Background: Over 9 million dual-eligible beneficiaries rely on both Medicare and Medicaid to obtain critical medical services. Medicaid serves as a safety net for low-income Medicare beneficiaries with limited assets; however, it is unknown whether dual-eligible patients have comparable outcomes for procedures to non-dual-eligible Medicare beneficiaries. We compared outcomes by dual-eligible status for patients undergoing carotid endarterectomy (CEA).
Methods: We identified Medicare fee-for-service beneficiaries aged ≥65y who underwent CEA (ICD-9 38.12) from 2003-2010. Beneficiaries with ≥1m of Medicaid coverage were considered dual eligible. We fit mixed models with a random intercept for state and adjustment for demographics, comorbidities, and symptomatic status to assess the relationship between dual-eligible status and outcomes.
Results: A total of 35,832 dual-eligible and 470,134 non-dual-eligible beneficiaries were hospitalized for CEA during the study period. The percentage of dual-eligible CEA patients decreased from 7.9% in 2003 to 6.7% in 2010. Dual eligibles were more likely to be younger, female, of nonwhite race, and living with comorbid conditions (e.g., heart failure, renal failure, diabetes) and symptomatic carotid disease. Dual eligibles had higher 30d composite outcomes including stroke (Table), but the associations with 1y stroke became nonsignificant from 2003-2010. Dual-eligible status was associated with higher 30d and 1y mortality after CEA throughout the study period.
Conclusions: Dual-eligible Medicare-Medicaid beneficiaries had worse short-term stroke and mortality outcomes than other beneficiaries, even after adjustment for comorbidities. Our results indicate a need to understand factors contributing to poorer outcomes. Challenges include the split accountability between the two programs and the diverse sociodemographics, clinical characteristics, and generally poorer health of the patients.