Sex and Race Differences in the Utilization and Outcomes of Coronary Artery Bypass Grafting Among Medicare Beneficiaries, 1999–2014

BACKGROUND: With over a decade of directed efforts to reduce sex and racial differences in coronary artery bypass grafting (CABG) utilization, and post-CABG outcomes, we sought to evaluate how the use of CABG and its outcomes have evolved in different sex and racial subgroups. METHODS AND RESULTS: Using data on all fee-for-service Medicare beneficiaries undergoing CABG in the United States from 1999 to 2014, we examined differences by sex and race in calendar-year trends for CABG utilization and post-CABG outcomes (in-hospital, 30-day, and 1-year mortality and 30-day readmission). A total of 1 863 719 Medicare fee-for-service beneficiaries (33.6% women, 4.6% black) underwent CABG from 1999 to 2014, with a decrease from 611 to 245 CABG procedures per 100 000 person-years. Men compared with women and whites compared with blacks had higher CABG utilization, with declines in all subgroups. Higher post-CABG annual declines in mortality (95% confidence interval) were observed in women (in-hospital, -2.70% -2.97, -2.44; 30-day, -2.29% -2.54, -2.04; and 1-year mortality, -1.67% -1.88, -1.46) and blacks (in-hospital, -3.31% -4.02, -2.60; 30-day, -2.80% -3.49, -2.12; and 1-year mortality, -2.38% -2.92, -1.84), compared with men and whites, respectively. Mortality rates remained higher in women and blacks, but differences narrowed over time. Annual adjusted 30-day readmission rates remained unchanged for all patient groups. CONCLUSIONS: Women and black patients had persistently higher CABG mortality than men and white patients, respectively, despite greater declines over the time period. These findings indicate progress, but also the need for further progress.