Strategies in Recruitment and Retention of Patients with Sickle Cell Disease for a Single-Site Longitudinal Clinical Trial
Authors: Ayeh Persis , Gandhi Siddhi Naresh , Kaur Charanjit , Vijayan Veena , Amegbeha Anne , Pucka Andrew , O'Brien Andrew Ross Wickman , Harte Steven E , Harris Richard E , Wang Ying 
Published: December 2023

Background
Sickle cell disease (SCD) leads to vaso-occlusive crises (VOCs) and increased healthcare use, disproportionately affecting Black/African Americans. Recruiting and retaining patients with SCD in clinical trials is challenging, with &lt;5% participation rates (Masese et al., 2021) due to complexity, limited awareness, and socio-economic factors (Suarez et al., 2020). Addressing these obstacles to patient recruitment is crucial for advancing SCD research. An estimated 1,695 individuals in various counties in Indiana state are affected by SCD, with 87% being of Black/African American ethnicity (Okolo et al., 2023). The limited number of comprehensive SCD care centers poses significant challenges to recruitment for our ongoing single-site longitudinal trial in Indianapolis to explore the neurobiological mechanisms underlying pain in SCD and the effectiveness of acupuncture. The study consists of 14 in-person visits in 6-8 weeks with 12-month follow-up visits (ClinicalTrials.gov Identifier: NCT05045820). To address these recruitment challenges and ensure meaningful research outcomes, strategic communication, collaboration, and outreach efforts were undertaken to recruit eligible participants and ensure retention. This work aimed to identify factors affecting participant retention rates, including demographic differences between those who completed and those who dropped out.
Study Design and Method
SCD participants were recruited from either local hospitals, including the Indiana University Affiliated Hospitals and local hospitals (such as Eskenazi Hospital, St. Vincent and the Indiana Hemophilia & Thrombosis Center), or external organizations, such as the Martin Center SCD Initiative and community settings, such as churches and community care centers. Various media platforms and events, such as health fairs, campus center events, and church events, were employed to widen our outreach. Local events suggested by participants further reinforced the study's credibility among prospective participants. Retaining participants was achieved through robust and customized strategies throughout the study, including but not limited to 1) personalized real-time communication with the principal investigator, 2) regular check-ins to address concerns, 3) real-time appointment scheduling, rescheduling and reminding system, and 4) hybrid (remote/in-person) follow-up visits. Moreover, additional complementary strategies, such as motivational incentives, transportation vouchers, education platforms, actively listening to feedback, timely communication, and spiritual support were utilized to ensure our complete dedication to their well-being.
Results
We achieved high recruitment and retention rates in our study. So far, our retention rate is 87.1%. Of these, 24.19% completed the entire study, including in-person visits and the 12-month follow-up (n=15). 56.45% of participants are still actively enrolled in the study (n=35), while 12.9% have discontinued participation (n=8). Two participants were deceased. Our utilization of effective recruitment and retention strategies yielded continuous success in actively recruiting and retaining patients with SCD.
Compared to the group of participants who dropped out from the study (n=8 total, female: n=2), participants who completed all scheduled study visits (n=15, female: n=12) were more likely to be female (p = 0.008, independent samples t-test) and have lower disease severity assessed by the frequency of VOCs in the preceding 12 months (p = 0.007, independent samples t-test). Participants recruited from external facilities/events yielded a significantly lower dropout rate than those recruited from local hospitals (p = 0.036, Chi-Square Tests). These results suggest the impact of gender, disease severity, and recruitment source on the retention rate.
Conclusion
The success of SCD clinical trials hinges on implementing personalized recruitment and retention strategies. Further efforts are necessary to explore innovative engagement methods targeting gender and disease-specific challenges while continuously forging solid partnerships with external facilities/organizations.