Explaining Racial Disparities in Outcomes After Cardiac Surgery: The Role of Hospital Quality

Study Questions:

What are the effects of hospital quality on racial disparities in mortality rates after coronary artery bypass graft (CABG) surgery?


The national Medicare database (2007-2008) was used to identify 173,925 patients undergoing CABG surgery in US hospitals. The primary measure of quality was the risk-adjusted mortality rate for each hospital. Logistic regression was used to determine the relationship between race and mortality rates, accounting for patient characteristics, socioeconomic status, and hospital quality.


Nonwhite patients had 33% higher risk-adjusted mortality rates after CABG surgery than white patients (odds ratio [OR], 1.33; 95% confidence interval [CI], 1.23-1.45). In hospitals treating the highest proportion of nonwhite patients (>17.7%), the mortality was 4.8% in nonwhite and 3.8% in white patients. When assessed independently, differences in hospital quality explained 35% of the observed disparity in mortality rates (OR, 1.22; 95% CI, 1.12-1.34). The authors were able to explain 53% of the observed disparity after adjusting for differences in socioeconomic status and hospital quality. However, even after these factors were taken into account, nonwhite patients had a 16% higher mortality (OR, 1.16; 95% CI, 1.05-1.27).


The authors concluded that hospital quality contributes significantly to racial disparities in outcomes after CABG surgery.


This study reported that compared with white patients, nonwhite patients have a significantly higher mortality rate after CABG surgery. Decreased access to high-quality hospitals explains a large proportion of the observed racial disparity in mortality rates. When analyzed independently, differential access to high-quality care accounts for 35% of the disparity between white and nonwhite patients. Future research needs to address geographic determinants of access to high-quality surgical care and the effects of social segregation and established referral patterns. With a better understanding of the barriers to high-quality care, policy makers may be able to design more effective programs to decrease health disparities. At the same time, efforts need to be made to improve quality of care in underperforming centers treating disproportionately high numbers of nonwhite patients.

Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Cardiac Surgery and Arrhythmias

Keywords: Racism, European Continental Ancestry Group, Thoracic Surgery, Coronary Artery Bypass, Cardiac Surgical Procedures, United States

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