GEOGRAPHIC ACCESS DISPARITIES TO CLINICAL TRIALS IN RETINOPATHY OF PREMATURITY IN THE UNITED STATES.

Abstract

To identify geographic and socioeconomic variables predictive of residential proximity to retinopathy of prematurity (ROP) clinical trial locations. This cross-sectional epidemiological study used census tract-level data from three national public data sets and trial-level data from ClinicalTrials.gov. Socioeconomic predictors of driving distance and time to the nearest ROP clinical trial location were identified. Primary outcomes were time >60 minutes and distance >60 miles traveled to the nearest ROP clinical trial site. Multivariate analysis showed that residents were more likely to travel >60 minutes to the nearest ROP clinical trial site if they lived in census tracts that were rural (adjusted odds ratio 1.20, P = 0.0002), had higher percentages of the population living ≤ federal poverty level (fourth quartile vs. first quartile, adjusted odds ratio 1.19, P < 0.0001), or had less education (associate vs. bachelor's degree, adjusted odds ratio 1.01, P <0.007). By contrast, counties with higher percentages of births with birth weight <1500 g (adjusted odds ratio 0.88, P = 0.0062) were less likely to travel >60 minutes. Similar variables predicted travel distance. Although counties with higher incidences of very low-birth-weight infants were closer to ROP clinical trial sites, residents living in rural and low-income census tracts had significantly greater travel burdens.