Investigating Health Inequality in Primary Care Spatial Accessibility Among Races and Ethnicities in King County Using a Geospatial Approach

Distance to healthcare providers is a significant barrier to health care access in the U.S. Healthcare utilization and disease burden have been found to increase as the distance between patients and primary care physicians increase. Although spatial accessibility to primary care resources has been studied using different methods in recent decades, few studies have addressed disparities such accessibility among races/ethnicities. Therefore, we used Enhanced Two-Step Floating Catchment Area (E2SFCA), a gravity-based model that measures spatial accessibility by combining distance decay concept within a certain catchment, 2019 American Community Survey (ACS) 5-year estimates, and primary care physician data to assess the variation of spatial accessibility among races/ethnicities to primary care in King County, Washington. We observed regional differences for spatial accessibility across census tracts. Most census tracts in King County had poorer spatial accessibility than the average. In addition, race/ethnicity of the population and spatial accessibility to primary care physicians was found to be weakly associated to one another. Non-Hispanic Asians had better spatial accessibility, whereas Hispanic and non-Hispanic Native Hawaiian and Pacific Islander populations had less accessibility to primary care providers than people of other races/ethnicities. Area configuration of healthcare resources and improvement targeting of racial/ethnic minorities can help reduce the disparities in spatial accessibility to care.