Disparities in surgical 30-day readmission rates for Medicare beneficiaries by race and site of care.

OBJECTIVE: To determine whether black patients have higher odds of readmission than white patients after major surgery, and to ascertain whether these disparities are related to where black patients receive care.

BACKGROUND: Racial disparities are known to exist for many aspects of surgical care. However, it is unknown if disparities exist in readmissions after a surgical procedure, an area which is becoming a prime focus for clinical leaders and policymakers.

METHODS: Using national Medicare data from 2007 to 2010, we examined 30-day readmissions for patients undergoing coronary artery bypass grafting, pulmonary lobectomy, endovascular abdominal aortic aneurysm repair, open abdominal aortic aneurysm repair, colectomy, and hip replacement. The main outcome measure was risk-adjusted odds of all-cause 30-day readmission. We used multivariate logistic regression to determine if black patients had higher readmission rates than white patients, and if so, whether this effect was mediated by the hospitals at which patients received care, or by poverty.

RESULTS: Black patients had higher readmission rates than white patients (14.8% vs 12.8%, odds ratio [OR] 1.19; 95% confidence interval [CI], 1.16-1.22; P < 0.001). Patients undergoing major surgery at minority-serving hospitals also had higher readmission rates (14.3% vs 12.8%, OR 1.14, 95% CI 1.09-1.19; P < 0.001). In multivariate analyses, black patients at minority-serving hospitals had the highest overall odds of readmissions (OR 1.34). White patients at minority-serving hospitals (OR 1.15) and black patients at non-minority-serving hospitals (OR 1.20) also had higher odds of readmission than the reference group of white patients at non-minority-serving hospitals. Racial disparities were mediated in part by poverty.

CONCLUSIONS: Among Medicare beneficiaries, black patients were more likely to be readmitted after hospitalization for surgical procedures. Since racial disparities in readmission rates are mediated both by patients' race and the hospital at which care is delivered, efforts at reducing disparities should focus not only on race-based measures but also on improving outcomes of care at minority-serving hospitals.