Primary Care Health Professional Shortage Area Designations Before and After the Affordable Care Act’s Shortage Designation Modernization Project

This cross-sectional study evaluates whether the Patient Protection and Affordable Care Act (ACA) Shortage Designation Modernization Project is associated with changes in primary care health professional shortage area (PC-HPSA) designations.


Introduction
Primary care physician (PCP) supply in the United States is unequal and diverging, with PCP density in urban counties double that of rural counties, and more than 50% of rural counties losing PCPs in the past decade. 1 To help reverse this pattern, the federal government provides incentives, such as loan repayment programs, bonus payment programs, or programs to recruit noncitizen foreign medical graduates, for physicians practicing in primary care health professional shortage areas Care Act. 5 Whether SDMP implementation is associated with changes in PC-HPSA designations and whether these changes accurately reflect county-level physician supply are unknown.

Methods
In this cross-sectional study, we used the Health Resources and Services Administration Area Health Resources Files and extracted county-level PC-HPSA designations, population, and PCP counts

Results
There were 3137 counties with complete data across the observational period (538 non-PC-HPSAs [17%], 1334 partial-county PC-HPSAs [42%], and 1265 PC-HPSAs [40%] beginning in 2010). Countylevel designations changed between 2010 and 2018, with many full counties redesignated as partial-county PC-HPSAs after SDMP implementation (Figure 1). The number of non-PC-HPSA and full-county designations immediately before (2013) and after (2015) SDMP implementation decreased by 8% and 32%, respectively. The number of partial-county PC-HPSAs increased by 29% (Figure 2A), with an increase in the median population-to-PCP ratio for full-county PC-HPSAs greater than the minimum required ratio of 3000 to 1. The population-to-PCP ratio for partial-county or non-PC-HPSAs remained constant ( Figure 2B). Segmented regression estimates aligned with the descriptive findings: a significant increase was found in the population-to-PCP ratio in full-county PC-HPSAs after implementation of the SDMP compared with before implementation (difference: 293 person-to-PCP increase [95% CI, +176 to +410]; P < .001). No other significant findings were found.

Discussion
The Patient Protection and Affordable Care Act has changed the US health care delivery system in many ways that have yet to be evaluated, including streamlining the designation of PC-HPSAs, which may more appropriately incentivize PCPs to practice in underresourced settings. The Shortage Designation Modernization Project implementation coincided with a change in PC-HPSA designations from full-county to partial-county PC-HPSAs, sharpening the geographic focus of the designations to accurately reflect areas with low PCP supply. Additional research is warranted to understand the implications of the SDMP for the distribution of incentive payments, and subsequently PCPs, and to ascertain whether this policy change has effectively redirected resources to underresourced areas. In the future, incorporation of additional deprivation indicators into the PC-HPSA designation process may be needed to better incentivize health care access for patients in areas with high social and medical needs.
This study has limitations, including the use of county-level data, which do not address changes in other types of PC-HPSA designations based on populations or facilities at the subcounty level. We also used physician counts derived from the American Medical Association Physician Masterfile to calculate population-to-PCP ratios, which may overestimate the current number of practicing physicians. 6 However, this overestimation would produce an underestimation of the populationto-PCP ratios, suggesting even greater physician shortages in the full-county PC-HPSAs identified after SDMP implementation.