Objective: The number of randomized clinical trials (RCTs) with patients with idiopathic inflammatory myopathies (IIMs) has grown exponentially over the last decade. Race, ethnicity, and sex reporting and representation of participants as well as the geographic distribution of enrolling sites in IIM RCTs are unknown. This information can provide critical insights into the current state of enrollment practices and generalizability in IIM RCTs.
Methods: A systematic literature review assessed IIM RCTs published between 2010 to 2023. Sex and gender reporting was analyzed per Sex and Gender Equity in Research guidelines. Appropriate reporting of race and ethnicity was defined as reporting them for all trial participants. Countries were categorized based on the Human Development Index. US enrollment sites were grouped using the National Center for Health Statistics Urban-Rural Classification Scheme and medically underserved areas (MUAs).
Results: Of the 19 RCTs included, race was appropriately reported in 58%. Black, Asian, and Hispanic or Latino participants represented 3%, 7%, and 2% of the enrollees, respectively. Ethnicity was only reported in 26% of RCTs, and 16% conflated race and ethnicity. Temporal trends showed encouraging results for race and ethnicity representation. Most trials (90%) had greater than 45% women participants. Geographic regions of sites included North America, Europe, Asia, and Australasia, with no sites in South America or Africa. The majority of US sites were located in large metropolitan areas, whereas none were in nonmetropolitan areas, and only 31% in MUAs.
Conclusion: Racial, ethnic, and geographic representation in IIM RCTs remains a critical issue. Inadequate reporting of race and ethnicity and limited sociodemographic and geographic representation of participants raise concerns about the generalizability of findings of IIM RCTs.
© 2025 American College of Rheumatology.