Peripheral arterial testing before lower extremity amputation among Medicare beneficiaries, 2000 to 2010

Abstract

Background: Despite mild reductions in rates of lower extremity amputation over the past decade, few data exist on the use of arterial testing in patients before amputation.

Methods and results: Using Medicare claims from 2000 through 2010, we examined rates of preamputation arterial testing between 0 to 12 and 0 to 24 months before amputation. We used multivariable, modified Poisson regression models to identify patient and clinical predictors of preamputation arterial testing. The main outcome measures were rates of preamputation arterial testing. Among 17 463 patients undergoing nontraumatic amputation, 68.4% underwent some type of arterial testing. Of these patients, 47.5% underwent ankle-brachial index measurement, 38.7% duplex ultrasound, 31.1% invasive angiography, 6.7% computed tomographic angiography, and 5.6% magnetic resonance angiography. Temporal analysis revealed an increase in testing from 65.7% in 2002 to 69.2% in 2010 (P<0.001). The use of preamputation arterial testing varied significantly by location of amputation and was lowest for foot amputation (62.5%), followed by above-knee amputation (69.0%) and below-knee amputation (76.7%; P<0.001). After multivariable adjustment, older age, male sex, black race, renal disease, diabetes mellitus, known peripheral arterial disease, evaluation by a vascular specialist, and living in the East North Central region were associated with greater rates of preamputation arterial testing.

Conclusions: Rates of evaluation for peripheral arterial disease before amputation were low, and testing varied by patient, provider, and regional characteristics.

Keywords: amputation; ankle-brachial index; diagnostic techniques, cardiovascular; peripheral arterial disease.