Trends in coronary artery bypass grafting in Ontario from 1981 to 1989.

OBJECTIVES: To determine the trends in overall and age-specific rates of coronary artery bypass grafting (CABG) in Ontario from 1981 to 1989 and to assess whether relative resource scarcity, as manifested in waiting lists, resulted in obvious age-related or sex-related changes in utilization. DESIGN: Computerized compilation of hospital discharge abstracts from the Hospital Medical Records Institute. All separations for every other year from Apr. 1, 1981, to Mar. 31, 1990, were included. Procedures rather than patients were the unit of analysis (repeat procedures were double-counted if associated with separate hospital admissions). SETTING: Ontario acute care hospitals offering CABG. PATIENTS: People aged 20 years and over who underwent one or more CABG procedures. RESULTS: The overall rate of CABG increased by 31% in the study period, plateauing only between 1983 and 1985. By 1989-90 the rate was 66.03 per 100,000. The highest annual increase in the rate was among people aged 65 to 74 years, at 17.61 procedures per 100,000, as compared with 4.64 per 100,000 among people 75 years and over. In 1989-90 those aged 65 and over represented 37% of the total caseload. The overall male:female ratio did not change significantly throughout the study period. CONCLUSIONS: Since the CABG utilization rate continues to increase in Ontario, recent waiting lists must be due to a disproportionate growth in demand. There was no convincing evidence of age-related or sex-related discrimination in allocating this limited resource. Supply-demand mismatch was driven above all by the continued increase in CABG use among elderly people.