Skip to main content
PMC home page
CMAJ : Canadian Medical Association Journal logoLink to CMAJ : Canadian Medical Association Journal
. 1998 Oct 20;159(8):926–930.

Coronary artery bypass grafting in Canada: hospital mortality rates, 1992-1995

W A Ghali 1, H Quan 1, R Brant 1
PMCID: PMC1229737  PMID: 9834717

Abstract

BACKGROUND: Rates of in-hospital death after coronary artery bypass grafting (CABG) have been studied in many regions of Canada as possible indicators of hospital-specific quality of care. This nationwide study examined observed and risk-adjusted death rates for 23 Canadian hospitals performing CABG. METHODS: Hospital discharge data were obtained from the Canadian Institute for Health Information and were used to identify all CABG procedures performed in Canadian hospitals in fiscal years 1992/93 through 1995/96. Cases from Quebec hospitals were not studied because hospitals in that province do not report to the institute. Observed death rates were evaluated, and a logistic regression model was used to calculate a risk-adjusted death rate for each hospital for the 4-year period studied. Changes over time in hospital-specific death rates were also examined. RESULTS: A total of 50,357 CABG cases were studied, with an overall death rate of 3.6%. Interhospital comparisons showed that average severity of illness varied considerably across hospitals. Despite risk adjustment accounting for this variable severity, there was considerable variation in adjusted death rates across the 23 hospitals, from 1.95% to 5.76% (p < 0.001 for difference across hospitals). For some hospitals, death rates decreased between 1992/93 and 1995/96, whereas for others the rates were stable or increased. INTERPRETATION: Risk-adjusted rates of in-hospital death after CABG vary widely across Canadian hospitals. There may be differences in quality of care across hospitals, and focused quality-improvement initiatives may be necessary in some institutions.

