Cartographic Mapping and Travel Burden to Assess and Develop Strategies to Improve Minority Access to National Cancer Clinical Trials.

PURPOSE To assess how accrual to clinical trials is related to US minority population density relative to clinical trial site location and distance traveled to Radiation Therapy Oncology Group (RTOG) clinical trial sites. METHODS AND MATERIALS Data included member site address and ZIP codes, patient accrual, and patient race or ethnicity and ZIP code. Geographic Information System maps were developed for overall, Latino, and African American accrual to trials by population density. The Kruskal-Wallis test was used to assess differences in distance traveled by site, type of trial, and race or ethnicity. RESULTS From 2006 to 2009, 6168 patients enrolled on RTOG trials. The RTOG US site distribution is generally concordant with overall population density. Sites with highest accrual are located throughout the United States and parts of Canada and do not cluster, nor does highest minority accrual cluster in areas of highest US minority population density. Of the 4913 US patients with complete data, patients traveled a median of 11.6 miles to participate in clinical trials. Whites traveled statistically longer distances (12.9 miles; P<.0001) to participate, followed by Latinos (8.22 miles) and African Americans (5.85 miles). Patients were willing to drive longer distances to academic sites than community sites, and there was a trend toward significantly longer median travel for therapeutic versus cancer control or metastatic trials. CONCLUSIONS Location matters, but only to a degree, for minority compared with nonminority participation in clinical trials. Geographic Information System tools help identify gaps in geographic access and travel burden for clinical trials participation. Strategies that emerged using these tools are discussed.