Association of Hospital and Physician Characteristics and Care Processes with Racial Disparities in Procedural Outcomes Among Contemporary Patients Undergoing Coronary Artery Bypass Grafting Surgery
Background—Prior studies have reported that blacks undergoing coronary artery bypass surgery (CABG) had worse outcomes than white patients, even after accounting for patient factors. The degree to which clinician-, hospital- and care-factors account for these outcome differences remains unclear.
Methods and Results—We evaluated procedural outcomes in 11697 blacks and 136,362 whites undergoing isolated CABG at 663 STS Database participating sites (1/1/2010-6/30/2011) adjusted for patients' clinical and socioeconomic features, hospital and surgeon effects and care processes (internal mammary artery [IMA] graft and perioperative medications use). Relative to whites, blacks undergoing CABG were younger, yet had higher comorbidities and more adverse presenting features. Blacks were also more likely to be treated at hospitals with higher risk-adjusted mortality. The use of IMA was marginally lower in blacks than whites (93.3% vs. 92.2%, p<0.0001). Unadjusted mortality and major morbidity rates were higher in blacks than whites (1.8% vs. 2.5%, p<0.0001) and (13.6% vs. 19.4%, p <0.0001), respectively. These racial differences in outcomes narrowed but still persisted after adjusting for surgeon, hospital and care processes in addition to patient and socioeconomic factors (OR 1.17 [1.00-1.36] and OR 1.26 [1.19-1.34], respectively).
Conclusions—The risks of procedural mortality and morbidity after CABG were higher among black compared with white patients. These differences were in part accounted for by patient comorbidities, socioeconomic status, as well as surgeon, hospital, and care factors as suggested by reduction in the strength of the race-outcomes association. However, black race remained an independent predictor of outcomes even after accounting for these differences.
- Received February 10, 2015.
- Revision received October 20, 2015.
- Accepted October 23, 2015.