National and State-Level Trends in Nontraumatic Lower-Extremity Amputation Among U.S. Medicare Beneficiaries With Diabetes, 2000-2017.

OBJECTIVE: Diabetes is a leading cause of nontraumatic lower-extremity amputation (NLEA) in the U.S. After a period of decline, some national U.S. data have shown that diabetes-related NLEAs 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 amputation [BKA], or above-the-knee amputation [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.

RESULTS: 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 < 0.001). However, from 2009 onward, NLEA rates increased to 4.8 (APC 1.2, P < 0.01). Trends were similar across most age, sex, and race/ethnic groups, but 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 U.S. states showed recent increases in NLEA, similar to national estimates.

CONCLUSIONS: This study of the U.S. 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 from increased attention to this strategy.