Enrollment of Spanish-speaking Latinx adults in clinical trials: Five lessons learned from a randomized study in substance use treatment.

Latinx individuals are the largest ethnic minoritized group in the United States (US) at 19% of the population. However, they remain underrepresented in clinical research, accounting for less than 8% of clinical trial participants. Consideration of cultural values could help overcome barriers to inclusion in clinical trials and result in better recruitment and retention of Latinx individuals. In this commentary, we describe general guidance on culturally responsive modifications to facilitate the successful recruitment and retention of Spanish-speaking Latinx participants in Randomized Clinical Trials (RCTs) for substance use. We identify five culturally responsive strategies to help enroll participants in RCTs: 1. Create an ethnically diverse research team, 2. Assess available community partners, 3. Familiarize oneself with the target community, 4. Establish confianza (trust) with participants, and 5. Remain visible to participants and staff from recruitment sites. Representation of Latinx individuals in clinical trials is essential to ensure treatments are responsive to their needs and equitydriven. Some of these strategies can further research in helping to promote the participation of Latinx individuals experiencing substance use concerns, including outreach to those not seeking treatment.