Smartphone application for unhealthy alcohol use: Pilot randomized controlled trial in the general population

Background: There is limited evidence of the efficacy of smartphone applications to reduce unhealthy alcohol use. We tested the efficacy of providing access to a smartphone-based brief intervention for unhealthy alcohol use. Methods: We conducted a two parallel-group randomized controlled trial with follow-up at 6 months, among 977 individuals with an Alcohol Use Disorder Identification Test >= 8 and drinking 15 or more drinks/week. Participants were randomized to receive (or not) access to a smartphone application consisting of personalized feedback, risk assessment and self-monitoring. The primary outcome was the mean number of drinks/week. An intention to treat analysis (ITT) and a per protocol analysis (PP) were conducted. Results: Mean age of participants was 34.2(9.8), 46% were female. The baseline mean number of drinks per week was 28.9(16.7). Results differed by type of analysis: ITT: all 977 participants were included in the analysis. Follow-up rate was 70.7% (n = 691). There was no significant intervention effect: the Incidence Rate Ratio (IRR) (95%CI) for number of drinks per week was 0.93(0.84; 1.03). PP: 702 participants were included in the analysis. Follow-up rate was 78.1% (n = 548). There was a significant intervention effect: the IRR for number of drinks per week was 0.88(0.78; 0.99). Conclusions: Providing access to a smartphone-based brief intervention had no impact on drinking at 6 months and does not appear to be an effective intervention in reducing drinking. Those who downloaded the app appear to benefit from it, nevertheless downloads were limited and further development of similar apps should focus on increasing use.