The effect of risk and race on lower extremity amputations among Medicare diabetic patients

Objective: The effect of national quality initiatives aiming at limiting lower extremity amputations in diabetic patients remains uncertain. We therefore explored trends in amputation among Medicare diabetic patients with a focus on those at highest risk. Methods: The Diabetes Analytical File, an enhanced sample of all diabetic patients from the Medicare 5% sample, was used to study the national incidence of amputation in diabetic patients. Within a cohort of similar to 5 million diabetic patients between 1999 and 2006, we compared the incidence of amputation in high-risk (end-stage renal disease or more than three comorbidities) and low-risk groups and by race. Results: Between 1999 and 2006, 23,976 amputations were performed, comprising 11,558 in high-risk and 12,418 in low-risk patients. The amputation rate declined over time from 4.8/1000 in 1999 to 4.4/1000 in 2006 (P < .001). High-risk patients represented a growing proportion of all amputations (33% in 1999, 50% in 2006; P < .001) despite representing 4% of diabetic patients in 1999 and 10% in 2006 (P < .001). The incidence of amputation was 29.6/1000 in the high-risk group vs 2.7/1000 in low-risk patients (P < .001). African Americans had higher rates of amputation in high-risk and low-risk groups. Conclusions: High-risk patients represent a minority of Medicare diabetic patients but account for 50% of all amputations, and this effect is magnified in African Americans. Future quality improvement efforts should focus on high-risk patients and African Americans. (J Vasc Surg 2012;56:1663-8.)