Booster effects and mechanisms of web-based personalised normative feedback alcohol intervention for college students: A pragmatic randomised controlled trial

TY - JOUR

T1 - Booster effects and mechanisms of web-based personalised normative feedback alcohol intervention for college students

T2 - A pragmatic randomised controlled trial

AU - Bedendo, Andre

AU - Gaume, Jacques

AU - McCambridge, Jim

AU - Noto, Ana Regina

AU - Souza-Formigoni, Maria Lucia Oliveira

N1 - © 2024 The Author(s). Published by Elsevier B.V.

PY - 2024/7/1

Y1 - 2024/7/1

N2 - BACKGROUND: To evaluate the effects of booster and no booster versions of web-based alcohol Personalised Normative Feedback (PNF) and whether descriptive norms mediated and/or participant motivation moderated the effectiveness of the intervention in real world conditions (i.e. no financial incentives).METHODS: Pragmatic randomised controlled trial with 1-, 3-, and 6-month assessments. Brazilian college students reporting alcohol use in the last 12 months (N=931) were recruited from May/2020 to December/2022 and allocated to 1) No booster/single PNF(S-PNF); 2) Booster/multiple PNF(M-PNF); or 3) Assessment-only control. We applied Helmert coding [1: Any intervention (S-PNF or M-PNF) vs. Control; and 2: S-PNF vs. M-PNF].PRIMARY OUTCOMES: typical number of drinks/week and maximum number of drinks/week; secondary outcomes: drinking frequency and number of consequences. Three-months assessment was the primary interval. Descriptive norms were tested as mediator. Interest, importance, and readiness to change were examined as moderators.RESULTS: Compared to control, any intervention did not influence primary outcomes at 3-months or 6-months, but did at 1-month, when reduced typical drinking (IRR:0.77, 95%CI:0.66;0.90) and maximum number of drinks (IRR:0.69, 95%CI:0.58;0.82). There was an intervention effect on the consequences at 3-months. No differences were observed between S-PNF and M-PNF. No mediation effects were found at 3-months. At 6-months, there was an indirect effect on typical drinking through norms at 3-months (b=-0.82, 95%CI:-2.03;-0.12) and effects on maximum drinks through norms at 1-month (b=-0.54, 95%CI:-1.65;-0.02). No support for moderation was found.CONCLUSIONS: Intervention reduced alcohol drinking at 1 month only and was not effective thereafter. Mechanisms of effect remain unclear.

AB - BACKGROUND: To evaluate the effects of booster and no booster versions of web-based alcohol Personalised Normative Feedback (PNF) and whether descriptive norms mediated and/or participant motivation moderated the effectiveness of the intervention in real world conditions (i.e. no financial incentives).METHODS: Pragmatic randomised controlled trial with 1-, 3-, and 6-month assessments. Brazilian college students reporting alcohol use in the last 12 months (N=931) were recruited from May/2020 to December/2022 and allocated to 1) No booster/single PNF(S-PNF); 2) Booster/multiple PNF(M-PNF); or 3) Assessment-only control. We applied Helmert coding [1: Any intervention (S-PNF or M-PNF) vs. Control; and 2: S-PNF vs. M-PNF].PRIMARY OUTCOMES: typical number of drinks/week and maximum number of drinks/week; secondary outcomes: drinking frequency and number of consequences. Three-months assessment was the primary interval. Descriptive norms were tested as mediator. Interest, importance, and readiness to change were examined as moderators.RESULTS: Compared to control, any intervention did not influence primary outcomes at 3-months or 6-months, but did at 1-month, when reduced typical drinking (IRR:0.77, 95%CI:0.66;0.90) and maximum number of drinks (IRR:0.69, 95%CI:0.58;0.82). There was an intervention effect on the consequences at 3-months. No differences were observed between S-PNF and M-PNF. No mediation effects were found at 3-months. At 6-months, there was an indirect effect on typical drinking through norms at 3-months (b=-0.82, 95%CI:-2.03;-0.12) and effects on maximum drinks through norms at 1-month (b=-0.54, 95%CI:-1.65;-0.02). No support for moderation was found.CONCLUSIONS: Intervention reduced alcohol drinking at 1 month only and was not effective thereafter. Mechanisms of effect remain unclear.

U2 - 10.1016/j.drugalcdep.2024.111337

DO - 10.1016/j.drugalcdep.2024.111337

M3 - Article

C2 - 38823192

SN - 0376-8716

VL - 260

JO - Drug and alcohol dependence

JF - Drug and alcohol dependence

M1 - 111337

ER -