Adam Gaffney is an assistant professor at Harvard Medical School and a pulmonary and critical care physician at the Cambridge Health Alliance. His research focuses on health care access and disparities (particularly among those with lung disease) and national health care reform.

The disproportionate impact of the COVID-19 pandemic on Black and Hispanic Americans stems, in large part, from greater exposure to the virus at work, home, jails and more. But a new study published in JAMA Network Open suggests unequal access to quality hospital care may also have played a role.

David Asch and colleagues used data on 44,217 Medicare Advantage beneficiaries with COVID-19 who were admitted to 1,188 hospitals in 41 states and Washington, D.C. In age- and sex-adjusted models, Black adults had 23% higher odds of dying within 30 days (or being discharged to hospice) relative to whites, which dropped to 11% when controlling for individual-level socioeconomic and clinical factors (although, as the authors note, such factors can often be caused by underlying structural racism).

The researchers found that the remaining 11% difference in outcomes essentially disappeared once they statistically adjusted for the hospital where each patient received care. The implication is that worse outcomes faced by hospitalized Black individuals may stem (at least in part) from inferior care at hospitals that disproportionately serve Black patients, rather than disparate treatment within a given hospital. 

Why might this occur? For one thing, U.S. health care is highly segregated, and hospitals that serve lower income and minority populations tend to have fewer resources and lower quality. There are also related geographic disparities: Nearly all high-income communities have ICUs, while almost half of low-income communities lack a single ICU bed. Health care infrastructure, in other words, often follows profits — not just community need. Hence, it is plausible that hospitals that serve disadvantaged communities were placed under greater strain during COVID-19, which could have contributed to worse outcomes.

Still, the observational design of the study cannot offer a direct causal link. The investigators also found that adjusting for state of residence had similar effects as adjusting for hospital, and so were unable to disentangle whether disparities existed between states or between hospitals within states. Finally, the investigation was not designed to examine the potential role of biased decision-making among providers.

While more research is needed, the existing evidence at the very least makes clear that there is a discrepancy in the supply of high-quality health care infrastructure, and the need for it, in the U.S. Writing in the Lancet in 1971, Julian Tudor Hart famously referred to this mismatch as the “Inverse Care Law” — the idea that “the availability of good medical care tends to vary inversely with the need of the population served” — a dynamic spurred, he argued, by the operation of free market forces in the health care system.