Project SPACE: A Micro-Randomized Trial of Daily Text Messages to Reduce Alcohol Use and HIV Risk Behavior

Project SPACE is a micro-randomized trial evaluating the proximal effects theory-based text messages on alcohol use and sexual HIV risk behaviors among HIV-negative young adult men at the day-level. At baseline, all participants will complete GamePlan, an existing brief online sexual health program. During the subsequent 8-week intervention period, participants will complete a brief morning assessment of the preceding day and will be randomized each afternoon, with equal probability, to receive concrete ("how"), abstract ("why"), neutral control, or no afternoon intervention messages. Participants will also complete pre- and post-intervention measures. The effects of GamePlan are not being separately evaluated in this study.

Inclusion Criteria: * Male sex at birth and currently identify with male gender * Own and use a smartphone that can receive text messages daily * Have tested negative for HIV in the past 24 months * Be willing to consider a change in their drinking behavior * Not currently in a sexually exclusive relationship * In the past three months, the subject must have had at least 3 condomless sexual encounters with men and consumes ≥5 standard alcoholic drinks at least once a week. Exclusion Criteria: * Involved in previous Project SPACE research (i.e., members of the Phase 1 community advisory board or Phase 2 pilot tests) * Participants that have sought treatment for substance use in the past month.