Providing Higher Resolution Indicators of Rurality in the Surveillance, Epidemiology, and End Results (SEER) Database: Implications for Patient Privacy and Research.

BACKGROUND: The burden of cancer is higher in rural areas than urban areas. The NCI's Surveillance, Epidemiology, and End Results (SEER) database currently provides county-level information on rurality for cancer patients in its catchment area, but more nuanced measures of rurality would improve etiologic and surveillance studies.
METHODS: We analyzed disclosure risk and conducted a sample utility analysis of census tract-level measures of rurality, using (1) U.S. Department of Agriculture's Rural Urban Commuting Area (RUCA) codes and (2) U.S. Census data on percentage of the population living in nonurban areas. We evaluated the risk of disclosure by calculating the percentage of census tracts and cancer cases that would be uniquely identified by a combination of these two rurality measures with a census tract-level socioeconomic status (SES) variable. The utility analyses examined SES disparities across levels of rurality for lung and breast cancer incidence and relative survival.
RESULTS: Risk of disclosure was quite low: <0.03% of census tracts and <0.03% of cancer cases were uniquely identified. Utility analyses demonstrated an SES gradient in lung and breast cancer incidence and survival, with relatively similar patterns across rurality variables.
CONCLUSIONS: The RUCA and Census rurality measures have been added to a specialized SEER 18 database. Interested researchers can request access to this database to perform analyses of urban/rural differences in cancer incidence and survival. IMPACT: Such studies can provide important research support for future interventions to improve cancer prevention and control. ©2019 American Association for Cancer Research.