Rural representation of the surveillance, epidemiology, and end results database.

PURPOSE: SEER data are widely used to study rural-urban disparities in cancer. However, no studies have directly assessed how well the rural areas covered by SEER represent the broader rural United States. METHODS: Public data sources were used to calculate county level measures of sociodemographics, health behaviors, health access and all cause cancer incidence. Driving time from each census tract to nearest Commission on Cancer certified facility was calculated and analyzed in rural SEER and non-SEER areas. RESULTS: Rural SEER and non-SEER counties were similar with respect to the distribution of age, race, sex, poverty, health behaviors, provider density, and cancer screening. Overall cancer incidence was similar in rural SEER vs non-SEER counties. However, incidence for White, Hispanic, and Asian patients was higher in rural SEER vs non-SEER counties. Unadjusted median travel time was 53 min (IQR 34-82) in rural SEER tracts and 54 min (IQR 35-82) in rural non-SEER census tracts. Linear modeling showed shorter travel times across all levels of rurality in SEER vs non-SEER census tracts when controlling for region (Large Rural: 13.4 min shorter in SEER areas 95% CI 9.1;17.6; Small Rural: 16.3 min shorter 95% CI 9.1;23.6; Isolated Rural: 15.7 min shorter 95% CI 9.9;21.6). CONCLUSIONS: The rural population covered by SEER data is comparable to the rural population in non-SEER areas. However, patients in rural SEER regions have shorter travel times to care than rural patients in non-SEER regions. This needs to be considered when using SEER-Medicare to study access to cancer care.

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 affects travel times to care. Therefore, we aim to evaluate travel times to US RO facilities and assess the association with CON policies. METHODS AND MATERIALS: RO facilities were identified from the 2018 National Plan and Provider Enumeration System (n = 2302). Travel times from populated US census tracts to nearest facility were calculated; differences by rurality, area deprivation, and region were computed. Multivariable 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 3054 isolated rural tracts had an estimated 58-minute (95% confidence interval [CI] 57, 59; P < .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 with urban tracts. CON laws had region-dependent associations with prolonged travel.