This inequity may be potentiating the underrepresentation of racially minoritized and socioeconomically disadvantaged populations in clinical trials, suggesting that employment of satellite hospitals is needed to expand access to investigational therapies, reported lead author Hassal Lee, MD, PhD, of Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, and colleagues.
“Minoritized and socioeconomically disadvantaged populations are underrepresented in clinical trials,” the investigators wrote in JAMA Oncology. “This may reduce the generalizability of trial results and propagate health disparities. Contributors to inequitable trial participation include individual-level factors and structural factors.”
Specifically, travel time to trial centers, as well as socioeconomic deprivation, can reduce likelihood of trial participation.
“Data on these parameters and population data on self-identified race exist, but their interrelation with clinical research facilities has not been systematically analyzed,” they wrote.
To try to draw comparisons between the distribution of patients of different races and socioeconomic statuses and the locations of clinical research facilities, Dr. Lee and colleagues aggregated data from the US Census, National Trial registry, Nature Index of Cancer Research Health Institutions, OpenStreetMap, National Cancer Institute–designated Cancer Centers list, and National Homeland Infrastructure Foundation. They then characterized catchment population demographics within 30-, 60-, and 120-minute driving commute times of all US hospitals, along with a more focused look at centers capable of conducting phase 1, phase 2, and phase 3 trials.
These efforts revealed broad geographic inequity.The 78 major centers that conduct 94% of all US cancer trials are located within 30 minutes of populations that have a 10.1% higher proportion of self-identified White individuals than the average US county, and a median income $18,900 higher than average (unpaired mean differences).
The publication also includes several maps characterizing racial and socioeconomic demographics within various catchment areas. For example, centers in New York City, Houston, and Chicago have the most diverse catchment populations within a 30-minute commute. Maps of all cities in the United States with populations greater than 500,000 are available in a supplementary index.
“This study indicates that geographical population distributions may present barriers to equitable clinical trial access and that data are available to proactively strategize about reduction of such barriers,” Dr. Lee and colleagues wrote.
The findings call attention to modifiable socioeconomic factors associated with trial participation, they added, like financial toxicity and affordable transportation, noting that ethnic and racial groups consent to trials at similar rates after controlling for income.
In addition, Dr. Lee and colleagues advised clinical trial designers to enlist satellite hospitals to increase participant diversity, since long commutes exacerbate “socioeconomic burdens associated with clinical trial participation,” with trial participation decreasing as commute time increases.
“Existing clinical trial centers may build collaborative efforts with nearby hospitals closer to underrepresented populations or set up community centers to support new collaborative networks to improve geographical access equity,” they wrote. “Methodologically, our approach is transferable to any country, region, or global effort with sufficient source data and can inform decision-making along the continuum of cancer care, from screening to implementing specialist care.”
A coauthor disclosed relationships with Flagship Therapeutics, Leidos Holding Ltd, Pershing Square Foundation, and others.