Full Text

The Full Text of this article is available as a PDF (107.2 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Brook R. H. Health care reform is on the way: do we want to compete on quality? Ann Intern Med. 1994 Jan 1;120(1):84–86. doi: 10.7326/0003-4819-120-1-199401010-00015. [DOI] [PubMed] [Google Scholar]
  2. Brook R. H., McGlynn E. A., Cleary P. D. Quality of health care. Part 2: measuring quality of care. N Engl J Med. 1996 Sep 26;335(13):966–970. doi: 10.1056/NEJM199609263351311. [DOI] [PubMed] [Google Scholar]
  3. Chassin M. R., Hannan E. L., DeBuono B. A. Benefits and hazards of reporting medical outcomes publicly. N Engl J Med. 1996 Feb 8;334(6):394–398. doi: 10.1056/NEJM199602083340611. [DOI] [PubMed] [Google Scholar]
  4. Deyo R. A., Cherkin D. C., Ciol M. A. Adapting a clinical comorbidity index for use with ICD-9-CM administrative databases. J Clin Epidemiol. 1992 Jun;45(6):613–619. doi: 10.1016/0895-4356(92)90133-8. [DOI] [PubMed] [Google Scholar]
  5. Ghali W. A., Ash A. S., Hall R. E., Moskowitz M. A. Statewide quality improvement initiatives and mortality after cardiac surgery. JAMA. 1997 Feb 5;277(5):379–382. [PubMed] [Google Scholar]
  6. Ghali W. A., Quan H., Brant R. Coronary artery bypass grafting in Canada: national and provincial mortality trends, 1992-1995. CMAJ. 1998 Jul 14;159(1):25–31. [PMC free article] [PubMed] [Google Scholar]
  7. Green J., Wintfeld N. Report cards on cardiac surgeons. Assessing New York State's approach. N Engl J Med. 1995 May 4;332(18):1229–1232. doi: 10.1056/NEJM199505043321812. [DOI] [PubMed] [Google Scholar]
  8. Grumbach K., Anderson G. M., Luft H. S., Roos L. L., Brook R. Regionalization of cardiac surgery in the United States and Canada. Geographic access, choice, and outcomes. JAMA. 1995 Oct 25;274(16):1282–1288. [PubMed] [Google Scholar]
  9. Hannan E. L., Kilburn H., Jr, Lindsey M. L., Lewis R. Clinical versus administrative data bases for CABG surgery. Does it matter? Med Care. 1992 Oct;30(10):892–907. doi: 10.1097/00005650-199210000-00002. [DOI] [PubMed] [Google Scholar]
  10. Hannan E. L., Kilburn H., Jr, Racz M., Shields E., Chassin M. R. Improving the outcomes of coronary artery bypass surgery in New York State. JAMA. 1994 Mar 9;271(10):761–766. [PubMed] [Google Scholar]
  11. Hannan E. L., O'Donnell J. F., Kilburn H., Jr, Bernard H. R., Yazici A. Investigation of the relationship between volume and mortality for surgical procedures performed in New York State hospitals. JAMA. 1989 Jul 28;262(4):503–510. [PubMed] [Google Scholar]
  12. Iezzoni L. I. Assessing quality using administrative data. Ann Intern Med. 1997 Oct 15;127(8 Pt 2):666–674. doi: 10.7326/0003-4819-127-8_part_2-199710151-00048. [DOI] [PubMed] [Google Scholar]
  13. Jama J. W., Launer L. J., Witteman J. C., den Breeijen J. H., Breteler M. M., Grobbee D. E., Hofman A. Dietary antioxidants and cognitive function in a population-based sample of older persons. The Rotterdam Study. Am J Epidemiol. 1996 Aug 1;144(3):275–280. doi: 10.1093/oxfordjournals.aje.a008922. [DOI] [PubMed] [Google Scholar]
  14. Landon B., Iezzoni L. I., Ash A. S., Shwartz M., Daley J., Hughes J. S., Mackiernan Y. D. Judging hospitals by severity-adjusted mortality rates: the case of CABG surgery. Inquiry. 1996 Summer;33(2):155–166. [PubMed] [Google Scholar]
  15. O'Connor G. T., Plume S. K., Olmstead E. M., Morton J. R., Maloney C. T., Nugent W. C., Hernandez F., Jr, Clough R., Leavitt B. J., Coffin L. H. A regional intervention to improve the hospital mortality associated with coronary artery bypass graft surgery. The Northern New England Cardiovascular Disease Study Group. JAMA. 1996 Mar 20;275(11):841–846. [PubMed] [Google Scholar]
  16. Pine M., Norusis M., Jones B., Rosenthal G. E. Predictions of hospital mortality rates: a comparison of data sources. Ann Intern Med. 1997 Mar 1;126(5):347–354. doi: 10.7326/0003-4819-126-5-199703010-00002. [DOI] [PubMed] [Google Scholar]
  17. Romano P. S., Roos L. L., Luft H. S., Jollis J. G., Doliszny K. A comparison of administrative versus clinical data: coronary artery bypass surgery as an example. Ischemic Heart Disease Patient Outcomes Research Team. J Clin Epidemiol. 1994 Mar;47(3):249–260. doi: 10.1016/0895-4356(94)90006-x. [DOI] [PubMed] [Google Scholar]
  18. Schneider E. C., Epstein A. M. Influence of cardiac-surgery performance reports on referral practices and access to care. A survey of cardiovascular specialists. N Engl J Med. 1996 Jul 25;335(4):251–256. doi: 10.1056/NEJM199607253350406. [DOI] [PubMed] [Google Scholar]
  19. Topol E. J., Califf R. M. Scorecard cardiovascular medicine. Its impact and future directions. Ann Intern Med. 1994 Jan 1;120(1):65–70. doi: 10.7326/0003-4819-120-1-199401010-00011. [DOI] [PubMed] [Google Scholar]
  20. Tu J. V., Naylor C. D. Coronary artery bypass mortality rates in Ontario. A Canadian approach to quality assurance in cardiac surgery. Steering Committee of the Provincial Adult Cardiac Care Network of Ontario. Circulation. 1996 Nov 15;94(10):2429–2433. doi: 10.1161/01.cir.94.10.2429. [DOI] [PubMed] [Google Scholar]

Articles from CMAJ: Canadian Medical Association Journal are provided here courtesy of Canadian Medical Association

RESOURCES