Pragmatic randomized controlled trial of a web-based intervention for alcohol use among Brazilian college students: Motivation as a moderating effect

Abstract Background Web-based personalized normative feedback (PNF) interventions are less effective than their laboratory versions. Participant motivation may account for this reduced effect, but there is only a limited amount of research into the influence of motivation on PNF effectiveness. We evaluated the effectiveness of a web-based PNF in reducing alcohol use and consequences among college students with different motivation levels. Methods Pragmatic randomized controlled trial among Brazilian college drinkers aged 18–30 years (N = 4460). Participants were randomized to a Control or PNF group and followed-up after one (T1), three (T2) and six (T3) months. Outcomes were: AUDIT score (primary outcome), the number of consequences, and the typical number of drinks. Motivation for receiving the intervention was assessed with a visual analog scale (range: 0–10). Generalized mixed models assessed intervention effects via two paradigms: observed cases and attrition models. Results PNF reduced the number of typical drinks at T1 (OR = 0.71, p = 0.002), T2 (OR = 0.60, p  Conclusions The intervention reduced alcohol use, and motivation for receiving the intervention moderated the intervention effects. Motivated students reduced their typical alcohol use, whereas low-motivated students increased their AUDIT score.