Geographic Health Disparities Affect Access to Clinical Trials

“Zip code has a greater impact on your health than your genetic code,” Ireland said, noting that for those with lower socioeconomic status, geography matters. Between 2003 and 2007, the life expectancy varied by as much as 33 years between census tracts in Boston. The area with the lowest life expectancy—58.9 years—came in shorter than that of many third-world countries.

The following play a role in health and premature death:

• Behavioral patterns: 40%
• Genetic predisposition: 30%
• Social circumstances: 15%
• Healthcare: 10%
• Environmental exposure: 5%

Health is more than just healthcare resources, Ireland said: it includes behavior, nutrition, and environment. Geographic location can impact access to affordable food and safe water, air quality, and quality housing. Health is linked to the housing community, including transportation, walkability, violence, accessible healthcare providers, and parks and outdoor spaces.

Ireland then presented some U.S. health statistics:

• Life expectancy ranks last for men and second to last for women among the 17 wealthiest countries.
• Infant mortality ranks last among most advanced countries.
• Healthcare outcomes are 27th among the 34 most developed countries.
• Latinos and African Americans experience 30%–40% poorer health outcomes than Caucasian Americans.
• Patients living in low-income neighborhoods are 10 times more likely to undergo limb amputation related to diabetes.
• Breast cancer mortality rate for African Americans is 50% higher than for Caucasian women.

Despite this, Ireland said that people have opportunities to improve their health outside of the physician’s office. Researchers at Harvard found that factors such as proximity to major roadways and supermarkets, exposure to UV light, and walkability can have long-term positive health effects. The United Nations found that 54% of the world’s population lives in urban areas, and that number is expected to increase to 66% by 2050, demonstrating the impact community-level health policy implementations can have.

Ireland reported that most of the intervention resources are aimed at counseling, education, and clinical interventions. But more focus should be on long-term protective measures, encouraging default healthy decisions, and socioeconomic factors.

Next, Bruner discussed a program (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4605855/) she and colleagues developed to assess how accrual to clinical trials is related to U.S. minority population density relative to clinical trial site location and distance traveled to Radiation Therapy Oncology Group (RTOG) clinical trial sites. They tracked addresses and zip codes for RTOG member sites between 2006 and 2009. Of the 4,913 U.S. patients with complete data, patients traveled a median of 11.6 miles to participate in clinical trials. Caucasian participants traveled statistically longer distances (12.9 miles; p < 0.0001), followed by Latinos (8.22 miles), and African Americans (5.85 miles).

“Travel distance is an important factor in general healthcare access, so it is not surprising that it would be important, albeit neglected, in clinical trial participation,” she said.

Bruner said that future studies should assess access to a personal vehicle, reliance on family and friends for transportation, use of public transportation, and cost of transportation. “With a greater understanding of travel burden for clinical trial participants, we can alter outreach efforts to include strategies to minimize travel burden for more minorities to help improve cutting-edge cancer clinical trials access,” Bruner concluded.