Diversity in U.S. hidradenitis suppurativa clinical trials: systematic review and meta-analysis

Hidradenitis suppurativa can significantly affect quality of life, yet remains underdiagnosed and undertreated. Research indicates a higher prevalence among Black females, who are frequently underrepresented in clinical trials. To enhance the generalizability of findings, it is imperative that clinical trials include diversity in investigating HS therapies. This study aims to assess the diversity and inclusion of underrepresented groups in Hidradenitis suppurativa (HS) clinical trials in the United States. In this systematic review and meta-analysis, we identified clinical trials regarding HS and its associated therapies, published or completed between 2018 and 2023, from the major medical literature databases MEDLINE (PubMed), Embase (Elsevier) and ClinicalTrials.gov. Using double-blinded procedures, an initial 245 search returns were screened using eligibility criteria and the final sample’s data was extracted using a standardized form. Information on each study’s included participants based on race, ethnicity, sex, and age, along with general trial characteristics was recorded. We then used the Clinical trial Diversity Rating (CDR) framework to evaluate the diversity of the trials. Of 10 eligible studies, half were phase 2 trials, and 6/10 (60%) of the trials were performed at a single site. Our analysis found (6/10, 60%) had an overall CDR rating of Poor for race/ethnicity, with an underrepresentation of Black and Asian and an overrepresentation of white participants. Males and females were adequately represented across the studies. Regarding age, we found that 8/10 (80%) of clinical trials were rated Poor in their inclusion of older adults. In summary, this study noted the underrepresentation of Blacks and Asians relative to white participants in HS clinical trials in the US. We hope these findings encourage policy changes in the recruitment and enrollment of historically minoritized participants to understand better HS treatment, safety, efficacy, and validity of study outcomes.