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

Health Serv Res. 2017 Apr;52(2):863-878. doi: 10.1111/1475-6773.12508. Epub 2016 May 16.

Abstract

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.

Keywords: Coronary artery bypass surgery; center-volume; international comparisons; mortality.

Publication types

  • Comparative Study

MeSH terms

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