Dermatologic Studies Lacking in Diversity Despite Increased Efforts

Vivien Chen, BS

A new systematic review from Florida suggested that the reporting of racial and ethnic data in dermatologic studies since 2010-2015 had become more transparent during 2015-2020. Despite this, investigators added the inclusion of representative patient populations might still be considered inadequate, especially in regard to psoriasis studies.

In recent years, there has been a call to improve upon disparities in diversity and equity in patient’s recruitment for dermatologic research. However, there is currently limited data evaluating the resulting changes as they pertain to patient sex, race and ethnicity.

As such, a team of investigators led by Vivien Chen, BS, Dr. Philip Frost Department of Dermatology and Cutaneous Surgery at the University of Miami Miller School of Medicine, conducted a systematic review that reassessed representation of racial and ethnic minority groups and women in randomized clinical trials published from 2015-2020.

The Methods

Between July 1, 2015, and July 1, 2020, Chen and colleagues performed a systematic literature review through a PubMed database search for all peer-reviewed English-language RCTs. Keywords included alopecia areata, acne, atopic dermatitis, lichen planus, psoriasis, seborrheic dermatitis, and vitiligo.

A total of 1157 articles were identified after the initial screening, and a secondary screening with review of full text excluded studies conducted solely outside the US.

Representations of race and ethnicity as well as sex were presented as counts and percentages for each disease type, funding source, and journal type, and statistical significance of differences in representation was determined by χ2 tests or Fisher exact tests as appropriate with statistical significance set at P ≤ .05.

Studies were considered unrepresentative of race and ethnicity if they included less than 20% ethnically or racially diverse participants (non-White race or Hispanic ethnicity) and as unrepresentative of sex if they included less than 45% female participants.

The Findings

After the secondary screening, a total of 392 randomized clinical trials were included in the study. Of these studies, 139 were conducted exclusively in the US and 253 were conducted partially in the US.

Investigators noted that conclusions regarding representation for vitiligo and seborrheic dermatitis trials were limited due to small sample size.

Race and ethnicity demographic characteristics for at least 1 category were reported in 295 of 392 studies (75.2%) conducted either exclusively or partially in the US, and in 100 of 139 studies (71.9%) conducted exclusively in the US.

Instigators observed that of the 100 studies conducted exclusively in the US that reported race or ethnicity, eczema studies and acne studies were more likely to include at least 20% racially or ethnically diverse patients than psoriasis studies (eczema studies, 27 [71.1%] and acne studies, 17 [53.1%] compared with psoriasis studies, 8 [12.1%]; P < .001).

Additionally, US-based psoriasis studies were least diverse, with only 12.1% of studies (8 of 66) recording at least 20% non-White representation and 85.2% of total reported participants (11277 of 13238) being White.

Regarding female representation, 41.3% of articles (162 of 392) included at least 45% female representation. Furthermore, rheumatology journal articles were more likely to have at least 45% female representation than dermatology or general medicine articles (rheumatology journal articles, 44 [83.0%] vs dermatology, 38 [59.4%]) and general medicine, 14 [45.2%]; P < .001), and acne clinical trials were more likely to have at least 45% female representation than psoriasis trials (acne clinical trials, 40 [75.5%] vs psoriasis trials, 79 [29.5%]; P < .001).

In comparison to a study conducted from 2010-2015, reporting for race and ethnicity in US studies had increased from 59.8% to 71.9% (P = .05). However, the proportion of reporting articles including at least 20% non-White representation remained unchanged at 38.1%, with 37 of 97 reporting RCTs in 2010-2015 and 53 of 139 reporting RCTs in 2015-2020 (P = .99).

“Dermatologic research has expanded significantly within the last 5 years in other areas including hidradenitis suppurativa, prurigo nodu- laris, and frontal fibrosing alopecia,” the team wrote. “As such, future studies on clinical trial patient representation should similarly extend to encompass other dermatologic conditions.”