Post-ACA Trends in the US Primary Care Physician Shortage with Index of Relative Rurality

Index of Relative Rurality (IRR) captures multiple indicators of health care access but is underrepresented in the primary care literature. This research investigates trends in primary care physician supply in US counties with respect to IRR and time since the Affordable Care Act (ACA) was passed.

In this ecologic study, annual ratio of primary care physicians per 100,000 population in US counties was computed for 2010-2017 (3,138 counties over 8 years, N = 25,104). IRR assigned in 2010 placed counties on a rural-urban continuum without the use of a threshold. Primary outcomes were associations of IRR and year with physician ratio and annual change in physician ratio. Multivariable regression models were used to detect associations. The a priori hypothesis was that neither rurality nor year was associated with physician ratio or annual growth.

IRR and year were independently inversely associated with the ratio of primary care physicians per 100,000 and annual growth in physician ratio. A post-hoc analysis of highly rural US states revealed positive median growth rates in some areas.

Despite significant policies in the ACA designed to address the maldistribution of the US primary care physician workforce, more funding and further innovative reforms are urgently necessary to avert a rural workforce crisis in the coming decades. IRR may be a useful continuous, threshold-free metric of rurality in future health services research.