Nationwide analysis of risk factors for in-hospital mortality in patients undergoing abdominal aortic aneurysm repair

Abstract

Abstract Background There is increasing awareness that women may have worse outcomes following repair of abdominal aortic aneurysm (AAA). The aim of this study was to analyse the association between sex, age and in-hospital mortality after AAA using hospital episode data collected routinely at the nationwide level. Methods Data were extracted from the nationwide statutory Diagnosis Related Group statistics provided by the German Federal Statistical Office. Patients with a diagnosis of intact (non-ruptured) AAA (ICD-10 GM I71.4) and procedure codes (OPS; 2005–2013) for endovascular aneurysm repair (EVAR) (5-38a.1*) or open aneurysm repair (5-384.5, 5-384.7), treated from 2005 to 2013, were included. A multilevel multivariable regression model was applied to adjust for medical risk (using the Elixhauser co-morbidity score), type of procedure, type of admission, and to account for clustering of patients within centres. The primary outcome was in-hospital mortality. Results Some 84 631 patients were identified, of whom 10 039 (11·9 per cent) were women. Women were significantly older than men at admission (median 74 (i.q.r. 69–80) versus 72 (66–77) years; P < 0·001). EVAR was used less frequently in women (48·1 versus 54·7 per cent; P < 0·001). The in-hospital mortality rate was higher in women, overall (5·0 versus 3·1 per cent; relative risk 1·60, 95 per cent c.i. 1·45 to 1·75), and for EVAR (2·8 versus 1·5 per cent; RR 1·90, 1·60 to 2·30) and open repair (6·8 versus 5·0 per cent; RR 1·36, 1·22 to 1·52). In-hospital mortality increased with age and was highest in patients aged over 80 years. In multivariable regression analysis, female sex (RR 1·20, 1·07 to 1·35) and age per 10-year increase (RR 1·83, 1·73 to 1·95) were independent risk factors for higher in-hospital mortality. Conclusion In Germany, women were older when undergoing AAA repair and were less likely to receive EVAR. Mortality rates were higher in older patients and in women, irrespective of the surgical technique used.