Temporal trends in initial and recurrent lower extremity amputations in people with and without diabetes in Western Australia from 2000 to 2010

Abstract

AimsTo examine temporal trends in lower extremity amputations in people with type 1 diabetes, type 2 diabetes and cardiovascular disease (CVD) without diabetes in Western Australia (WA) from 2000 to 2010. MethodsWe used linked health data to identify all non-traumatic lower extremity amputations in adults aged ≥20years with diabetes and/or CVD from 2000 to 2010 in WA. Annual age- and sex-standardised rates of total, initial and recurrent amputations, stratified by major and minor status, were calculated for type 1 and type 2 diabetes, and CVD without diabetes, from the at-risk population for each group. Age- and sex-adjusted trends were estimated from Poisson regression models. Results5891 lower extremity amputations were identified. Peripheral vascular disease (71%), hypertension (70%) and chronic kidney disease (60%) were highly prevalent. Average annual rates of total amputations were 724, 564 and 66 per 100,000 person-years in type 1, type 2 diabetes and CVD without diabetes respectively. Rates of initial amputations fell significantly by 2.4%/year (95% CI −3.5, −1.4) in type 2 diabetes, with similar declines for type 1 diabetes and CVD without diabetes (interaction p=0.96), driven by large falls in major amputations. There was limited improvement in recurrence rates overall, with recurrent minor amputations increasing significantly in type 2 diabetes (+3.5%/year, 95% CI +1.3%, +5.7%). ConclusionLower extremity amputation rates have declined at a population level in people with diabetes and CVD without diabetes, suggesting improvements in prevention and management for this high-risk patient group, however limited declines in recurrent amputations requires further investigation.