Declining early mortality after hip and knee arthroplasty

Abstract

Background: We aimed to measure the period effect (change over time) in 30-day mortality after total hip arthroplasty (THA) and total knee arthroplasty (TKA) using data from the Australian Orthopaedic Association National Joint Replacement Registry. Methods: We performed an observational study using national registry data from all hospitals performing THA and TKA in Australia including people undergoing primary elective conventional THA and TKA for osteoarthritis from 2003 to 2017, inclusive. Data from the Australian Orthopaedic Association National Joint Replacement Registry, the National Death Index and the Australian Bureau of Statistics were used to generate unadjusted 30-day mortality, the incident rate ratio for mortality adjusted for age and gender, and the standardized mortality ratio at 30 days for each year separately. Results: For the years 2003 and 2017, respectively, for THA, the unadjusted 30-day mortality was 0.23% and 0.06%, and the standardized mortality ratio was 1.11 (95% CI: 0.73, 1.49) and 0.38 (95% CI: 0.16, 0.59). The incident rate ratio was significantly higher than the reference year (2017) from 2003 to 2010, and for 2012, 2013 and 2016, decreasing over time. For the years 2003 and 2017, respectively, for TKA, the unadjusted 30-day mortality was 0.17% and 0.08%, and the standardized mortality ratio was 0.84 (95% CI: 0.55, 1.13) and 0.61 (95% CI: 0.38, 0.83). The incident rate ratio was significantly higher than the reference year (2017) from 2003 to 2009 inclusive, decreasing over time. Conclusions: Thirty-day mortality after THA and TKA declined from 2003 to 2017. This may be due to improvements in intra-operative and post-operative patient management.