Abstract Body: Background: Black adults, particularly Black men are underrepresented in cardiovascular research studies, limiting interpretation and generalization of findings, adversely impacting health equity. Analyses of enrollment strategies often focus on recruitment. Retention strategies to optimize study participation among Black adults, specifically Black men are underexplored.

Objectives: To describe retention strategies for Black male participants of a community-engaged hypertension prevention trial.

Methods: Community-to-Clinic Linkage Implementation Program (CLIP) is a cluster-randomized barbershop-based implementation study of hypertension prevention for Black men. Eligible participants (age 18-85 years, blood pressure (BP) <130/80 mmHg), were recruited from 22 Black-owned barbershops in Staten Island, New York City. Recruitment was managed by Community Health Workers (CHWs) from a local service organization. Enrolled participants receive navigation to medical care, social services, and lifestyle coaching. Data collection includes questionnaire completion and BP measurement at time of enrollment, 6, 12, and 18 months. BP change at 12 months is the primary outcome.

Results: We enrolled 425 participants. All 425 participants have reached the 6-month mark since enrollment and baseline data collection. 293 participants completed a 6-month follow-up visit. 12 and 18-month follow-up periods are ongoing with 206 participants completing the 12-month follow-up, and 71 participants completing the 18-month follow-up to date. After experiencing challenges with re-engaging participants for follow-up visits, new retention strategies were informed by input from CHWs, and the community advisory council (CAC) comprised of local leaders and collaborative community partners. Novel strategies included co-management of retention by CHWs and research staff, hiring a retention specialist, outreach to barbershops, evening and weekend appointments, and availability of mobile vans to meet participants at their choice of location.

Conclusions: Retention is a vital component of community-engaged trials and requires creative thinking, flexibility, and cooperation between community and academic partners to optimize outcomes. We offer our experience as an example of real-world strategies for improving retention in a community-engaged trial.