User Engagement with an STI Prevention App Tailored for Black MSM using PrEP and Willingness to Expand Usage to Doxycycline Post-Exposure Prophylaxis: A Pilot Randomized Trial (Preprint)

BACKGROUND Rates of sexually transmitted infections (STIs) are elevated for Black men who have sex with men (BMSM) and those taking HIV pre-exposure prophylaxis (PrEP), and thus STI prevention strategies are critically important. PCheck is a PrEP adherence app tailored for BMSM PrEP users, adapted with STI prevention features. OBJECTIVE This pilot trial was conducted to assess app acceptability, feasibility, and usability. METHODS We enrolled BMSM PrEP Users ages 18-35 in a randomized controlled pilot study (1:1 randomization, later amended to 2:1). Surveys were administered using questions from validated questionnaires. In-depth interviews (IDIs) were conducted with 12 participants to discuss specific app features and the potential of adapting PCheck for doxycycline post-exposure prophylaxis (doxy PEP). RESULTS From June 2022 to June 2023, 68 BMSM participants were enrolled, with 40 randomized to receive PCheck. Among these, 30 (75.0%) completed the Week 48 survey. Most participants reported that they were mostly or very satisfied with PCheck (19/30, 63.3%) and that PCheck would mostly or very much work for long-term usage (21/30, 70.0%). In IDIs, participants reported enjoying the app, particularly how it increased their accountability. Most participants had not heard of doxy PEP, but all thought it sounded beneficial. All participants thought the app would facilitate doxy PEP use, for example, by providing resources, pill reminders, sexual activity tracking, and general education about this STI prevention strategy. CONCLUSIONS In a small pilot study, results provide encouraging evidence of PCheck’s usability and feasibility, and its potential to be further developed as an app to promote uptake and adherence to doxy PEP. CLINICALTRIAL NCT05395754