Local Economic Inequality and the Primary Care Physician Workforce in North Carolina

Discussion

Limited access to primary care is one of the mechanisms proposed to explain the association between economic inequality and poor population health.²⁹ In this study, we used a within-county longitudinal design to demonstrate that as economic inequality increased, the number of PCPs per capita declined in a southeastern state in the United States. Within specialty-specific analysis, this pattern was observed for family medicine physicians and not for pediatricians. In addition, we observed a concerning trend wherein increasing pediatric populations within a county were accompanied by a decrease rather than increase in the per-capita pediatrician workforce. These 2 specialties (ie, pediatrics and family medicine) were chosen for further individual investigation due to their size, ease in identifying general practitioners, and importance in the context of the state refusal to expand Medicaid. Building on prior cross-sectional analyses of income inequality and population health, our study disentangles the longitudinal association between these factors from cross-sectional differences in the concentration of physicians between rural areas (which tend to have lower levels of inequality) and urban areas (where inequality tends to be higher).¹⁴ With the economic shock of the COVID-19 pandemic exacerbating the pre-existing trend toward greater economic inequality, further work is needed to understand how the PCP workforce, especially the workforce of family medicine physicians, can be preserved and expanded to meet the health needs of disadvantaged communities.³⁰

At the national level, the United States is expected to experience a shortage of 21,400-55,200 PCPs by 2033, with poverty and rurality influencing this shortage.^31,32 The PCP shortage is also observed internationally. In many Organization for Economic Cooperation and Development countries, a component of this shortage can be attributed to a decline in interest of pursuing primary careers.^33⇓–35 Because it is challenging to quantify the rate at which practitioners of traditional primary care specialties continue to semispecialize, the extent of this shortage may be underestimated.³⁶ Impoverished urban areas may be experiencing particularly rapid exacerbation of the PCP shortage,³⁷ but the negative effects of PCP shortage may be especially felt in rural areas due to their historic experience of poor health outcomes and lack of access to medical care. Rural areas are consistently documented to have worse population health indicators as well as limited access to mental health services, decreased testing for chronic disease, and increased risk of lacking a usual source of health care.³⁷

In North Carolina, our study shows that a higher proportion of urban counties experienced an increase in inequality. However, the magnitude of this increase was greater in the rural counties where inequality increased over the study period. Rural counties with growing inequality may be the most susceptible to large gaps between the demand for primary care and the supply of PCPs. In these counties, exacerbation of the PCP shortage means that already limited health resources would be stretched further, leading to increasing unmet needs for primary and preventive care. As North Carolina has chosen not to expand Medicaid, providers may be hesitant to practice in rural locations due to perceived poor compensation or limited potential to provide care to patients who lack insurance.^38,39

Nonphysician health care providers (ie, physician assistants [PAs] and nurse practitioners [NPs]) have been proposed as a solution to limited access to care, and the supply of providers in these roles may be an important confounder of the relationship between inequality and access to physicians in primary care specialties. Our analysis did not examine PA and NP workforce trends for several reasons. NC Health Workforce, the source for health care workforce data in our study, contains physician workforce data stratified by medical specialty since 2013 but does not include stratification by practice area for PAs and NPs over this entire period. Workforce patterns also vary significantly between physicians and PAs or NPs. Despite enthusiasm for PA-mediated rural primary care, the overwhelming majority of PAs work in nonrural areas, and only a third practice primary care.^40,41 In addition, due to the ease of switching between practice areas and the older age of rural PAs, the percent of PAs in primary care has historically declined at a rate of 0.3% per year.⁴⁰

The increase in income inequality may be considered a symptom of broader social, political, and economic trends with ties to institutional racism, financial deregulation, and the financialization of the economy.^42⇓–44 Historically, periods of low inequality were marked by a rising minimum wage, low levels of unemployment, caps on executive compensation, and widespread collective bargaining.²² In recent years, the share of wealth possessed by the bottom 90% of US households has decreased by approximately 10%, while the wealthiest 1% of the population has increased their wealth by a similar margin.⁴⁵ The COVID-19 pandemic has exacerbated these trends. Massive shifts in the distribution of labor and economic resources have disproportionately disadvantaged ethnic and racial minorities via higher unemployment and decreased access to care.^46⇓–48 As our findings suggest, this acute exacerbation of inequality can potentially have significant and long-lasting adverse consequences for primary care access across the United States.

Despite the timeliness of this analysis, our study is subject to limitations associated with available data and the analytic approach. Census data were obtained from ACS estimates, which are subject to measurement error. To minimize potential for error, we followed Census Bureau recommendations by using the combined 5-year ACS estimates for small geographies such as counties. Decreased access to physician care may also be associated with an increase in access to nonphysician health care provider care. However, in our analysis data on nonphysician primary care providers were not analyzed because these data were not disaggregated by practice type. Furthermore, groupings such as “Primary Care Physicians” were predetermined by NC Health Workforce, and choices for included specialties (eg, the inclusion of obstetrics and gynecology but exclusion of geriatrics) could not be altered. In addition, as with prior observational studies, we cannot identify a causal effect between economic inequality and the size of the PCP workforce. In particular, we were unable to analyze how changes in economic inequality influenced community action or political decisions related to investment in health care, which is the presumed mechanism by which increasing inequality might be associated with decreased PCP availability.

As a further limitation, our data were obtained from a state where some of the fastest growth in inequality has been seen following the Great Recession. As such, our results may not be generalizable to other states in the United States. Generalizability of results is also limited by the model of health care delivery in which general practitioners (GPs), family physicians, and PCPs are often used interchangeably. We did not consider other models of care used outside the United States that require referral from GPs or family physicians to access specialty care. We were also unable to account for reported trends of increasing specialization of family physicians who opt out of full-scope community practice. Our analysis focused on the number of physicians currently in the workforce but not the contribution of community-based medical schools, which are on the frontline of training additional PCPs to meet the health care needs of rural and underserved communities.⁴⁹ Finally, demographic groups with lower average incomes—such as immigrants and workers without a college degree—were most likely to have experienced a loss in job or income due to the COVID-19 pandemic.⁵⁰ As a result, the effects of changes in employment and migration on county-level access to care could not be considered.

The continued rise of economic inequality has been associated with worse health outcomes for people in the US and abroad. As one of a few states in the United States where inequality has continued to increase since the Great Recession, North Carolina's recent experience with rising inequality may foreshadow the impact of growing inequality in the wake of the COVID-19 pandemic. Our fixed-effects analysis specifically evaluated how within-county change in inequality was associated with the PCP workforce, and this association may follow a different pattern from cross-sectional associations comparing different counties, metropolitan areas, or regions. Between 2013 and 2018, our study found that as NC counties became more economically unequal, the per-capita supply of PCPs, and especially family medicine physicians, tended to decrease. Further studies should expand the scope of this analysis by considering the relationship between inequality and the supply of PA and NP primary care providers. While root causes of economic inequality are complex and require interventions at the national scale, these local consequences of economic inequality are a call to action for medical schools in economically unequal states and communities. As location of residency is associated with location of medical practice regardless of rural/urban setting, investment in local primary care physician training may be a method by which communities can support access to primary care that is resilient to trends in economic inequality.^51,52