Impacts of Residential Segregation and Comorbidity on Racial Disparities in Acute Care Utilization

To examine whether living in highly segregated communities or having comorbidity is associated with an increased risk of acute use of emergency and inpatient services (i.e., acute care utilization [ACU]) among racial minorities.

This longitudinal study included adult patients who underwent health-related social needs screening during their medical appointments within the Mass General Brigham healthcare system from March 2018 to January 2023. Our primary outcome was 180-day ACU defined as a composite outcome of all-cause emergency departments visits or hospital admissions following the most recent screening. Residential segregation was assessed using the index of dissimilarity, with a score of 0.6 or higher indicating extremely high segregation.

Among the 81,571 patients, 38% were non-White, and 28% were Hispanic. Approximately 18% lived in highly segregated communities and 55% had comorbidity. Accounting for demographic and clinical characteristics, Cox regression model found that living in highly segregated areas was generally not associated with the risk of 180-day ACU. Compared to White, non-White had a higher risk of ACU (HR = 1.07 [95%CI: 1.02 - 1.12]). Patients with comorbidity had a higher risk of ACU relative to their counterparts without comorbidity (HR = 1.65 [95%CI: 1.58 - 1.73]). Among patients in highly segregated areas, non-White experienced a 26% higher risk of ACU, compared with White in the same areas. However, for patients with comorbidity, non-White showed only a 5% higher risk of ACU relative to White.

We found an additive effect of residential segregation on racial disparities in ACU. Comorbidity is a risk factor of ACU for all patients.