Do we have enough? Understanding capacity of care using Geoanalytic Spatial Mapping to access care coverage in Northern California post ACA implementation

Understanding capacity is critical in assessing an area’s primary health care system.  The Affordable Care Act aims at assuring California residents have access to health care coverage. However, health insurance coverage does not equate to access to primary care for individuals if there is an inadequate supply of physicians. One existing approach to assess primary health system capacity is based on calculating the ratio of patients to physicians in a geographic area. Advanced approaches compare 1) the population within a given distance of each provider to 2) the providers within a distance of each population location in order to understand population accessibility to health care.  We seek to add to these methodological tools by using an approach to identify locations without sufficient capacity for under-insured patients in the primary health care system.  We used location/allocation modeling tools within a Geographic Information System (GIS) to compare the spatial distribution of primary care physicians to estimated post-ACA Medicare patients at the ZIP code level in several Northern California counties.  Distribution of primary care capacity is based on models of physician FTEs, patient mix, and panel size.  Results show that while some Northern California communities have sufficient primary health care capacity to serve Medicare patients, others have substantial shortages. Results help understand the impact ACA could have on the area, and the potential lack of care available to residents once they secure health coverage. Results are used by area hospital systems for planning of new provider location and building of new medical facilities.