Analyzing Potential Spatial Access to Primary Care Services with an Enhanced Floating Catchment Area Method

Abstract

Floating catchment area methods have been noticeable in the analyses of spatial access to primary care. This paper enhances the existing floating catchment area methods by incorporating a modified Huff Model to articulate population demand on primary care services. The proposed method modifies the Huff Model with a Gaussian distance impedance function, and applies the modified Huff Model in calculating selection probability of floating catchment area method. The Huff Model–based selection probability considers both travel cost and capacity of service sites and therefore can better adjust population demand on primary care services. Furthermore, the proposed method uses the continuous Gaussian function instead of the predefined subzones in previous studies. A case study of the Springfield, MO, metro politan area is conducted by applying the proposed method and previous methods. Results show that the proposed method has moderating effects on measuring spatial access and can overcome the problems of over- and underestimating population demand.