Comparative Analysis of Vizient and The Society of Thoracic Surgeons (STS) Performance Ratings in Cardiac Surgery: A Qualitative Review
Related Experiment Video
Updated: Aug 26, 2026
Technique and Patient Selection Criteria of Right Anterior Mini-Thoracotomy for Minimal Access Aortic Valve Replacement
Published on: March 26, 2018
Lucy Nam1, Xiu Liu2, Ruby Singh1
1Division of Cardiac Surgery, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts.
Background:
The Society of Thoracic Surgeons (STS) and Vizient each produce rating systems for cardiac surgery performance. At our institution, during a similar time frame and for nominally similar cohorts, STS ratings indicated exemplary performance, whereas Vizient suggested worse than expected performance. We hypothesized that these discordant quality signals were driven by methodologic differences in how each platform defines cohorts, captures data, adjusts risk, and measures outcomes.
Methods:
We conducted a single-institution, 12-month retrospective comparison of procedures categorized as isolated coronary artery bypass grafting (CABG) by STS or Vizient. We compared data sources, patient cohort definitions, observation periods, risk modeling, and outcome definitions, and performed medical record review of cases unique to either database.
Results:
STS identified 414 and Vizient 407 patients in their isolated CABG cohorts. Of these, 398 patients were shared, whereas 16 were unique to STS and 9 to Vizient. STS and Vizient recorded discrepant mortality counts (9 vs 8 deaths, respectively). Medical record reviews revealed discordant operative procedure classifications and inconsistent capture of perioperative events between systems. STS relies on audited clinical registry data, clinically defined patient cohorts and risk factors, peer reviewed risk models and measures, and multiyear rolling data windows. Vizient uses administrative claims data and associated risk-adjustment variables and outcomes, proprietary methodologies, and shorter reporting cycles.
Conclusions:
Discordant assessments of cardiac surgery performance by STS and Vizient quality ratings reflect multiple methodologic differences. Understanding these differences is essential for assessing the credibility of these 2 performance rating systems, reconciling conflicting reports, educating hospital leadership and the public, and guiding evidence-based quality improvement.
