Variation in Amputation Risk for Black Patients: Uncovering Potential Sources of Bias and Opportunities for Intervention.

Background: Differences in amputation rates for limb ischemia between white and black patients have been extensively studied. Our goal was to determine whether biases in provider decision-making contribute to the disparity. We hypothesized that the magnitude of the disparity is affected by surgeon and hospital factors.

Study Design: Analysis of the New York Statewide Planning and Research Cooperative System database was performed for 1999 to 2014. Black and white patients with ICD9 codes for peripheral vascular disease, who received either an amputation or salvage procedure, were included. The primary endpoint was treatment choice.

Results: We analyzed 215,480 inpatient admissions. The overall amputation rate was 38.0%, and blacks were significantly more likely to receive amputations than whites on unadjusted (42.6% vs 28.6%, p < 0.001), and multivariable analyses (odds ratio [OR] 1.45, 95% CI 1.31 to 1.60, p < 0.001). This difference was more pronounced among high total vascular volume surgeons (OR 1.74, 95% CI 1.50 to 2.00, p < 0.001), but not among those with low total vascular volume (OR 1.06, 95% CI 0.90 to 1.24, p = 0.49); high volume hospitals (OR 1.57, 95% CI 1.39 to 1.78, p < 0.001), but not among those with low amputation volume (OR 0.96, 95% CI 0.73 to 1.27, p < 0.80); and surgeons who treat fewer black patients (OR 1.58, 95% CI 1.44 to 1.73, p < 0.001) vs surgeons who see more black patients (OR 1.43, 95% CI 1.30 to 1.57, p < 0.0.001).

Conclusions: Black patients are significantly more likely to receive an amputation than a salvage procedure when presenting with significant peripheral vascular diseases. High procedural volume does not seem to reduce unequal treatment; diversity of surgeon practice does.