Assessing if motives-based vignettes influence plans for drinking and alcohol cues: protocol for a randomised controlled trial.

Introduction: In Sweden and the UK, there is a high prevalence of risky drinking, a pattern of drinking associated with adverse consequences. Drinking motives are a proximal predictor of risky drinking and subsequent consequences, suggesting it may be an apt intervention target. Currently, there is a lack of evidence regarding the applicability of motives for intervention efforts. The current study aims to test if motives-based materials are effective in impacting plans for future drinking and reactivity to alcohol-related cues. A secondary aim is to assess individuals' perceptions of risky drinking as outlined by health authorities. The results of the study will inform the design of a motives-based digital alcohol intervention.

Methods and analysis: The study is a three-arm, parallel group, randomised controlled trial. Vignettes will be used to present health information, framed in terms of gains from limiting drinking and losses from excess drinking. Control vignettes will present general health information framed in terms of gains or losses. Proxies for behaviour (intentions and self-efficacy) will be assessed with questionnaire items. A Stroop task will be used to assess reactivity to alcohol cues, and an open-ended item will be used to record perceptions of risky drinking. Outcomes will be contrasted with regression models and estimated using Bayesian inference, while qualitative data will be analysed using thematic analysis within a framework analysis.

Ethics and dissemination: Ethical approval for the study was waived by the Swedish Ethical Review Authority on 16 December 2023 based on participants being anonymous (Dnr. 2023-06474-01). The results of the study will be disseminated in an academic journal and research conferences while also informing the design of a national digital alcohol intervention.

Trial registration number: ISRCTN12456514.