Pragmatic randomized controlled trial of an internet-based intervention for alcohol use among college students: perceived motivation as a moderating effect (Preprint)

Abstract

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to evaluate the effectiveness of a web-based personalized normative feedback (PNF) intervention in reducing alcohol use and negative consequences among college students with different motivation levels for receiving the intervention.

: Parallel-group pragmatic randomized controlled trial among college drinkers aged 18 to 30 years from all Brazilian regions. Participants were randomized to a Control (assessment only) or PNF group - 1) drinking profile; 2) normative comparisons; 3) practical costs; 4) alcohol consequences; 5) strategies to decrease risks. Outcomes were: AUDIT scores (primary outcome), the maximum number of drinks, the number of consequences, the frequency of use and number of typical drinks. Motivation for receiving the intervention was assessed with a continuous scale (range=0-10) and students were categorized either as having low motivation (score <3) or being motivated (score ≥3). Students were followed after 1, 3 and 6 months (N=4,460). Generalized mixed models assessed intervention effects via two paradigms: observed cases and attrition models (multiple imputation and pattern-mixture).

Regardless of motivation, the PNF reduced typical drinks after 1 and 3 months and maximum drinks after one month (observed and attrition models), compared to the control. When considering motivation, motivated students (N=3,552) receiving PNF reduced the typical drinks after one (b=-0.51, 95CI:-0.76;-0.27, p<0.001), three (b=-0.60, 95CI:-0.91;-0.29, p<0.001) and six months (b=-0.58, 95CI:-0.93;-0.23, p=0.001), compared to control. Attrition models showed that effects were more robust after 1 and 3 months. In contrast, students with low motivation in the PNF group increased their AUDIT score after 6 months. There were no other significant effects.

The web-based PNF for alcohol use among college students reduced only alcohol use among students, and motivation for receiving the intervention moderated the intervention effects. The intervention reduced the alcohol use only among motivated students, whereas low motivated students had an increased AUDIT score.

NCT02058355. https://clinicaltrials.gov/ct2/show/NCT02058355