Inclusive Recruitment Strategies to Maximize Sociodemographic Diversity among Participants: A St. Louis Case Study

Background. Sociodemographically diverse study samples are critical for research related to health decision making. However, not all researchers have the training, capacity, and funding to engage research methods that recruit the most diverse populations. Objective and Methods. We used participant-generated data, staff salary data, and participant observation to examine the effectiveness and cost of strategies that we used for screening, enrolling, and retaining a sociodemographically diverse sample for a risk communication and behavior change randomized controlled trial. Results. It took approximately 646 hours to contact 1,626 individuals and enroll 554 participants (505 of whom completed the baseline survey; 45.2% were members of a underrepresented racial/ethnic group, 19.4% had no college education, 49.5% were age 30–49 y). Retention at 90-d follow-up was 93%. The total cost was USD$19,898.50. The average cost was $35.92 per participant enrolled. In-person recruitment was most successful in identifying the largest proportion of screened and eligible participants who were members of underrepresented racial/ethnic populations (32.8% and 27.8%, respectively) and with no college experience (39.7% and 33.5%, respectively); it also had the highest total cost ($8,079.17). Existing research pools identified the largest proportion of younger participants (ages 30–49 y; 39.3% and 43.4% for screened and eligible, respectively). Existing listservs yielded the smallest proportion of individuals with no college experience and the fewest members of underrepresented racial/ethnic populations but had the lowest total cost ($290.33). Newspaper ads identified the fewest younger individuals and also had the highest cost per participant enrolled ($166.21). Word of mouth had the lowest cost per participant enrolled ($10.47). Conclusion. Results help medical decision-making researchers formulate recruitment plans that increase sociodemographic diversity in study samples. We also ask funders to accommodate increased costs required to maximize sociodemographic diversity in medical decision-making research. HIGHLIGHTS: We provide concrete strategies for recruiting, enrolling, and retaining a sociodemographically diverse study sample. We offer cost estimates for all stages of study recruitment and found that in-person recruitment was the most effective, but also the most expensive, way to identify Black participants and participants with no college experience. It is critical for investigators to have access to institutional infrastructure and resources to support conducting research that is inclusive of diverse sociodemographic groups. An intentionally diverse recruitment staff supports a diverse study sample.