Impact of diabetes on long-term mortality following major lower limb amputation: A population-based cohort study in Wales

Abstract

Background

Major lower limb amputation is associated with high morbidity and mortality, particularly among patients with diabetes. Previous studies suggest variable mortality rates, but none have investigated the impact of diabetes in Wales.

Methods

A population-based cohort study was conducted using anonymised data from the Secure Anonymised Information Linkage Databank. Survival from all incident major amputations in persons ≥ 18 years from 2006 to 2013 in Wales was assessed over 5-year follow-up. Kaplan-Meier survival curves and Cox regression models, stratified by amputation level, were used to examine the time-dependent effect of diabetes on mortality while adjusting for confounding factors.

Results

2542 individuals underwent major amputation, 48.4 % had diabetes. Mortality at 30 days was 9.2 % and 61.9 % within 5 years. Patients with diabetes had higher 5-year mortality (67.0 %) compared to those without diabetes (57.1 %). Diabetes was associated with an increased risk of long-term mortality (hazard ratio 1.62, p < 0.001), but a reduced risk of death in the first 30 days post-amputation. A history of peripheral vascular disease and above-knee amputation were strong predictors of mortality.

Conclusion

Time-stratified analysis demonstrates lower short-term but higher long-term mortality risk for persons with diabetes following major amputation. Further research is required to explore interventions aimed at improving survival.