Quantifying the incidence of lower limb amputation in people with and without diabetes in Wales between 2008–2018

Background

There is variance in the incidence of lower extremity amputation across and within countries including within the UK. National data shows up to a fourfold variance in the amputation rate throughout the regions of England and differences in amputation incidence have been reported in Scotland and Ireland. Lower extremity amputation rate has yet to be documented within Wales. The aim of this cohort study was to examine trends in diabetes and non-diabetes related lower extremity amputation incidence within the Welsh population and to examine the influence of diabetes on the relative risk of amputation.

Materials and Methods

All first-time amputations between 2008-2018 were extracted from SAIL, a repository of all routine medical data of residents of Wales. People with diabetes were identified using an algorithm utilising data from several clinical and non-clinical sources. Crude and direct age and sex adjusted incidences were estimated over time.

Results

Over the period 3505 major amputations and 4335 minor amputations occurred. The diabetes population greater than 17 years of age increased by 29.4% from 143,595 in 2008 to 206,818 in 2018. There was a statistically significant rate reduction in major amputation in both populations. In the diabetes population the number of major amputations reduced from 6.9 [5.5–8.5]/10 000 person years (PY) in 2008 to 4.9 [5.4–6.2]/10 000 PY in 2018. However, for major amputation, the risk of incident amputation in people with diabetes was 7.3 fold higher [7.1–7.5] than those without diabetes. The relative risk of minor amputation for those with diabetes was higher at 11.9 [11.8 –1.01]. There was no reduction in this risk over the period.

Conclusion

This study found that rates of major amputation decreased over the study period but the risk of amputation for persons with diabetes remained substantial. As the population with diabetes increases so do crude rates of amputation, providing a substantial financial and societal cost to the Welsh Population.