Survival Disparity Following Abdominal Aortic Aneurysm Repair Highlights Inequality in Ethnic and Socio-economic Status

Abstract

Objectives: Socio-economic status (SES) and ethnicity have been reported as markers influencing the likelihood of increased mortality. The aim of this study was to investigate how SES and ethnicity impacted patient survival after abdominal aortic aneurysm (AAA) repair.

Methods: Consecutive patients undergoing open and endovascular AAA repair during a 14.5 year period were identified. Ethnicity was defined as recorded on health records and SES (a score of 10, where 1 is least deprived and 10 being most deprived) and was linked to census data. Operative outcomes were reported at 30 days and a medium-term survival analysis used the Cox model to report adjusted hazard ratios (HR).

Results: A total of 6239 patients with a median age of 75 years and 78.7% males were included. The majority (5,654) were identified as New Zealand (NZ) Europeans, with 421 identified as NZ Maori, 97 identified as belonging to a Pacific ethnic group, and 67 identified as an Asian ethnic group. The median survival follow-up period was 5 years and after adjusting for confounders, those who identified as NZ Maori had the lowest survival compared with all other ethnic groups with a HR of 1.46 (95% CI 1.23-1.72). Living in areas of high social deprivation ≥ 7 was an independent predictor of short and medium-term overall mortality when compared with living in deprivation deciles 1 or 2.

Conclusions: Low SES was identified as a marker of risk for all ethnic groups in relation to both reduced short and medium-term survival. However, regardless of SES, NZ Maori had worse overall medium-term survival following AAA repair than the other ethnic groups. Therefore it appears that both SES and being Maori were markers of increased exposure to risk that negatively impact upon survival after AAA repair. There is a need to ensure systemic processes support initiatives that reduce this inequality.

Keywords: Aortic aneurysm; Deprivation; Indigenous; Maori; Outcomes research.