Skin of Color Representation in Clinical Trials: An Analysis of Clinicaltrials.gov From 2008-2022

The skin of color (SOC) population in the United States (US) is increasing.¹ However, SOC is not well represented in dermatology textbooks, resources, or resident education.² SOC representation in clinical trials is understudied, with only SOC subpopulations being studied in hidradenitis suppurativa and scar formation following laser surgery,^3,4 and there is a lack of research assessing types of diseases investigated in clinical trials and their inclusion of SOC participants.¹ We evaluated the 15 most prevalent skin conditions in patients with SOC and their representation in clinical trials over 12 years.

The top 15 skin conditions affecting SOC (Table 1) were used as search terms on clinicaltrials.gov. Trials conducted from 01/01/2008 to 03/01/2022 were evaluated. Only those with at least one location within the US were included. The aggregate number of trials per disease, number completed, and number with published results were recorded. Race, ethnicity, and Fitzpatrick skin type (FST) were recorded. Studies that did not report race, ethnicity, or FST were excluded. There have been 1,419 clinical trials conducted over the last 14 years regarding the 15 dermatologic conditions. For these conditions, 447 clinical trials were completed with published results, and 278 (62.2%) had specifically identified the race, ethnicity, or FST demographics. Among the 278 trials, there were a total of 84,815 participants stratified by race, 49,883 by ethnicity, and 8,219 by FST (Table 1). 69.1% of participants were White/Caucasian, compared to 16.5% African American/Black participants. This study evaluated the current landscape of SOC representation in clinical trials over the last 14 years. Our data analysis revealed that despite the prevalence of these conditions in SOC, Black/African Americans comprised greater than 50% of participants in only two conditions, keloids (77.9%) and seborrheic dermatitis (55.3%), respectively. Though prior studies evaluating diversity of participants in dermatology clinical trials reported findings of increasing racial diversity¹ (herein 8 conditions had less than 20% participation of Black/African American patients in trials. Decreasing participation of White/Caucasian patients was seen with 69.1% participation, consistent with prior literature.⁵

While representation in clinical trials is multifaceted, it may reflect healthcare disparities for SOC populations, including access to care and opportunities to participate in research trials.¹ Disparities in inclusion makes it difficult to extrapolate the results to SOC patients and can limit therapeutic options and contribute to worse outcomes. This study provides a reminder and catalyst for future clinical trials and research to diversify study populations and report demographic information of their respective participants.