Use of coronary artery bypass surgery in the United States and Canada. Influence of age and income

Objective. —To compare overall rates of coronary artery bypass surgery (CABS) in several Canadian and US jurisdictions and to compare use by age and income groups in the two countries. Design. —Survey, using computerized hospital discharge abstracts. Setting. —All nonfederal hospitals in New York, California, Ontario, Manitoba, and British Columbia between 1983 and 1989. Patients. —All adult residents of the five jurisdictions who underwent CABS in a hospital in their jurisdiction. Results. —Between 1983 and 1989, the CABS rates were consistently highest in California and lowest in the Canadian jurisdictions. In 1989, the age-adjusted rate of CABS in California (112.5/100 000 adults) was 27% higher than in New York (88.4/100 000) and 80% higher than in the three Canadian provinces combined (62.4/100 000). The CABS rates increased for those aged 65 years and older and decreased for those aged 20 to 54 years in all five jurisdictions. In 1989, CABS rates were three times higher in California than in Canada for those aged 75 years and older, and the higher rates for those aged 65 years and older accounted for 75% of the overall difference in rates between California and Canada. In Canada, CABS rates for the nonelderly varied little by income of area of residence, but in New York and California, rates increased steadily with the income of area of residence. Conclusion. —Control over the supply of resources in Canada is associated with markedly lower CABS rates for the elderly than found in the United States. While overall rates are lower in Canada, the Canadian universal health insurance system reduces the influence of income on access to CABS found in the United States. However, even without universal health insurance, CABS rates for the nonelderly living in the poorest areas in California are similar to the rates for those living in the poorest parts of Canada. (JAMA. 1993;269:1661-1666)