Demographic Distribution in DME, RVO Trials Often Underrepresent Racial, Ethnic Groups

Aleksandra Rachitskaya, MD

Disparities between racial and ethnic demographic data in randomized controlled trials (RCTs) of diabetic macular edema (DME) and retinal vein occlusion (RVO) and the United States population according to the 2010 Census were observed in a recent analysis.

The research indicates the need for greater efforts to recruit underrepresented racial and ethnic minorities to improve external validity in DME trials.

“Although the chance that in the US, 2 individuals chosen at random are 6.2% more likely to be from different racial or ethnic backgrounds in 2020 than in 2010, clinical trials continue to underrepresent minorities and possibly contribute to continued health care disparities,” wrote corresponding author Aleksandra Rachitskaya, MD, Cole Eye Institute, Cleveland Clinic Foundation.

Racial and ethnic differences in eye disease prevalence and course of progression suggest the idea that diverse populations have diverse needs. However, disparities in outcomes persist despite the availability of newer treatments and modalities.

Although diabetes-related complications and incidence of RVOs are more pronounced in Hispanic and Black populations, the extent of population-based representation of racial and ethnic groups in RCTs is unknown. Rachitskaya and colleagues performed a retrospective cross-sectional study of the racial and ethnic demographic data of all completed phase 3 RCTs for DME and RVO and compared them to 2010 US Census data.

After selecting completed US-based RCTs that included race and ethnicity information, 15 DME and 8 RVO trials were available for analysis. Each RCT recorded the number and percentage of American Indian or Alaska Native, Asian, Black, Hispanic, Native Hawaiian Or Other Pacific Islander, and White participants.

Investigators compared the demographic distribution of each RCT to the reported distribution of the 2010 US Census demographic data using the x² test. The trials ranged from opening as early as 2004 to ending as recently as 2020.

There were a total of 38 participants (0.4%) who identified as American Indian or Alaska Native and Native Hawaiian or Other Pacific Islander, with groups combined due to low numbers. There were 415 Asian participants (4.4%), 904 Black participants (9.6%), 954 Hispanic participants (10.1%), and 7613 White participants (80.4%).

Comparatively, the 2010 US Census data reported that 1.1% of the population self-reported as American Indian or Alaska Native and Native Hawaiian or Other Pacific Islander, 4.8% self-reported as Asian, 12.6% as Black or African-American, 16.3% as Hispanic, and 63.7% as White.

The data suggest American Indian or Alaska Native and Hawaiian or Other Pacific Islander participants were underrepresented in 2 trials, neither overrepresented or underrepresented in 20, and not represented in any of the included trials.

Meanwhile, Asian participants were underrepresented in 10 trials, overrepresented in 4 trials, and neither overrepresented or underrepresented in 8 trials. In comparison, Black participants were underrepresented in 9 trials, overrepresented in 2 trials, and neither overrepresented or underrepresented in 11 trials.

Further, Hispanic participants were underrepresented in 15 trials, overrepresented in 2 trials, and neither overrepresented or underrepresented in 5 trials. White participants were underrepresented in 2 trials, overrepresented in 14 trials, and neither overrepresented or underrepresented in 7 trials.

Investigators noted the x² values comparing RCT demographic distribution to US 2010 US Census data were significantly different in 22 of 23 included RCTs.

“These findings support the need for more efforts to recruit underrepresented minority groups, which could improve the generalizability of RCT results and in turn help address health care disparities and better serve diverse populations,” Rachitskaya added.

The study, “Representation of Race and Ethnicity in Randomized Clinical Trials of Diabetic Macular Edema and Retinal Vein Occlusion Compared to 2010 US Census Data,” was published in JAMA Ophthalmology.