial was limited by large drop out, our findings imply that web-based interventions can be particularly effective for male adolescents but the effects of WISEteens were largely independent of other individual characteristics. Web-based brief intervention should integrate gender specific components to raise effectiveness for females.