To the Editor:
Atopic dermatitis (AD) affects an estimated 7.2% of adults and 10.7% of children in the United States; however, AD might affect different races at a varying rate.1 Compared to their European American counterparts, Asian/Pacific Islanders and African Americans are 7 and 3 times more likely, respectively, to be given a diagnosis of AD.2
Despite being disproportionately affected by AD, minority groups might be underrepresented in clinical trials of AD treatments.3 One explanation for this imbalance might be that ethnoracial representation differs across regions in the United States, perhaps in regions where clinical trials are conducted. Price et al3 investigated racial representation in clinical trials of AD globally and found that patients of color are consistently underrepresented.
Research on racial representation in clinical trials within the United States—on national and regional scales—is lacking from the current AD literature. We conducted a study to compare racial and ethnic disparities in AD clinical trials across regions of the United States.
Using the ClinicalTrials.gov database (www.clinicaltrials.gov) of the National Library of Medicine, we identified clinical trials of AD treatments (encompassing phases 1 through 4) in the United States that were completed before March 14, 2021, with the earliest data from 2013. Search terms included atopic dermatitis, with an advanced search for interventional (clinical trials) and with results.
In total, 95 completed clinical trials were identified, of which 26 (27.4%) reported ethnoracial demographic data. One trial was excluded due to misrepresentation regarding the classification of individuals who identified as more than 1 racial category. Clinical trials for systemic treatments (7 [28%]) and topical treatments (18 [72%]) were identified.
All ethnoracial data were self-reported by trial participants based on US Food and Drug Administration guidelines for racial and ethnic categorization.4 Trial participants who identified ethnically as Hispanic or Latino might have been a part of any racial group. Only 7 of the 25 included clinical trials (28%) provided ethnic demographic data (Hispanic [Latino] or non-Hispanic); 72% of trials failed to report ethnicity. Ethnic data included in our analysis came from only the 7 clinical trials that included these data. International multicenter trials that included a US site were excluded.
Ultimately, the number of trials included in our analysis was 25, comprised of 2443 participants. Data were further organized by US geographic region (Northeast, Midwest, South, West, and multiregion trials [ie, conducted in ≥2 regions]). No AD clinical trials were conducted solely in the Midwest; it was only included within multiregion trials.