National and State-Level Trends in Non-Traumatic Lower Extremity Amputation Among U.S. Medicare Beneficiaries With Diabetes, 2000-2017
Diabetes is a leading cause of non-traumatic lower extremity amputation (NLEA) in the United States. After a period of decline, some national US data show that diabetes-related NLEA have recently increased, particularly among young and middle-aged adults. However, the trend for older adults is less clear.
Research Design and Methods
To examine NLEA trends among older adults with diabetes (≥67 years), we used 100% Medicare claims for beneficiaries enrolled in Parts A and B, also known as Fee for Service (FFS). NLEA was defined as the highest-level amputation per patient per calendar year. Annual NLEA rates were estimated from 2000 to 2017 and stratified by age group, sex, race/ethnicity, NLEA level (toe, foot, below the knee (BKA), above the knee (AKA)), and state. All rates were age and sex standardized to the 2000 Medicare population. Trends over time were assessed using Joinpoint regression and annual percent change (APC) reported.
NLEA rates (per 1,000 people with diabetes) decreased by half from 8.5 in 2000 to 4.4 in 2009 (APC -7.9, p-value<0.001). However, from 2009 onwards NLEA rates increased to 4.8 (APC 1.2, p-value<0.01). Trends were similar across most age, sex and race/ethnic groups, however absolute rates were highest in the oldest age groups, blacks and men. By NLEA type, overall increases were driven by increases in rates of toe and foot NLEAs while BKA and AKA continued to decline. The majority of US states showed recent increases in NLEA, similar to national estimates.
This study of the US Medicare FFS population shows that recent increases in diabetes-related NLEAs are also occurring in older populations but at a less severe rate than among younger adults (<65 years) in the general population. Preventive foot care has been shown to reduce rates of NLEA among adults with diabetes, and the findings of the study suggest that those with diabetes – across the age spectrum – could benefit by increased attention to this strategy.