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September 28, 1994

Comparison of the Appropriateness of Coronary Angiography and Coronary Artery Bypass Graft Surgery Between Canada and New York State

Author Affiliations

From RAND, Santa Monica, Calif (Drs McGlynn, Leape, Park, Hilborne, and Brook and Mss Keesey, McDonald, and Damberg); Sunnybrook Health Science Centre, University of Toronto (Ontario) (Drs Naylor and Goldman), the Institute for Clinical Evaluative Sciences, Toronto (Drs Naylor and Anderson and Ms Pinfold); the Departments of Medicine (Drs Hilborne and Brook) and Pathology and Laboratory Medicine (Dr Hilborne), the School of Medicine (Drs Hilborne and Brook) and the School of Public Health (Dr Brook), UCLA, Los Angeles, Calif; Harvard School of Public Health, Boston, Mass (Dr Leape); the Schools of Medicine and Public Health, University of Michigan, Ann Arbor (Dr Bernstein); St. Michael's Hospital, Toronto (Dr Armstrong); and Value Health Sciences Inc, Santa Monica, Calif (Dr Sherwood).

JAMA. 1994;272(12):934-940. doi:10.1001/jama.1994.03520120044029

Objective.  —To compare the appropriateness of coronary angiography and coronary artery bypass graft (CABG) use between the United States and Canada.

Design.  —Retrospective randomized medical record review.

Setting.  —All hospitals performing coronary angiography and/or CABG surgery in two Canadian provinces (Ontario and British Columbia); in New York State, 15 randomly selected hospitals that provide coronary angiography and 15 randomly selected hospitals that provide CABG surgery.

Patients.  —All patients were randomly selected. For coronary angiography, 533 patients in Canada and 1333 patients in New York were selected; for CABG, 556 patients in Canada and 1336 patients in New York were selected.

Main Outcome Measures.  —Percentage of patients in each country who had coronary angiography or CABG for necessary, appropriate, uncertain, or inappropriate indications as rated by criteria developed separately in each country and the complications of those procedures.

Results.  —For coronary angiography, 9% of Canadian cases and 10% of New York cases were rated inappropriate using Canadian criteria compared with 5% and 4%, respectively, using US criteria. For CABG, 4% of Canadian cases and 6% of New York cases were rated inappropriate by Canadian criteria compared with 3% and 2%, respectively, using US criteria. A lower proportion of procedures were performed on persons aged 75 years or older in Canada than in New York for both coronary angiography (5% vs 11%; P<.001) and CABG (6% vs 14%; P<.001). Women were also represented in lower proportions among angiography cases in Canada than in New York (28% vs 35%; P=.023). Canadian patients with left main coronary disease waited significantly longer between angiography and CABG than did New York patients (P<.0001).

Conclusions.  —Rates of inappropriate use of cardiac procedures were low in Canada and New York, which suggests that the regionalization of cardiac procedures that characterizes both health care systems contributes to better clinical decision making. Differences in the use of cardiac procedures among the elderly in the two countries merits further comparative examination.(JAMA. 1994;272:934-940)