New Study Identifies Racial Inequality in U.S. Hospital Admissions

Black Medicare patients are disproportionately admitted to lower-quality hospitals, as rated by the Centers for Medicare & Medicaid Services (CMS), despite living closer to higher-rated facilities, according to a study led by Ellesse-Roselee Akré, PhD, assistant professor in Health Policy and Management. The study was published on December 5 in PLOS One.

The new study reveals that residential segregation alone cannot account for unequal access to high-quality health care. The findings suggest structural factors within the health care system—such as referral networks, intake processes, implicit bias, and historical institutional practices—may influence where patients ultimately receive care.

“What we are seeing is segregation within the health care system itself—a sorting of patients of different races, in seen and unseen ways, even within the same neighborhood."

“What we are seeing is segregation within the health care system itself—a sorting of patients of different races, in seen and unseen ways, even within the same neighborhood,” says Akré.

Using 2019 Medicare claims data from more than 2,000 hospitals, the research team developed the Local Hospital Segregation (LHS) index, a new metric that measures how much a hospital’s share of admissions for a racial group—for example, Black patients—differs from that group’s share among all patients who were admitted to any hospital in the hospital’s surrounding market area. The LHS index used statistical modeling, adjusting for residential segregation, ownership, teaching status, Medicare Disproportionate Share Hospital status (hospitals serving a higher-than-average share of low-income patients), market size, and region. Sensitivity analyses were conducted by market size, admission type, and alternative market radius.

The study found that a 10-percentage-point increase in the LHS index corresponded with a 79% higher likelihood that Black Medicare patients would be admitted to a 1- or 2-star hospital under the CMS quality rating system. These hospitals consistently scored lower on safety, timeliness, patient experience, efficiency, and readmission measures.

The study found that a 10-percentage-point increase in the LHS index corresponded with a 79% higher likelihood that Black Medicare patients would be admitted to a 1- or 2-star hospital under the CMS quality rating system.

“Even when hospitals of differing quality sit just miles apart, clear patterns of racial sorting emerge,” says Akré. “That sorting has measurable consequences for both immediate and long-term health outcomes of Black Medicare patients. They face higher risks of death, complications, readmissions, and preventable safety events—all of which likely widen existing health disparities.”

The disparities persisted even among Medicare beneficiaries who have similar coverage and provider access.

The new findings challenge common assumptions about access, says Akré. “Proximity to a high-quality hospital does not guarantee admission. To advance equity, we must examine the systems and incentives that guide where patients are directed.”

The researchers note that the LHS index can serve as a meaningful benchmark for policymakers, health systems, and researchers seeking to identify and address inequities in hospital utilization. Future work may include qualitative studies exploring patient trust, cultural experiences, and perceptions of hospital environments, as well as investigations into referral practices and network design.

“Hospitals cannot control where people live, but they can control how they receive them,” Akré says. “Local hospital segregation is measurable, and its consequences are significant. Achieving health equity requires not only improving hospital quality but also transforming the pathways that steer patients to care.”

This study has some limitations. Claims data were only for inpatient admissions, so they may not fully capture differences in underlying health or outpatient care patterns. Some hospitals had missing data for group scores, and quality was measured as an overall average, which may mask differences in care between Black patients and others.

“The Association Between Local Hospital Segregation and Hospital Quality for Medicare Enrollees” was co-authored by Ellesse-Roselee Akré, Deanna Chyn, Heather A. Carlos, Amber E. Barnato, and Jonathan Skinner.

This study was funded by the National Institute on Aging (P01AG019783) and GeoSpatial Resource, a section of the Biostatistical and Bioinformatics Shared Resource at the Dartmouth Cancer Center with NCI Cancer Center Support Grant 5P30CA023108.