Minority Patients Significantly Underrepresented in IBD Studies

Investigators examined racial and ethnic representation in IBD clinical trials, assessing trends over time and offering strategies to improve recruitment and design.

Study data published in Gastroenterology highlight significant racial disparities in the clinical research base for inflammatory bowel disease (IBD). In a systematic review of randomized clinical trials of IBD treatments, racial and ethnic minorities were substantially underrepresented in study cohorts. Further, a significant proportion of studies failed to report race/ethnicity data at all.

Investigators systematically reviewed phase 2, phase 3, and open label long-term extension trials assessing the efficacy and safety of United States Food and Drug Administration-approved IBD therapies. The proportion of trials reporting race/ethnicity data was calculated. The number of patients of a particular race or ethnicity were also reported, after excluding studies which did not report race/ethnicity.

The review included 55 studies of 9 distinct therapies, consisting of a pooled cohort of 24,315 participants. Publication year ranged from 1960 to 2020. Thirty-two trials (58.2%) included race data and 10 (19.6%) included ethnicity data. Of the 32 trials reporting race data, 12 (37.5%) reported only the proportion of White patients; the remaining 20 (62.5%) provided a breakdown of race demographics. The mean proportion of White participants was 86.1±8.4% in the 32 trials reporting race data. Among studies which provided a detailed breakdown by race, 85.8±9.1% were White, 2.9±3.3% were Black, 7.1±7% were Asian, and 3.2±2.7% were of another race. Of the 10 trials reporting ethnicity data, all used a binary variable of Hispanic vs non-Hispanic. In these 10 trials, over 95% of the study population was non-Hispanic.

No studies published before 2000 included race/ethnicity data. After 2010, there was a statistically significant increase in the number of studies reporting race or ethnicity data compared with the prior decade (2000-2010) (80% vs 34%; P =.001). Additionally, the number of countries producing IBD-related research increased substantially over this period (8.1±5 vs 25.1±9.5; P <.001). Between the decades 2000 to 2010 and 2010 to 2020, there was also a significant increase in the proportion of Asian participants (2.7±6.8% vs 10.5±5.1%; P =.009).

Results from this analysis underline the lack of race/ethnicity data in the study of IBD therapies. Nearly 40% of included studies did not report race/ethnicity in any capacity, and a further 23% reported only the proportion of White patients. Even among studies reporting race data, the proportions of enrolled minority patients were very low. As the incidence of IBD has been observed to increase in Black and Hispanic patients over time, the inclusion of these groups is necessary to improve treatment quality.

Investigators acknowledge that a lack of subgroup data on racial demographics in each country limits the understanding of recruitment practices in more diverse nations. Additionally, it is unclear how race and ethnicity were determined in each study, limiting the interpretation of these data.

“These disparities are likely due to multiple factors and we propose that greater effort be made at multiple levels for the appropriate participation of all racial and ethnic groups in clinical trials,” investigators wrote. “We believe that these initiatives will enhance equitability of clinical trials in IBD, build trust between providers and patients of diverse backgrounds, further our understanding of disease processes and response to treatment in different patient populations, and ultimately improve the quality of life for all people living with IBD,” they concluded.

Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 


Cohen NA, Silfen A, Rubin DT. Inclusion of under-represented racial and ethnic minorities in randomized clinical trials for inflammatory bowel disease. Gastroenterol. Published online September 21, 2021. doi: 10.1053/j.gastro.2021.09.035

This article originally appeared on Gastroenterology Advisor