The STS Participant-Level, Multiprocedural Composite Measure for Adult Cardiac Surgery

Composite performance measures for the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database participants (typically hospital departments or practice groups) are currently available only for individual procedures. To assess overall participant performance, STS has developed a composite metric encompassing the most common adult cardiac procedures. Analyses included 1-year (July 1, 2018 to June 30, 2019) and 3-year (July 1, 2016 to June 30, 2019) time windows. Operations included isolated coronary artery bypass grafting (CABG), isolated aortic valve replacement (AVR), isolated mitral valve repair (MVr) or replacement (MVR), AVR + CABG, MVr or MVR + CABG, AVR + MVr or MVR, and AVR + (MVr or MVR) + CABG. The composite was estimated using Bayesian hierarchical models with risk-adjusted mortality and morbidity end points. Star ratings were based upon whether the 95% credible interval of a participant’s score was entirely lower than (1 star), overlapping (2 star), or higher than (3 star) the STS average composite score. The North American procedural mix in the 3-year study cohort was as follows: 448 569 CABG, 72 067 AVR, 35 708 MVr, 29 953 MVR, 45 254 AVR + CABG, 12 247 MVr + CABG, 10 118 MVR + CABG, 3743 AVR + MVr, 6846 AVR + MVR, and 3765 AVR + (MVr or MVR) + CABG. Mortality and morbidity weightings were similar for 1- and 3-year analyses (76% and 24% [3-year]), as were composite score distributions (median, 94.7%; interquartile range, 93.6% to 95.6% [3-year]). The 3-year time frame was selected for operational use because of higher model reliability (0.81 [0.78-0.83]) and better outlier discrimination (26%, 3 star; 16%, 1 star). Risk-adjusted outcomes for 1-, 2-, and 3-star programs were 4.3%, 3.0%, and 1.8% mortality and 18.4%, 13.4%, and 9.7% morbidity, respectively. The STS participant-level, multiprocedural composite measure provides comprehensive, highly reliable, overall quality assessment of adult cardiac surgery practices.