Web-based alcohol intervention for nightclub patrons: Opposite effects according to baseline alcohol use disorder classification.

BACKGROUND:
This study aimed to test the effectiveness of a Web-based intervention in preventing alcohol abuse among nightclub patrons.

METHODS:
A probabilistic sample of the patrons of 31 nightclubs in São Paulo, Brazil, was invited to participate in an online screening using the Alcohol Use Disorders Identification Test (AUDIT). A total of 1057 patrons met the inclusion criteria to participate in the randomized controlled trial, with data collection at 0, 3, 6, and 12 months. At baseline, participants were classified into 2 AUDIT score groups: a "high-risk" group (AUDIT ≥8; 44%) and a "low-risk" group (AUDIT <8; 56%). In both groups, the intervention subgroup was exposed once to a personalized normative feedback screen with information on the participant's alcohol consumption and its potential consequences.

RESULTS:
After 12 months, no differences were found between the intervention and the control conditions in either risk group. In the "high-risk" group, there were significant reductions of both the AUDIT score and the prevalence of binge drinking (BD) over time in both the control and the intervention subgroups. In addition, an effect of the intervention was observed at 6 months, i.e., there was an estimated 13% reduction in the AUDIT score in favor of the intervention subgroup (odds ratio [OR] = 0.87; 95% confidence interval [CI]: 0.76, 1.00). In the "low-risk" group, both the control patrons and those receiving the intervention had increased AUDIT scores.

CONCLUSION:
The results suggest that the time effect of participating in the study may have had a beneficial outcome in reducing harmful drinking among patrons in the "high-risk" group. The intervention is not recommended to the "low-risk" group.