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Risk stratification for open heart operations: comparison of centers regardless of the influence of the surgical team
P Pinna-Pintor1, M Bobbio, L Sandrelli
1Arturo Pinna Pintor Foundation-Torino, Italy.
Insights
The hospital, not the surgical team, significantly impacts open-heart surgery patient mortality. This study found that institutional differences, not surgeon skill, affected patient survival rates.
Area of Science:
- Cardiovascular Surgery
- Healthcare Quality Improvement
- Surgical Outcomes Research
Background:
- Previous comparisons of surgical outcomes focused on institutions or individual surgeons.
- A consistent surgical team operating in two different hospitals presented a unique opportunity to isolate institutional effects on patient mortality.
Purpose of the Study:
- To determine if the healthcare institution itself influences patient mortality in open-heart operations.
- To differentiate the impact of the surgical team versus the hospital environment on surgical outcomes.
Main Methods:
- Prospective data collection from 554 patients at institution A and 500 at institution B during the same period.
- All patients underwent surgery performed by the identical surgical, anesthesiology, and first assistant team in both institutions.
- Patient risk stratification using Parsonnet's model, with mortality adjusted via direct standardization.
Main Results:
- In-hospital mortality rates were 2.3% at institution A and 4.0% at institution B (not statistically significant).
- Standardized mortality ratios revealed significant differences: 3.6% for institution A versus 5.8% for institution B (p = 0.01).
- The statistically significant difference in standardized mortality ratios indicates a substantial institutional impact on patient outcomes.
Conclusions:
- Healthcare institutions play a significant role in patient mortality following open-heart surgery.
- The findings suggest that hospital-level factors, independent of surgical team expertise, can influence patient survival rates.
Background:
Risk-adjusted mortality was previously used to compare institutions as a whole or surgeons. Because the same surgical team is working in two different hospitals, the aim of our study was to assess whether the institution can make a difference in surgical mortality.
Methods:
Preoperative data of 554 patients in institution A and 500 in institution B were prospectively collected during the same period of time. All patients were operated on by the same surgeon with the same first assistant and anesthesiology staff in both institutions. Patient population was stratified according to Parsonnet's predictive model, in five risk groups, and mortality was adjusted by the direct standardization method.
Results:
At institution A it was observed that in-hospital mortality was 2.3% (95% confidence interval, 1.3% to 4.0%), and in institution B 4.0% (95% confidence interval, 2.5% to 6.1%). The difference between the two mortality rates (1.7%; 95% confidence interval, -0.5% to 3.8%) is not statistically significant (p = 0.16), nor is the difference within each class. The standardized mortality ratio was 3.6% (95% confidence interval, 2.7% to 4.8%) and 5.8% (95% confidence interval, 4.6% to 7.2%), respectively. The difference of 2.2% (95% confidence interval, 0.5% to 3.8%) is statistically significant (p = 0.01).
Conclusions:
The institution can affect mortality of patients undergoing open heart operations, regardless of the influence of the surgical team.