Article Title

Assessing the Capacity of Primary Care Providers to Care for Vulnerable Populations After the Affordable Care Act Using Geoanalytical Spatial Mapping in a Large Hospital System in Northern California

Publication Date



Affordable Care Act, GIS mapping


Background/Aims: The Affordable Care Act (ACA) was enacted to provide increased health care access to uninsured populations, many of whom represent the most vulnerable communities. Health insurance coverage does not automatically equate to access to health care. Understanding where capacity shortages are most pronounced, especially for low-income residents, gives community benefit professionals tools to make impactful, strategic decisions to facilitate the expansion of capacity in the most underserved communities.

Methods: Total number of Medi-Cal beneficiaries for Sutter’s 23 counties pre- and post-ACA was estimated using California Department of Health Care Services state statistics. Total number of primary care physicians (PCP) was obtained from an online database through a customized search of primary specialties that included family medicine, general practice, internal medicine, obstetrics and gynecology, and pediatrics. Each physician was researched to establish accepted insurance types and eligibility criteria. We compared the distribution of PCP capacity and Medi-Cal populations at the ZIP code level using the allocation tools for ArcGIS geoprocessing toolbox with ESRI’s ArcGIS 10.1 geographic information systems (GIS) software and the Network Analyst extension.

Results: Approximately 36.5% of the uninsured population became Medi-Cal eligible following ACA implementation for the Sutter communities. This location/allocation model identified the number of Medi-Cal patients per ZIP code that could not be assigned to any PCP because of the capacity limit for any PCP that was both within the county and within a 30-minute drive time. A series of maps were made that show the number of underserved patients within a 30-, 45- and 60-minute drive time of each of Sutter’s 24 hospitals. There is a considerable clinician shortage and a substantial number of people who do not have a medical home post-ACA. Within Sutter Health’s 23 counties, approximately 2.1 million residents will be enrolled in Medi-Cal post-ACA, with approximately 610,000 (29%) of these without access to a PCP.

Conclusion: While many Northern California communities have sufficient primary care, others have substantial shortages. Among nationally high emergency room usage for low acuity care, results of this analysis are being used by Sutter Health to facilitate the expansion of primary care capacity into these highly vulnerable communities.




June 30th, 2016


August 12th, 2016