Abstract
Purpose :
Diabetic retinopathy (DR), a microvascular complication of the retina from diabetes, is the leading cause of vision loss among working-age adults in the United States, and diabetic macular edema (DME) is the most common cause of vision loss among DR patients. Our aim is to appreciate a greater understanding of DME clinical trial distribution across the US, contribution of different sectors to DME clinical trial sites, and the availability of sites compared to the distribution of diabetic patients in the US. The goal is to highlight disparities and push for greater funding and trial locations in underrepresented regions.
Methods :
This is a cross-sectional retrospective and descriptive epidemiological study of 1810 DME clinical trials across a 20-year period from January 1, 2002 to December 31, 2021. Clinical trials were screened for DME, US trial location, study completion, and > 50 patient enrollment on ClinicalTrials.gov. Clinical trials were stratified into the four US Census Bureau regions and by sector (private, academic, industry). Using one sample t-tests, clinical trial site distribution across the US was compared to diabetes prevalence where the 2021 CDC diagnosed diabetes prevalence among adults 18+ years of age served as a proxy for DME prevalence. Descriptive geographical mapping of clinical trials was created using ArcGIS Pro.
Results :
Of 1810 total clinical trials, the South was the most represented region for trial site location (42.5%) while the least represented region was the Northeast (14.1%) (Figure 1). The majority of trials were held at private clinics and hospitals (56.4%). The remaining sites were either at academic institutions (12.4%), unlabeled sites sponsored by pharmaceutical companies (14.1%), or unknown (17.1%) (Figure 2). Compared to the 2021 CDC diagnosed diabetes prevalence by region, there are significant differences in the location of clinical trial sites in all four US Census Bureau regions (Northeast: t=30.4, df=8, p<0.0001; Midwest: t=68.7, df=11, p<0.0001; South: t=38.6, df=15, p<0.0001; West: t=17.4, df=12, p<0.0001).
Conclusions :
The distribution of DME clinical trials across the US is not reflective of the distribution of diabetic patients across the country. Since the diabetic patient population represents those who are impacted by DME disease burden, it is crucial that trial sites are located in areas accessible to those in need.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.