ABSTRACT
The Cancer Centers designated by the National Cancer Institute (NCI Centers) and academic medical centers (AMCs) form the “backbone” of the cancer care system in the United States. We conducted a nationwide analysis and generated a high-resolution map detailing spatial variation in the potentially unfulfilled demand for these facilities. A local demand value incorporates spatial access to the facilities and the number of local potential patients. The spatial access was estimated using the two-step floating catchment area method, taking into account both travel time and facility capacity. The travel time was measured using service-area rings created around each facility based on road networks. The facility capacity was measured as the ratio between the bed count of the facility and the number of potential patients in its three-hour catchment. The number of local potential patients was estimated from local demography and standard cancer rates. The demographic information is a combination of LandScan data and U.S. Census data, and the cancer rates are from the Surveillance Epidemiology and End Results. The final demand map shows distinctive patterns in the western and eastern halves of the contiguous United States. The demand in the east is spatially continuous but relatively low, whereas in the west it is sporadic but tends to have high values. We also examined the inherent relationships between several methods for measuring spatial access and found that the differences between them are technical rather than conceptual, which sets a theoretical basis for selecting and adapting those methods.
