Volume 52 | Number 2 | April 2017

Abstract List

Hospital Surgical Volumes and Mortality after Coronary Artery Bypass Grafting: Using International Comparisons to Determine a Safe Threshold

Nils Gutacker Ph.D., Karen Bloor Ph.D., Richard Cookson Ph.D., Chris P. Gale Ph.D., Alan Maynard B.Phil., Hon D.Sc., Domenico Pagano M.D., José Pomar M.D., Ph.D., Enrique Bernal‐Delgado M.D., Ph.D.,


Objective

To estimate a safe minimum hospital volume for hospitals performing coronary artery bypass graft () surgery.


Data Source

Hospital data on all publicly funded in five European countries, 2007–2009 (106,149 patients).


Design

Hierarchical logistic regression models to estimate the relationship between hospital volume and mortality, allowing for case mix. Segmented regression analysis to estimate a threshold.


Findings

The 30‐day in‐hospital mortality rate was 3.0 percent overall, 5.2 percent (95 percent : 4.0–6.4) in low‐volume hospitals, and 2.1 percent (95 percent : 1.8–2.3) in high‐volume hospitals. There is a significant curvilinear relationship between volume and mortality, flatter above 415 cases per hospital per year.


Conclusions

There is a clear relationship between hospital volume and mortality in Europe, implying a “safe” threshold volume of 415 cases per year.