Importance: Racial, ethnic, and sex disparities exist in US clinical study enrollment, and the prevalence of these disparities in Pediatric Eye Disease Investigator Group (PEDIG) clinical studies has not been thoroughly assessed.
Objective: To evaluate racial, ethnic, and sex representation in PEDIG clinical studies compared with the 2010 US Census pediatric population.
Design, setting, and participants: This cross-sectional analysis examined PEDIG clinical studies based in the US from December 1, 1997 to September 12, 2022, 41 of which met inclusion criteria of a completed study, a study population younger than 18 years, and 1 or more accompanying publication. Data analysis was performed between November 2023 and February 2024.
Exposure: Study participant race, ethnicity, and sex for each clinical study, as collected from peer-reviewed publications, patient-enrollment datasets, and ClinicalTrials.gov.
Main outcomes and measures: Median enrollment percentages of female, White, Black, Hispanic, Asian, and other race participants were calculated and compared with the 2010 US Census pediatric population using a 1-sample Wilcoxon rank test. Proportionate enrollment was defined as no difference on a 1-sample Wilcoxon rank test if P ≥ .05. If P < .05, we determined if the median enrollment percentage was greater than or less than 2010 US Census proportion to determine if enrollees were underrepresented or overrepresented. To calculate the magnitude of overrepresentation or underrepresentation, enrollment-census difference (ECD) was defined as the difference between groups' median enrollment percentage and percentage representation in the 2010 US Census. Compound annual growth rate (CAGR) was used to measure temporal trends in enrollment, and logistic regression analysis was used to analyze factors that may have contributed to proportionate representation outcomes.
Results: A total of 11 658 study participants in 41 clinical studies were included; mean (SD) participant age was 5.9 (2.8) years and 5918 study participants (50.8%) were female. In clinical studies meeting inclusion criteria, White participants were overrepresented (ECD, 0.19; 95% CI, 0.10-0.28; P < .001). Black participants (ECD, -0.07; 95% CI, -0.10 to -0.03; P < .001), Asian participants (ECD, -0.03; 95% CI, -0.04 to -0.02; P < .001), and Hispanic participants (ECD, -0.09; 95% CI, -0.13 to -0.05; P < .001) were underrepresented. Female participants were represented proportionately (ECD, 0.004; 95% CI, -0.036 to 0.045; P = .21). White and Asian participants demonstrated a decreasing trend in study enrollment from 1997 to 2022 (White: CAGR, -1.5%; 95% CI, -2.3% to -0.6%; Asian: CAGR, -1.7%; 95% CI, -2.0% to -1.4%), while Hispanic participants demonstrated an increasing enrollment trend (CAGR, 7.2%; 95% CI, 3.7%-10.7%).
Conclusions and relevance: In this retrospective cross-sectional study of PEDIG clinical studies from December 1, 1997 to September 12, 2022, Black, Hispanic, and Asian participants were underrepresented, White participants were overrepresented, and female participants were represented proportionally. Trends suggested increasing enrollment of Hispanic participants and decreasing enrollment of White participants over time. This study demonstrates an opportunity to advocate for increased enrollment of underrepresented groups in pediatric ophthalmology clinical studies.