The mChoice App, an mHealth Tool for the Monitoring of Preexposure Prophylaxis Adherence and Sexual Behaviors in Young Men Who Have Sex With Men: Usability Evaluation.

Background: Mobile health (mHealth) apps provide easy and quick access for end users to monitor their health-related activities. Features such as medication reminders help end users adhere to their medication schedules and automatically record these actions, thereby helping manage their overall health. Due to insufficient mHealth tools tailored for HIV preventive care in young men who have sex with men (MSM), our study evaluated the usability of the mChoice app, a tool designed to enhance preexposure prophylaxis (PrEP) adherence and promote sexual health (eg, encouraging the use of condoms and being aware of the partner's HIV status and PrEP use). Objective: This study aimed to apply systematic usability evaluations to test the mChoice app and to refine the visualizations to better capture and display patient-reported health information. Methods: Usability testing involved heuristic evaluations conducted with 5 experts in informatics and user testing with 20 young MSM who were taking or were eligible to take PrEP. Results: End users demonstrated satisfaction with the appearance of the mChoice app, reporting that the app has an intuitive interface to track PrEP adherence. However, participants highlighted areas needing improvement, including chart titles and the inclusion of "undo" and "edit" buttons to improve user control when recording PrEP use. Conclusions: Usability evaluations involving heuristic experts and end users provided valuable insights into the mChoice app's design. Areas for improvement were identified, such as enhancing chart readability and providing additional user controls. These findings will guide iterative refinements, ensuring that future versions of the app better address the needs of its target audience and effectively support HIV prevention.