Lower extremity nontraumatic amputation among veterans with peripheral arterial disease: is race an independent factor?

Abstract

To determine if race/ethnicity is independently associated with an increased risk for nontraumatic lower extremity amputation versus lower extremity bypass revascularization among patients with peripheral arterial disease (PAD). Data were analyzed from the National VA Surgical Quality Improvement Program (NSQIP) and from the Veterans Affairs Patient Treatment File (PTF). Race/ethnicity was defined as non-Hispanic white, black, or Hispanic. Variables that were univariately associated (P < or = 0.05) with the outcome of amputation were placed into a multiple logistic regression model to determine independent predictors for the dependent variable, lower extremity amputation versus lower extremity bypass revascularization. Three thousand eighty-five lower extremity amputations and 8409 lower extremity bypass operations were identified. Among all cases included, there were 416 Hispanic patients (3.6%), 2337 black patients (20.3%), and 8741 non-Hispanic white patients (76.1%). Among all variables within the model, Hispanic and black race were each associated with a greater risk for amputation than a history of rest pain/gangrene (Hispanic race 1.4, 95% CI 1.1, 1.9; black race 1.5, 95% CI 1.4, 1.7; rest pain/gangrene 1.1, 95% CI 1.0, 1.3). The final model had a c statistic of 0.83. Hispanic race and black race were independent risk factors for lower extremity amputation in patients with PAD. Although the burden of certain atherosclerotic risk factors (eg, diabetes and hypertension) is higher in minority patients, the impact of this burden does not account for the increased risk for the outcome of lower extremity amputation in these two populations. Further research is needed to better understand the reason(s) why race/ethnicity is independently associated with poor outcomes in PAD.