Racial disparities in the use of revascularization before leg amputation in Medicare patients

Abstract

Objective: Black patients with peripheral arterial disease undergo amputation at two to four times the rate of white patients. In order to determine whether differences in attempts at limb salvage might contribute to this disparity, we studied the limb care received prior to amputation by black patients compared with whites.

Methods: Using inpatient Medicare data for the years 2003 through 2006, we identified a retrospective sample of all beneficiaries who underwent major lower extremity amputation. "Limb salvage care" was defined as limb-related admissions and procedures that occurred during the 2 years prior to amputation. We used multiple logistic regression to compare rates of revascularization and other limb care received by black versus white amputees, adjusting for individual patient characteristics. We then controlled for hospital referral region in order to assess whether differences in care might be attributable to the geographic regions in which black and white patients received care. Finally, we examined the timing of revascularization relative to amputation for both races.

Results: Our sample included 24,600 black and 65,881 white amputees. Compared with whites, black amputees were more likely to be female and had lower socioeconomic status. Average age, rates of diabetes, and levels of comorbidity were similar between races. Black amputees were significantly less likely than whites to have undergone revascularization (23.6% vs 31.6%; P < .0001), any limb-related admission (39.6% vs 44.7%; P < .0001), toe amputation (12.9% vs 13.8%; P < .0005), or wound debridement (11.6% vs 14.2%; P < .0001) prior to amputation. After adjusting for differences in individual patient characteristics, black amputees remained significantly less likely than whites to undergo revascularization (odds ratios [OR], 0.72 [95% confidence interval, .68-.76]), limb-related admission (OR, 0.81 [0.78-0.84]), or wound debridement prior to amputation (OR, 0.80 [0.75-0.85]). Timing of revascularization relative to amputation was similar between races. Observed differences in care were shown to exist within hospital referral regions and were not accounted for by regional differences in where black and white patients received care.

Conclusion: Black patients are much less likely than whites to undergo attempts at limb salvage prior to amputation. Further studies should explore whether this disparity might be attributable to race-related differences in severity of arterial disease, patient preferences, or physician decision making.

Figure 1

Percentage of patients undergoing revascularization prior to amputation. * = P < .0001

Figure 2

Timing of revascularization: Proportion of revascularizations occurring within specific time intervals relative to amputation.

Figure 3

Timing of revascularization: Percentage of patients undergoing revascularization within specific time intervals prior to amputation. * = P < .0001

Figure 4

Percent of patients receiving other components of limb salvage care prior to amputation. Adm = limb related admission; Toe = toe amputation; Wnd = wound debridement. * = P < .0001, † = P < .0005