Fewer Insurers and Physicians Available in More Diverse Racial and Ethnic Populations

Sebastian Linde, PhD

A new investigation into healthcare availability across the United States suggested that strategic decisions enacted by insurers could contribute to markets with higher racial or ethnic minority populations having systematically fewer participating insurers and a higher prevalence of local physicians not included in coverage networks.

Investigators suggested the findings called for examination of potential insurance redlining within Affordable Care Act (ACA) marketplaces.

In recent years, the issue of structural racism has become more widely considered as an important social risk factor and an impactful to poor health outcomes in historically marginalized communities.

Recent research indicated that those living in historically disadvantaged areas across the country experience continual effects of discriminatory practices such as redlining.

Investigators suggested that the practice of insurance redlining could be manifesting itself via ACA health exchanges, thus warranting critical examination into whether current strategic considerations perpetuate structural inequities.

The team, led by Sebastian Linde, PhD, of the Medical College of Wisconsin, examined 2 hypothesis, including a significant negative association between county-level proportion of non-Hispanic Black individuals and insurer market participation and a significant negative association between the proportion of non-Hispanic Black individuals and the inclusion of local physicians in insurance networks at the census tract level.

Linde and colleagues combined data from a variety of sources to construct 2 analysis samples, the first of which came from the Health Insurance Exchange Compare Public Use Files from the HIX Compare Individual Market database for 2014.

Through these samples, investigators identified insurers’ county-level market participation in 34 states within the ACA marketplace, which were combined with county-level demographic data via the County Health Rankings Project.

The final study featured a total of 2270 counties. The mean age of 23% of the population of featured counties was 18 years and younger, and a mean of 11% of the population had non-Hispanic Black race and ethnicity.

Meanwhile, the second data set featured census tract data from the US Census Burea and public health data from the US Centers for Disease Control and Prevention PLACES databases.

From there, available data were linked with plan-specific data from the Leonard Davis Institute national database of physician networks in 2014.

Investigators examined 16,006 – 25,096 census tracts, and observed that a 1-SD increase in the county non-Hispanic Black population was associated with a 14.1% reduction in the number of insurers (P<.001).

Additionally, a 1-SD increase in the non-Hispanic Black population was associated with a 2.3% reduction in available insurers (P=.04).

Meanwhile, a 1-SD increase in the non-Hispanic Black population was associated with a 15.8% (marginal effect size, −0.32 [0.01]) (P < .001) to 24.7% (marginal effect size, −0.14 [0.02]) (P < .001) reduction in the physicians’ network participation depending on their specialty for practitioners network breadth inclusion.

Adjusting for additional state fixed effects resulted in estimates of 6% (marginal effect size, −0.08 [0.01]) (P < .001) to 13.5% (marginal effect size, −0.12 [0.02]) (P < .001) reductions in practitioner network participation.

“Our findings suggest that strategic decisions by insurers may contribute toward markets with larger racial and ethnic minority populations, and specifically high percentages of non-Hispanic Black residents, having systematically fewer participating insurers and physicians with lower network inclusion,” the team wrote.

The study, "Association of County Race and Ethnicity Characteristics With Number of Insurance Carriers and Insurance Network Breadth," was published online in JAMA Network Open.