Payer Status, Preoperative Surveillance, and Rupture of Abdominal Aortic Aneurysms in the US Medicare Population

BackgroundTo determine the factors contributing to increased rate of ruptured abdominal aortic aneurysms (AAAs) for elderly poor patients.MethodsMedicare claims were analyzed for patients who underwent AAA repair from 2006 to 2009 with preoperative abdominal imaging. Repair for ruptured versus intact AAAs was our primary outcome measure. We used logistic regression to determine the relationship between Medicaid eligibility and the risk of rupture, sequentially adding variables related to patient characteristics, socioeconomic status, receipt of preoperative AAA surveillance, and hospital AAA volume. We then estimated the proportional effect of each factor.ResultsNo differences in rupture were observed in women based on payer status. Medicaid-eligible men were more likely to present with ruptured AAA (odds ratio [OR] 2.42, 95% confidence interval [CI] 1.65–3.52). After adjusting for patient and hospital factors, the poor remained at higher risk for rupture (OR 1.5, 95% CI 1.10–2.26). This disparate risk of rupture was more commonly observed in hospitals treating a higher proportion of Medicaid-eligible patients. We estimate that 36% of the observed disparity in rupture for the elderly poor is explained by patient factors, 27% by gaps in surveillance, 9% by hospital factors, and <1% by socioeconomic factors.ConclusionsIncomplete preoperative surveillance is a key contributor to increased rupture of AAA in the elderly poor. Efforts aimed at improving disparities must include consistent access to medical care.