Statistics Papers

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Technical Report

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Medical Care





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BACKGROUND: Racial disparities in general surgical outcomes are known to exist but not well understood.

OBJECTIVES: To determine if black-white disparities in general surgery mortality for Medicare patients are attributable to poorer health status among blacks on admission or differences in the quality of care provided by the admitting hospitals.

RESEARCH DESIGN: Matched cohort study using Tapered Multivariate Matching.

SUBJECTS: All black elderly Medicare general surgical patients (N=18,861) and white-matched controls within the same 6 states or within the same 838 hospitals.

MEASURES: Thirty-day mortality (primary); others include in-hospital mortality, failure-to-rescue, complications, length of stay, and readmissions.

RESULTS: Matching on age, sex, year, state, and the exact same procedure, blacks had higher 30-day mortality (4.0% vs. 3.5%, P<0.01), in-hospital mortality (3.9% vs. 2.9%, P<0.0001), in-hospital complications (64.3% vs. 56.8% P<0.0001), and failure-to-rescue rates (6.1% vs. 5.1% P<0.001), longer length of stay (7.2 vs. 5.8 d, P<0.0001), and more 30-day readmissions (15.0% vs. 12.5%, P<0.0001). Adding preoperative risk factors to the above match, there was no significant difference in mortality or failure-to-rescue, and all other outcome differences were small. Blacks matched to whites in the same hospital displayed no significant differences in mortality, failure-to-rescue, or readmissions.

CONCLUSIONS: Black and white Medicare patients undergoing the same procedures with closely matched risk factors displayed similar mortality, suggesting that racial disparities in general surgical mortality are not because of differences in hospital quality. To reduce the observed disparities in surgical outcomes, the poorer health of blacks on presentation for surgery must be addressed.

Copyright/Permission Statement

This is a non-final version of an article published in final form in (Silber, J.H., Rosenbaum, P.R., Kelz, R.R., Gaskin, D.J., Ludwig, J.M., Ross, R.N., Niknam, B.A., Hill, A., Wang, M., Even-Shoshan, O., & Fleisher, L.A. (2015). Examining Causes of Racial Disparities in General Surgical Mortality: Hospital Quality Versus Patient Risk. Medical Care 53, no. 7: pp. 619-629.


racial disparities, multivariate matching, general surgery



Date Posted: 25 October 2018

This document has been peer reviewed.