Assessing Geographic Access to Primary Care Across the Urban-Rural Spectrum in Wisconsin: A Space-Time Geography Approach
Malia Jones, PhD, MPH
William R. Buckingham, PHD
Caitlin McKown, BA
Applied Population Lab
University of Wisconsin-Madison
Background
Access to primary care providers is a central component of health and preventive health care, and is associated with health indicators such as hospitalizations, mortality and morbidity. Geographic access—availability of a provider within a reasonable distance—is an important aspect of access, and has been identified as a major barrier to health promotion in rural areas in the United States and elsewhere. Many parts of rural Wisconsin are currently facing rapid aging because of a double migration process: rural counties are losing younger residents to outmigration, while retiring baby boomers are moving into rural recreational areas. In 20 years, some parts of Wisconsin are projected to have median ages that are extreme for the United States. These aging populations will place high demand on local health care services.
Methods
For federal funding purposes, access to primary care in rural areas is assessed by the Health Resources and Services Administration using relatively simple patient-to-provider ratios within county, zip code, or other administrative units. Here, we present an adaptation of a more sophisticated approach to examine the present accessibility of primary health care for the population of Wisconsin. The two-step floating catchment area approach is method that considers both spatial and temporal factors. Using a database of primary health care providers that we developed, we calculate distance-or-time-based catchment areas around physician and population locations, and use these relationships to create a cumulative physician-to-population ratio for each population center. Because people in rural areas are generally willing to travel longer distances to access services, catchment area sizes are sensitive to the urban-rural continuum, an important and novel consideration. A distance-decay function reduces the influence of arbitrary boundaries, a problem with other methods.
Results
We present results showing that a substantial area of Wisconsin currently lacks adequate access to primary care, and that these areas tend to be older and more rural than the state as a whole. Using population projections, we estimate that these primary care shortage areas will get worse in the absence of policy supporting improving access.
Conclusions
We conclude that policy approaches to improving access to primary care in addition to are warranted, particularly as rural Wisconsin faces the aging and retirement-related migration of the baby boom population.
Future Directions
Finally, we present future directions for this project-in-progress, including plans to scale up our measure of geographic access to coverage for the entire United States.