Do Differences in Hospital and Surgeon Quality Explain Racial Disparities in Lower-Extremity Vascular Amputations?

Abstract

To understand whether racial disparities in surgery for lower-extremity arterial disease are minimized by high-quality providers, or instead, differential treatment of otherwise similar patients pervades all settings. Black patients are substantially more likely than whites to undergo amputation rather than revascularization for lower-extremity arterial disease. Because their care is disproportionately concentrated among a small share of providers, some have attributed such disparities to the quality and capacity of these sites. We evaluated all 86,865 white or black fee-for-service Medicare beneficiaries 65 and older who underwent major lower-extremity vascular procedures. Using generalized linear mixed models with random effects, we computed risk-adjusted odds of amputation by race overall, and after serial substratification by salient patient and provider characteristics. Blacks were far more likely to undergo amputation (45% vs. 20%). Their procedures were performed more often by nonspecialists (41% vs. 27%; P < 0.001), in low-volume hospitals (40% vs. 32%; P < 0.001), with high amputation rates (53% vs. 29%; P < 0.001). Controlling for differences in comorbidity, disease severity, and surgeon and hospital performance, blacks' odds of amputation remained 1.7 times greater (95% confidence interval: 1.6-1.9). Even among highest-performing providers-vascular specialists in high-volume, urban teaching hospitals with angioplasty facilities-racial gaps persisted (risk-adjusted amputation rates: 7% for blacks vs. 4% for whites, P < 0.001; odds ratio: 1.8, 95% confidence interval: 1.5-2.1). Black patients with critical limb ischemia face significantly higher risk of major amputation, even when treated by providers with highest likelihoods of revascularization. Increased referral to high-performing providers might increase limb-preservation, but cannot eliminate disparities until equitable treatment can be ensured in all settings.