To the Editor A recent study¹ that used Medicare administrative data reported disparities in readmission rates for Black compared with White beneficiaries and notable segregation in the care of Black and White patients among hospitals. These findings necessitate attention to additional structural factors contributing to the observed disparities, extending beyond between-hospital–level segregation to the community and other health system levels.

When comparing hospitals with equitable vs inequitable readmission rates, the authors observed that large, urban, teaching hospitals were more likely to have inequitable readmission rates for Black beneficiaries. These types of hospitals likely have many different medical services, ranging from general to subspeciality care (eg, transplant), with different physicians and other resources by service (ie, nursing expertise, social workers, and other support staff). Segregation of patients by service can contribute to inequities if certain groups have different likelihood of receiving subspecialty care, such as if Black patients with heart failure are less likely to be admitted to a cardiology specialty service.² Even within general medicine, there are often multiple services that provide care for patients. For example, Stanford Hospital has at least 3 distinct general medicine inpatient services, each staffed by different clinicians: resident teams, direct-care teams, and a private medical group that exclusively cares for patients within their health insurance network. As staff and resources for these services differ, health outcome inequities may occur within the hospital.