Mandatory public reporting of cardiac surgery outcomes: The 2003 to 2014 Massachusetts experience.

Objectives: Beginning in 2002, all 14 Massachusetts nonfederal cardiac surgery programs submitted Society of Thoracic Surgeons (STS) National Database data to the Massachusetts Data Analysis Center for mandatory state-based analysis and reporting, and to STS for nationally benchmarked analyses. We sought to determine whether longitudinal prevalences and trends in risk factors and observed and expected mortality differed between Massachusetts and the nation.

Methods: We analyzed 2003 to 2014 expected (STS predicted risk of operative [in-hospital + 30-day] mortality), observed, and risk-standardized isolated coronary artery bypass graft mortality using Massachusetts STS data (N = 39,400 cases) and national STS data (N = 1,815,234 cases). Analyses included percentage shares of total Massachusetts coronary artery bypass graft volume and expected mortality rates of 2 hospitals before and after outlier designation.

Results: Massachusetts patients had significantly higher odds of diabetes, peripheral vascular disease, low ejection fraction, and age ≥75 years relative to national data and lower odds of shock (odds ratio, 0.66; 99% confidence interval, 0.53-0.83), emergency (odds ratio, 0.57, 99% confidence interval, 0.52-0.61), reoperation, chronic lung disease, dialysis, obesity, and female sex. STS predicted risk of operative [in-hospital + 30-day] mortality for Massachusetts patients was higher than national rates during 2003 to 2007 (P < .001) and no different during 2008 to 2014 (P = .135). Adjusting for STS predicted risk of operative [in-hospital + 30-day] mortality, Massachusetts patients had significantly lower odds (odds ratio, 0.79; 99% confidence interval, 0.66-0.96) of 30-day mortality relative to national data. Outlier programs experienced inconsistent, transient influences on expected mortality and their percentage shares of Massachusetts coronary artery bypass graft cases.

Conclusions: During 12 years of mandatory public reporting, Massachusetts risk-standardized coronary artery bypass graft mortality was consistently and significantly lower than national rates, expected rates were comparable or higher, and evidence for risk aversion was conflicting and inconclusive.