A1 Active components of a web-based personalised normative feedback: a dismantling study
Andre Bedendo1,2, Jim McCambridge2, Jacques Gaume3, Altay A. L. Souza4, Maria L. O. Souza‐Formigoni4, Ana R. Noto4
1Department of Psychobiology, Universidade Federal de Sao Paulo, Sao Paulo, Brazil; 2Department of Health Sciences, University of York, York, United Kingdom; 3Alcohol Treatment Centre, Lausanne University Hospital, Lausanne, Switzerland; 4Department of Psychobiology, Universidade Federal de Sao Paulo, Sao Paulo, Brazil
Correspondence: Andre Bedendo - andrebedendo@gmail.com
Addiction Science & Clinical Practice 2019, 14(Suppl 1):A1
Background: Web-based Personalised Normative Feedback (PNF) show small to moderate effects on alcohol use among college students. However, little is known about its active components. This study evaluated the effectiveness of two components of PNF in reducing alcohol use and consequences among Brazilian college students.
Methods: College students (18–30 years) who reported alcohol use in the last three months (N = 5,476), were included in a three-arm pragmatic randomised controlled trial with 1-, 3-, and 6-month follow-up. Participants were assigned to either: (1) full PNF intervention; (2) Normative feedback (NF) only or (3) Consequences Feedback (CF) only. The primary outcome was AUDIT score; secondary outcomes were number of alcohol-related consequences, drinking frequency, and typical/maximum number of drinks. We used Mixed Models with Multiple Imputation and Pattern-Mixture Model to account for attrition. Post-hoc analysis considered participant interest in knowing more about their drinking.
Results: Single component interventions reduced AUDIT score compared to full PNF, with significant effects for NF at 1-month (b = − 0.23, p = 0.048) and for CF at 3-month (b = − 0.33, p = 0.03). Compared to PNF, NF reduced the number of consequences at 1-month (b = − 0.16, p = 0.001) and drinking frequency at 3-month (b = − 0.42, p = 0.03), but increased the number of typical drinks at 6-month (b = 0.38, p = 0.03). CF reduced drinking frequency at 3-month (b = − 0.37, p = 0.045). Attrition models confirmed all results, except for the NF effect on typical drinks and drinking frequency. Post-hoc analyses indicated the superiority of single components effects among those students not interested in knowing more about drinking.
Conclusions: Findings suggest that individual components were superior to the full PNF intervention, however this effect was mainly driven by a minority of students (around 20%) who were not interested in receiving it.
Trial registration: NCT02058355.