Lower-extremity amputation varies significantly by region

While lower-extremity (LE) amputation rates decreased significantly among patients with peripheral artery disease (PAD) from 2000 to 2008, there remains significant patient and geographic variation in amputation rates across the U.S., according to a study of Medicare patients published Nov. 20 in the Journal of the American College of Cardiology.

LE PAD is a prevalent disorder that affects approximately 8 million Americans (J Am Coll Cardiol 2006;47:1239-1312). In its end stage, patients with severe PAD can require LE amputation, which is associated with significant morbidity, mortality and healthcare costs. They also wrote that “treatment of PAD often differs regionally, and it remains unclear whether geographic variation may further contribute to the risk of LE amputation.”

Consequently, W. Schuyler Jones, MD, of Duke University Medical Center in Durham, N.C., and colleagues performed an analysis of U.S. Medicare data to provide a more contemporary report of national temporal and geographic trends in amputation, with three goals:

1. To characterize temporal trends in LE amputation during the study period;
2. To examine patient factors that were associated with LE amputation; and
3. To determine whether there was geographic variation in LE amputation across the U.S.

Using data from the Centers for Medicare & Medicaid Services (CMS) from Jan. 1, 2000, to Dec. 31, 2008, the researchers examined national patterns of LE amputation among patients aged 65 years or more with PAD. They also used a multivariable logistic regression to adjust regional results for other patient demographic and clinical factors.

Among the more than 2.73 million older patients with identified PAD, the overall rate of LE amputation decreased from 7,258 per 100,000 patients with PAD to 5,790 per 100,000. Overall, a total of 186,338 patients (6.8 percent of the overall hospitalized population with PAD) underwent LE amputation during the study period.

Among beneficiaries who underwent major LE amputation, approximately 65 percent were 75 years old or older, approximately 50 percent were men and 25 percent were black. Patients with PAD who underwent amputation were more likely to be black (28.1 vs. 9.5 percent), to have diabetes mellitus (60.3 vs. 35.7 percent), and to have renal disease (29.5 vs. 15.5 percent) when compared with patients with PAD who did not undergo an amputation. Thus, the study authors synopsized that the male sex, black race, diabetes mellitus and renal disease were all independent predictors of LE amputation.

Jones et al also reported there was “significant geographic variation” in the rate of LE amputation from 8,400 amputations per 100,000 patients with PAD in the East South Central region to 5,500 amputations per 100,000 patients with PAD in the Mountain region.

Based on their findings from this large, observational study, the authors suggested that future studies should aim to determine the factors associated with the observed reduction in amputations and geographic variation. Also, they noted that “the current study demonstrates the critical need for education programs for clinicians and patients that will focus on best practices for the prevention and treatment of PAD in patients at risk for LE amputation nationwide.”