Hospital surgical volumes and mortality after coronary artery bypass grafting: using international comparisons to determine a safe threshold

Nils Gutacker, Karen Elizabeth Bloor, Richard Andrew Cookson, Christopher Gale, Alan Keith Maynard, Domenico Pagano, Jose Pomar, Enrique Bernal-Delgado, as part of the ECHO collaboration

Research output: Contribution to journalArticlepeer-review


Objective: To estimate a safe minimum hospital volume for hospitals performing coronary artery bypass graft (CABG) surgery. Data Source: Hospital data on all publicly funded CABG 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 CI: 4.0–6.4) in low-volume hospitals, and 2.1 percent (95 percent CI: 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 CABG volume and mortality in Europe, implying a “safe” threshold volume of 415 cases per year.

Original languageEnglish
Pages (from-to)863-878
Number of pages16
JournalHealth services research
Issue number2
Early online date16 May 2016
Publication statusPublished - 12 Mar 2017

Bibliographical note

© Health Research and Educational Trust. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details


  • Coronary artery bypass surgery
  • center-volume
  • international comparisons
  • mortality
  • Coronary Artery Bypass/mortality
  • Hospital Mortality
  • Humans
  • Middle Aged
  • England/epidemiology
  • Diagnosis-Related Groups
  • Male
  • Slovenia/epidemiology
  • Surgical Procedures, Operative/statistics & numerical data
  • Denmark/epidemiology
  • Surgery Department, Hospital/standards
  • Aged, 80 and over
  • Adult
  • Female
  • Aged
  • Portugal/epidemiology
  • Spain/epidemiology

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