US Patient Access to Ophthalmology Clinical Trial Sites Differs by Regions

November 14, 2021
Kevin Kunzmann

A geographical study shows patients in areas with lower income, education, and higher rates of ophthalmic disease may be a greater distance from a trial site.

Access to US ophthalmology clinical trial sites may differ by region, according to new study findings that highlight the disparity of health care access among patients burdened with ophthalmic disease.

In new data presented at the American Academy of Ophthalmology (AAO) 2021 Meeting in New Orleans this week, a team of investigators reported that patients in the Northeast may have better access to phase 3 clinical trial sites for ophthalmic care than other regions. The findings could implicate the validity and value of late-stage clinical trial findings—especially when considering the unique demographic and clinical factors impacting different regions of the US.

Led by Rebecca R. Soares, MD, MPH, the Wills Eye Hospital investigators sought to determine the geographic distribution of ophthalmologic clinical studies across the US. They also aimed to define the predictors of such accessibility for the different regions—an outcome that could help identify at-risk populations less frequently included in late-stage trials.

As they noted, more than 4200 ophthalmologic clinical trials have been conducted in the past decade.

Soares and colleagues sought to define patient travel time to ophthalmologic clinical trial sites for different disease states via data from the US Department of Agriculture Economic Research Service and the Census Bureau. They observed that patients with retina disease had the shortest mean time to clinical trial sites (mean 33.7 minutes; range, 18.7 – 70.1), while neuro-ophthalmology patients had the longest time (mean 119.8 minutes; range, 48.7 – 240.4).

Key region predictors of >60 minute driving times to nearest clinical trial sites included:

  • Rural census tracts (adjusted odds ratio [aOR], 7.60; 95% CI, 5.66 – 10.20; P <.0001)
  • Midwest region (aOR, 1.84; 95% CI, 1.15 – 2.96; P = .01)
  • South region (aOR, 2.57; 95% CI, 1.38 – 4.79; P <.01)
  • West region (aOR, 2.52; 95% CI, 1.52 – 4.17; P <.001)
  • Higher poverty levels (aOR vs first quartile, 2.26; 95 CI, 1.72 – 2.98; P <.0001)
  • Lower education levels (high school aOR vs college Bachelor’s degree or higher, 1.02; 95% CI, 1.00 – 1.03; P = .0072)
  • High visual impairment (aOR, 1.07; 95% CI, 1.03 – 1.10; P <.001)

Though rural location was the most significant predictor of travel distance to ophthalmology clinical trial sites, investigators stressed the significant disparities in access to such sites for census tracts with greater self-reported rates of visual impairment. They noted that clinical trial access is critical for the recruitment, retention, and generalizability of study outcomes.

“It is imperative that clinical trial investigators expand efforts to provide access to patients from rural and other demographically disadvantaged communities,” Soares and colleagues concluded.

The study, “Geographic Access Disparities to Phase 3 Clinical Trials in Ophthalmology in the United States,” was presented at AAO 2021.


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