Major amputation rates and outcomes for Aboriginal and Torres Strait Islander and non-Indigenous people in North Queensland Australia between 2000 and 2015

Abstract

Background: This study estimated the incidence of major amputation for people in North Queensland, Australia, examined changes in amputation rates over time and investigated survival after major amputation. Methods: This was a retrospective study of patients who underwent a major amputation above the ankle between 2000 and 2015. Major amputation rates and incidence rate ratios (IRR) were calculated using census data to define the at-risk population. Associations between risk factors and calendar year with major amputation were assessed using quasipoisson regression. Kaplan-Meier survival and Cox-proportional hazard analyses estimated the incidence of and risk factors for all-cause mortality. Results: The annual incidence of major amputation was estimated to be greater in Aboriginal and Torres Strait Islanders than non-Indigenous people (IRR 2.75, 95 % CI 1.92 to 3.84). After adjusting for population growth, the annual incidence of major amputations did not change significantly over time for either groups. Aboriginal and Torres Strait Islander people were at greater risk of all-cause mortality after major amputation compared to non-Indigenous people, although this association was not significant after adjusting for other risk factors (hazard ratio 1.24, 95 % CI 0.82 to 1.90). Conclusions: The incidence of major amputation in North Queensland has not reduced over time, indicating the need for better preventative treatments, particularly in Aboriginal and Torres Strait Islander people.