Stand Down–Think Before You Drink: protocol for an effectiveness-implementation trial of a mobile application for unhealthy alcohol use with and without peer support

Introduction Mobile apps can increase access to alcohol-related care but only if patients actively engage with them. Peers have shown promise for facilitating patients’ engagement with mobile apps. However, the effectiveness of peer-based mobile health interventions for unhealthy alcohol use has yet to be evaluated in a randomised controlled trial. The goal of this hybrid I effectiveness-implementation study is to test a mobile app (‘Stand Down–Think Before You Drink’), with and without peer support, to improve drinking outcomes among primary care patients.Methods and analysis In two US Veterans Health Administration (VA) medical centres, 274 primary care patients who screen positive for unhealthy alcohol use and are not currently in alcohol treatment will be randomised to receive usual care (UC), UC plus access to Stand Down (App), or UC plus Peer-Supported Stand Down (PSSD—four peer-led phone sessions over the initial 8 weeks to enhance app engagement). Assessments will occur at baseline and 8-, 20- and 32-weeks postbaseline. The primary outcome is total standard drinks; secondary outcomes include drinks per drinking day, heavy drinking days and negative consequences from drinking. Hypotheses for study outcomes, as well as treatment mediators and moderators, will be tested using mixed effects models. Semi-structured interviews with patients and primary care staff will be analysed using thematic analysis to identify potential barriers and facilitators to implementation of PSSD in primary care.Ethics and dissemination This protocol is a minimal risk study and has received approval from the VA Central Institutional Review Board. The results have the potential to transform the delivery of alcohol-related services for primary care patients who engage in unhealthy levels of drinking but rarely seek treatment. Study findings will be disseminated through collaborations with healthcare system policymakers as well as publications to scholarly journals and presentations at scientific conferences.Trial registration number NCT05473598.