Provider care segregation and hospital-region racial disparities for carotid interventions in the USA

Background Reasons for racial disparities in the utilization and outcomes of carotid interventions (carotid endarterectomy (CEA) and carotid artery stenting (CAS)) are not well understood, especially segregation of care associated with carotid intervention. We examined patterns of geographic and provider care segregation in carotid interventions and outcomes. Method We used de-identified Medicare datasets to identify CEA and CAS interventions between January 1, 2016 and December 31, 2019 using validated ICD-10 codes. For patients who underwent carotid intervention, we calculated (1) the proportion of White patients at the hospital, (2) the proportional difference in the proportion of White patients between hospital patients and the county, and (3) provider care segregation by the dissimilarity index for carotid intervention cases. We examined associations between measures of segregation and outcomes. Results Despite higher proportions of Black patients in counties with hospitals that provide carotid intervention, lower proportions of Black patients received intervention. The difference in the proportion of White patients comparing CEA patients to the county race distribution was 0.143 (SD 0.297) at the hospital level (for CAS, 0.174 (0.315)). The dissimilarity index for CEA providers was high, with mean (SD) 0.387 (0.274) averaged across all hospitals and higher among CAS providers at 0.472 (0.288). Black patients receiving CEA and CAS (compared with Whites) had reduced odds of discharge home. Better outcomes (inpatient mortality and 30-day mortality) were independently associated with higher proportion of White CAS patients. Conclusion In this national study with contemporary data on carotid intervention, we found evidence for segregation of care of both CEA and CAS.