RESUMEN
PURPOSE: A previous trial found lower alcohol use risk during follow-up among adolescent primary care patients receiving computer-facilitated Screening and provider Brief Advice (cSBA) compared to treatment-as-usual (TAU). We tested whether the effect was mediated by alcohol-related perceived risk of harm (PRoH). METHODS: We analyzed data from the cSBA trial on 12- to 18-year-old patients at 9 New England practices (n = 2,096, 58% females). The trial used a quasi-experimental pre-post design with practices being their own controls (TAU followed by cSBA). Because prior alcohol experience could modify effects, we stratified analyses by baseline past 12-month drinking. Among baseline nondrinkers, we tested baseline to 3-month trajectories in PRoH of "trying alcohol" as an effect mediator for drinking at 3- and 12-month follow-up. Similarly, among those with prior drinking, we examined baseline to 3-month trajectories in PRoH of "weekly binge drinking" as an effect mediator for drinking and binge drinking. We used the Hayes product of coefficients mediation approach. RESULTS: Among baseline nondrinkers (n = 1,449), cSBA had higher PRoH compared to TAU for "trying alcohol," and higher PRoH in turn was associated with lower follow-up drinking risk. PRoH mediated their cSBA effect at 12 months, but not 3 months. Among adolescents with prior drinking (n = 647), cSBA had higher PRoH for "weekly binge drinking," which was associated with lower drinking risk at both follow-ups, and lower binge drinking risk at 3 months. PRoH mediated their cSBA effect on drinking at both follow-ups, and binge drinking at 3 months. CONCLUSION: A computer-facilitated primary care intervention enhanced adolescents' perceived alcohol risks which in turn was associated with lower drinking risk.