Certain populations are less likely to gain access to ophthalmology clinical trial sites offering care they’d benefit from. Photo: Getty Images.

It’s a central tenet of evidence-based medicine that data from well-designed studies should drive clinical decision-making. However, even the most scrupulously run studies may not yield results that fully reflect the characteristics of patients who live outside the “research bubble” of the northeastern United States, where a disproportionate amount of clinical trials are conducted. Researchers recently found significant geographic and socioeconomic disparities in access to ophthalmology clinical trial sites for rural, non-northeastern and poorer patients and for those on lower education level census tracts and on census tracts with higher levels of self-reported visual impairment. Their results suggest that ophthalmology clinical trials fail to reflect the eyecare needs of all patient populations, specifically those that are underserved.

The team identified the geographic location of Phase III ophthalmology clinical trial sights using clinicaltrials.gov. Driving time from each US census tract centroid to the nearest clinical trial site was calculated using real traffic patterns. Travel data was then crosslinked to census tract-level public datasets. Cross-sectional multivariable regression was used to identify associations between sociodemographic factors and driving time (>60 minutes) from each census tract centroid to the nearest clinical trial site.

There were 2,330 unique clinical trial sites and 71,897 census tracts. The shortest median driving time was to retina sites (33.7 minutes), and the longest median time was to neuro-ophthalmology sites (119.8 minutes). Driving more than 60 minutes was associated with rural tracts, Midwest, South and West vs. Northeast tracts and tracts with higher visual impairment, higher poverty levels and lower education levels.

“Strategies to recruit these patients to clinical trials may need to be multifaceted, including both travel support and educational resources to address skepticism which may be present in communities with low exposure to clinical trials,” the study authors wrote in their paper. “Recognizing patients’ barriers to clinical trial enrolment is the first step in creating effective interventions to increase recruitment of diverse populations.”

Soares RR, Huang C, Sharpe J, et al. Geographic and socioeconomic access disparities to Phase 3 clinical trials in ophthalmology in the United States. Eye (Lond). September 19, 2022. [Epub ahead of print].