Explaining Racial Variation in Lower Extremity Amputation

HYPOTHESIS: Population-based hospital data indicate that African American patients undergo major lower extremity (LE) amputation 2 to 3 times more frequently than white patients. Some have attributed this to a lack of access to LE revascularization procedures by African American patients. To determine the likelihood that racial disparities in amputation rates are related to treatment choice, this study examines rates of primary amputation (major amputation without any previous attempt at revascularization) and repeat amputation. DESIGN AND SETTING: Two-step case-control study, reviewing experience at a large midwestern teaching hospital. First, administrative discharge data for all 1127 patients undergoing LE arterial bypass graft, angioplasty, or major amputation from January 1, 1995, to February 1, 2000, were used to analyze racial differences in the risk of admission for major amputation vs revascularization. Medical records were then reviewed for an approximate full sample of 60 African American major amputees and a random sample of 60 (two thirds of the total) white major amputees. Racial disparities in frequency of primary and repeat amputation were analyzed, controlling for age, sex, and diabetes mellitus status. OUTCOME MEASURES: Among all patients admitted for LE ischemia, outcome measures were the odds of amputation vs revascularization, and among a sample of African American and white amputees, the odds of primary vs repeat major amputation. RESULTS: Among all patients hospitalized for LE ischemia, African American patients were younger (P<.05), more often female (P<.01), and more likely to undergo major amputation (odds ratio, 1.68; P =.005). However, after adjusting for age, sex, and diabetes mellitus prevalence, the analysis revealed an equal likelihood of primary amputation among African Americans and whites. Repeat amputees were 2.5 times more likely to be African American than white (P =.04). CONCLUSION: The racial disparity at the study institution was primarily due to African American patients undergoing repeat major amputation at a significantly higher rate than whites.