Travel Time to Radiation Oncology Facilities in the United States and the Influence of Certificate of Need Policies

PURPOSE Radiation therapy often requires weeks of daily treatment making travel distance a known barrier to care. However, the full extent and variability of travel burden, defined by travel time, across the nation is poorly understood. Additionally, some states restrict radiation oncology (RO) services through Certificate of Need (CON) policies, but it is unknown how this impacts travel times to care. Therefore, we aim to evaluate travel times to US RO facilities and assess the association with CON policies. METHODS RO facilities were identified from the 2018 National Plan and Provider Enumeration System (n=2,302). Travel times from populated US census tracts to nearest facility were calculated; differences by rurality, area deprivation, and region were computed. Multivariate linear regression was used to estimate adjusted differences in travel time by area characteristics. Logistic regression was used to assess the association of state CON laws with travel time >1-hour. RESULTS Among 72,471 census tracts, 92.4% were within 1-hour of the nearest radiation facility. Among the 12,453 rural tracts, 34.4% were >1-hour. On adjusted analysis, the 3,054 isolated rural tracts had an estimated 58 minute (95% CI 57,59; p<0.001) longer travel time than urban tracts. CON laws decreased rural travel time overall, but the association varied by region with decreased odds of prolonged travel in the South (p<.001), increased odds in the Northeast and Midwest (p<.001), and no association in the West (p=NS). CONCLUSIONS Isolated rural US census tracts, accounting for 9.4 million Americans, have nearly 1-hour longer adjusted travel time to the nearest RO facility, compared to urban tracts. CON laws had region dependent associations with prolonged travel.