Coronary Artery Bypass Surgery: The Relationship Between Inhospital Mortality Rate and Surgical Volume After Controlling For Clinical Risk Factors

This study uses a new database containing clinical risk factors for cardiac surgery to investigate the relationship between surgical volume (hospital and surgeon) and inhospital mortality rate for all patients receiving coronary artery bypass surgery in New York State in 1989. Also, hospitals with significantly higher and lower mortality rates than expected on the basis of patient preoperative risk factors are identified. The results demonstrate that both annual surgeon volume and annual hospital volume are significantly (inversely) related to mortality rate. The 36% of all coronary bypass operations performed in hospitals with annual bypass volumes of 700 or more by surgeons with annual bypass volumes of 180 or more had a risk-adjusted mortality rate of 2.67% in comparison to a risk-adjusted mortality rate of 4.29% for other bypass operations. Furthermore, low surgical volumes were a major contributor to the outlier status of four of the five hospitals with significantly higher mortality rates than expected.

[1]  Determinants of operative mortality for patients undergoing aortic valve replacement. Discriminant analysis of 1,479 operations. , 1985 .

[2]  D. Pilcher,et al.  Treatment of abdominal aortic aneurysm in an entire state over 7 1/2 years. , 1980, American journal of surgery.

[3]  G. Dorros,et al.  Coronary artery bypass surgery in patients over age 70 years: Report from the milwaukee cardiovascular data registry , 1987, Clinical cardiology.

[4]  F. Sloan,et al.  In-hospital mortality of surgical patients: is there an empiric basis for standard setting? , 1986, Surgery.

[5]  D. Hosmer,et al.  Applied Logistic Regression , 1991 .

[6]  H. Horst,et al.  The relationship of scoring systems and mortality in the surgical intensive care unit. , 1987, The American surgeon.

[7]  F. Hellinger,et al.  Heart disease and hospital deaths: an empirical study. , 1987, Health services research.

[8]  H S Luft,et al.  Effects of Surgeon Volume and Hospital Volume on Quality of Care in Hospitals , 1987, Medical care.

[9]  A. Flood,et al.  Does Practice Make Perfect?: Part II: The Relation Between Volume and and Outcomes and Other Hospital Characteristics , 1984, Medical care.

[10]  H. Luft,et al.  The volume-outcome relationship: practice-makes-perfect or selective-referral patterns? , 1987, Health services research.

[11]  H. Luft.  The Relation Between Surgical Volume and Mortality: An Exploration of Causal Factors and Alternative Models , 1980, Medical care.

[12]  W. Knaus,et al.  APACHE II: a severity of disease classification system. , 1985 .

[13]  E. Blackstone.  Analysis of death (survival analysis) and other time-related events , 1986 .

[14]  F J Hellinger,et al.  Physician and Hospital Factors Associated With Mortality of Surgical Patients , 1986, Medical care.

[15]  S. Ellis,et al.  In-hospital cardiac mortality after acute closure after coronary angioplasty: analysis of risk factors from 8,207 procedures. , 1988, Journal of the American College of Cardiology.

[16]  S. Shortell,et al.  Hospital Medical Staff Organization and Quality of Care: Results for Myocardial Infarction and Appendectomy , 1981, Medical care.

[17]  F. Loop,et al.  Mortality and results after cardiac surgery in patients with end-stage renal disease. , 1988, Cleveland Clinic journal of medicine.

[18]  A. Bernstein,et al.  A method of uniform stratification of risk for evaluating the results of surgery in acquired adult heart disease. , 1989, Circulation.

[19]  M A Hlatky,et al.  Comparison of predictions based on observational data with the results of randomized controlled clinical trials of coronary artery bypass surgery. , 1988, Journal of the American College of Cardiology.

[20]  Edward L. Hannan,et al.  Investigation of the Relationship Between Volume and Mortality for Surgical Procedures Performed in New York State Hospitals , 1989 .

[21]  P. B. Kelly,et al.  Preoperative risk assessment in cardiac surgery: comparison of predicted and observed results. , 1987, The Annals of thoracic surgery.

[22]  W. Knaus,et al.  An evaluation of outcome from intensive care in major medical centers. , 1986, Annals of internal medicine.

[23]  N. Roos,et al.  Centralization, Certification, and Monitoring: Readmissions and Complications After Surgery , 1986, Medical care.

[24]  J. Wright,et al.  Multivariate discriminant analysis of risk factors for operative mortality following isolated coronary artery bypass graft. Loyola University Medical Center experience, 1970 to 1984. , 1987, Chest.

[25]  R. A. Johnson,et al.  Prognostic value of a coronary artery jeopardy score. , 1985, Journal of the American College of Cardiology.

[26]  M. Freeland,et al.  Selective contracting for hospital care based on volume, quality, and price: prospects, problems, and unanswered questions. , 1987, Journal of health politics, policy and law.

[27]  D. K. Williams,et al.  Assessing hospital-associated deaths from discharge data. The role of length of stay and comorbidities. , 1988, JAMA.

[28]  E. Blackstone,et al.  Death and other time-related events after valve replacement. , 1985, Circulation.

[29]  L. Mickleborough,et al.  Increased risk of urgent revascularization. , 1987, Journal of Thoracic and Cardiovascular Surgery.

[30]  R. Wenzel,et al.  Relation between surgical volume and incidence of postoperative wound infection. , 1981, The New England journal of medicine.

[31]  Harold S. Luft,et al.  Association of volume with outcome of coronary artery bypass graft surgery —scheduled vs nonscheduled operations , 1987, JAMA.

[32]  T. Preston.  Assessment of Coronary Bypass Surgery and Percutaneous Transluminal Coronary Angioplasty , 1989, International Journal of Technology Assessment in Health Care.

[33]  H. Luft,et al.  Hospital Volume and Patient Outcomes: The Case of Hip Fracture Patients , 1988, Medical care.

[34]  P. Sergeant,et al.  Is the outcome of coronary artery bypass graft surgery predictable in patients with severe ventricular function impairment? , 1986, The Journal of cardiovascular surgery.

[35]  A. Flood,et al.  Does Practice Make Perfect?: Part I: The Relation Between Hospital Volume and Outcomes for Selected Diagnostic Categories , 1984, Medical care.

[36]  H S Luft,et al.  Selecting Categories of Patients for Regionalization: Implications of the Relationship Between Volume and Outcome , 1986, Medical care.

[37]  F. Harrell,et al.  Predicting outcome in coronary disease. Statistical models versus expert clinicians. , 1986, The American journal of medicine.