Assessing recruitment and retention strategies in clinical trials for inequitable populations in systemic lupus erythematosus: A cross-sectional analysis

Background: Systemic lupus erythematosus (SLE) exhibits a mortality rate four times higher in historically marginalized populations compared to the general population. It is essential for clinical trials to accurately represent the disease population to effectively evaluate treatment modalities. However, the current trial design lacks appropriate diversity, limiting the generalizability of results. We aim to assess the recruitment and retention strategies of historically marginalized populations in SLE clinical trials. Methods: In this cross-sectional analysis, relevant clinical trials were obtained in a comprehensive search of MEDLINE (PubMed) and Embase (Elsevier) in May of 2024. Included trials were published between January 1, 2018, and December 31, 2023, with a focus on SLE interventions. Reviewers KR and SS independently performed screening and data extraction via a standardized Google Form. The main outcome measured was the usage of recruitment and retention strategies, concerning under-resourced populations. All statistical analyses were performed via Stata 18 SE. Findings: Our initial database search returned 747 trials, but only 86 were included in this sample. Of these, 4/86 (4.7 %) implemented recruitment strategies while 6/86 (7.0 %) reported the use of specific retention strategies. Nineteen of the 86 studies (22.1 %) reported challenges to the recruitment of inequitable populations, primarily identifying the disproportionate representation of female participants and socioeconomic obstacles as a limitation. Interpretation: Key strengths include a thorough methodology from adherence to PRISMA guidelines and generalizable findings with the inclusion of international trials. Limitations include publication bias and exclusion of trials in non-English languages. Our study highlights the need for practical initiation of effective recruitment and retention strategies that aim to engage historically marginalized populations in SLE clinical trials. Addressing these gaps is necessary to prioritize the participation of inequitable populations, increase standardization of SLE treatments, and improve the relevance of SLE research.