Explaining racial disparities in outcomes after cardiac surgery: the role of hospital quality

JAMA Surg. 2014 Mar;149(3):223-7. doi: 10.1001/jamasurg.2013.4041.


Importance: Racial disparities in mortality rates after coronary artery bypass graft (CABG) surgery are well established. We have yet to fully understand how care at high-mortality, low-quality hospitals contributes to racial disparities in surgical outcomes.

Objective: To determine the effects of hospital quality on racial disparities in mortality rates after CABG surgery.

Design, setting, and participants: The national Medicare database (2007-2008) was used to identify 173,925 patients undergoing CABG surgery in US hospitals.

Main outcomes and measures: Our 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.

Results: Nonwhite patients had 33% higher risk-adjusted mortality rates after CABG surgery than white patients (odds ratio [OR], 1.33; 95% 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). We 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).

Conclusions and relevance: Hospital quality contributes significantly to racial disparities in outcomes after CABG surgery. However, a significant fraction of this racial disparity remains unexplained. Efforts to decrease racial disparities in health care should focus on underperforming centers of care treating disproportionately high numbers of nonwhite patients.

MeSH terms

  • Aged
  • Black or African American / statistics & numerical data
  • Coronary Artery Bypass / mortality*
  • Coronary Disease / ethnology
  • Coronary Disease / surgery
  • Female
  • Health Status Disparities*
  • Hispanic or Latino / statistics & numerical data
  • Hospital Mortality / ethnology*
  • Hospitals / standards*
  • Humans
  • Logistic Models
  • Male
  • Medicare / statistics & numerical data
  • Odds Ratio
  • Outcome Assessment, Health Care*
  • Quality Indicators, Health Care* / statistics & numerical data
  • Quality of Health Care
  • Racial Groups / statistics & numerical data*
  • Social Class
  • United States / epidemiology
  • White People / statistics & numerical data