CASE SELECTION AND APPROPRIATENESS OF CORONARY ANGIOGRAPHY AND CORONARY-ARTERY BYPASS GRAFT-SURGERY IN BRITISH-COLUMBIA AND ONTARIO

OBJECTIVES: To compare the types of patients selected for coronary ang iography (CA) and coronary artery bypass graft (CABG) surgery, and the appropriateness of the procedures performed on these patients in a ra ndom sample of cases in British Columbia and Ontario. DESIGN: Retrospe ctive randomized medical record review. SETTING: All hospitals perform ing CA and/or CABG in British Columbia and Ontario in fiscal year 1989 /90. PATIENTS: For CA, 395 randomly selected patients in Ontario and 1 39 randomly selected patients in British Columbia; for CABG, 431 rando mly selected patients in Ontario and 125 randomly selected patients in British Columbia. MAIN OUTCOME MEASURES: Case selection was measured in terms of the demographic and clinical characteristics of patients u ndergoing the procedures. Appropriateness was measured by comparing th e clinical characteristics of patients undergoing the procedures with explicit criteria established by a panel of Canadian physicians. The y ield from CA was measured as the proportion of patients who were found to have insignificant anatomical disease. RESULTS: Analysis of patien ts selected for CA showed that sample patients from Ontario were less likely than those from British Columbia to be female (25% versus 37%, respectively, P=0.012) and less likely to have undergone a previous re vascularization (12% versus 24%, respectively, P=0.005). The distribut ion of main indications for CA differed between the two provinces (P=0 .002), with Ontario patients more likely to have chronic stable angina (45% versus 24%) and less likely to have unstable angina (16% versus 26%). For CABG, sample patients from Ontario were less likely to be 65 years of age or older (32% versus 45%, P=0.016) and more likely to ha ve an ejection fraction less than 35% (14% versus 5%, P=0.006). The di stribution of the main indications for CABG differed (P<0.001), with O ntario patients more likely to have chronic stable angina (68% versus 38%) and less likely to have unstable angina (20% versus 43%). There w as no statistically significant difference in CPI cases rated as inapp ro priate (8.4% in Ontario versus 10.8% in British Columbia, P=0.396) or CABG cases rated as inappropriate (3.9% in Ontario versus 2.4% in B ritish Columbia, P=0.393). There were no statistically significant dif ferences in the proportion of CA that yielded insignificant anatomical disease (17.5% in Ontario versus 18.4% in British Columbia, P=0.355). CONCLUSIONS: There were differences between Ontario and British Colum bia in the demographic and clinical characteristics of patients select ed for CA and CABG. This may indicate differences in the referral proc ess in the two provinces. Despite these differences the rates of inapp ropriate procedures and the yield from CA were similar.