Exploring Socioeconomic Disparities in Outcomes and Follow-up After Endovascular Treatment of Abdominal Aortic Aneurysms among Medicare Beneficiaries.

Abstract

Objective: Socioeconomic disparities are known to contribute to adverse outcomes after surgery; however, the role of individual wealth and neighborhood environment on both follow-up and outcomes following EVAR are not well understood.

Methods: We included all fee-for-service Medicare beneficiaries ≥66 years who underwent infrarenal EVAR with a bifurcated endograft for intact AAA from 2011-2019. Patients were divided into cohorts using dual enrollment in Medicare/Medicaid (vs. Medicare only) as a measure of individual wealth and residence in a distressed community (vs. non-distressed community) as a measure of regional wealth (as defined by the Distressed Community Index, DCI). The primary outcome was the composite of late aneurysm rupture, aortic reintervention, conversion to open repair, or all-cause mortality at 9 years. The cumulative incidence of the primary composite outcome was determined using Kaplan Meier methods and compared across groups using log-rank tests.

Results: Of 111,381 patients who underwent EVAR, 9,991 (9.0%) were dual-enrolled in Medicare/Medicaid, and 22,902 (21%) lived in distressed communities. A higher incidence of the primary outcome was observed in dual-enrolled vs. Medicare-only patients (83% vs 72%, hazard ratio (HR) 1.42[95% Confidence interval (CI) 1.38, 1.47] p<.01) and in those living in distressed vs. non-distressed communities (75% vs 72%, HR 1.09[1.06,1.11] p<.01). After adjustment for comorbidities and other disparity measures, the association between dual enrollment or DCI and the primary outcome was attenuated but remained significant (aHR 1.19 [95%CI 1.15, 1.23], aHR 1.03 [95%CI 1.00,1.05], respectively). When mortality was removed from the primary outcome, the relationships between dual enrollment or DCI and the composite outcome were no longer significant after adjustment (aHR 1.02, [0.93, 1.13], aHR 0.95, [0.89, 1.05]). Among EVAR-specific secondary outcomes, rates of 9-year all-cause mortality and late rupture were higher in dual-enrolled vs. Medicare-only patients, and mortality rates were higher in distressed vs. non-distressed patients. In addition, both dual-enrolled and residents of distressed communities had lower rates of EVAR-related office visits and AAA-related imaging in follow-up and higher rates of emergency department visits.

Conclusion: Among Medicare beneficiaries who underwent EVAR for AAA, socioeconomically disadvantaged beneficiaries had a higher incidence of the primary composite outcome, driven primarily by higher all-cause mortality. This study highlights the need for interventions targeted at improving access to appropriate disease surveillance and management of comorbidities for patients who are most vulnerable.