Racial and community factors influencing coronary artery bypass graft surgery rates for all 1986 Medicare patients

Objective. —This study examines the differences in the rates of coronary artery bypass grafting (CABG) between white and black Medicare patients. Design. —This is a cross-sectional study with data from the 1986 Health Care Financing Administration hospital claims records on all Medicare patients, the 1988 update of the Bureau of Health Professions area resource file, and the 1985 Census Bureau's county population estimates file. Setting. —Data are from all Medicare patients in the United States in 1986. Main Outcome Measures. —Sex- and age-adjusted CABG rates for whites and blacks over the age of 65 years were computed for each of 50 states and 305 Standard Metropolitan Statistical Areas (SMSAs). Results. —Nationally the CABG rate was 27.1 per 10000 for whites (40.4 for white men and 16.2 for white women), but only 7.6 for blacks (9.3 for black men and 6.4 for black women). Racial differences were greater in the Southeast, particularly in nonmetropolitan areas, than in other regions. Neither white nor black SMSA rates were associated with the rate of admission for acute myocardial infarction (an indication of the amount of coronary artery disease). White rates, but not black rates, were associated with the number of thoracic surgeons per 100 000 people. Conclusions. —For patients insured by Medicare, race is strongly associated with CABG rates, and this association is greater for men than for women and greater in the Southeast than in other parts of the country. Physician supply may relate to the CABG rates for whites. (JAMA. 1992;267:1473-1477)