Do risky friends change the efficacy of a primary care brief intervention for adolescent alcohol use?

PURPOSE To determine if peer risk (having friends who drink or approve of drinking) modifies the effects of a computer-facilitated screening and provider brief advice (cSBA) intervention on adolescent alcohol use. METHODS We assessed the intervention effect using logistic regression modeling with generalized estimating equations on a sample of 2,092 adolescents. Effect modification by peer risk was analyzed separately for alcohol initiation (drinking at follow-up in baseline nondrinkers) and cessation (no drinking at follow-up in baseline drinkers) by testing an interaction term (treatment condition by peer risk). Interpretation of the interaction effect was further clarified by subsequent stratification by peer risk. RESULTS The intervention effect on alcohol cessation was significantly greater among those with peer risk (adjusted relative risk ratios; risk 1.44, 1.18-1.76 vs. no risk .98, .41-2.36) at 3 months' follow-up. There was no such finding for alcohol initiation. CONCLUSIONS Alcohol screening and brief provider counseling may differentially benefit adolescent drinkers with drinking friends.