Racial differences in the use of invasive cardiovascular procedures: Review of the literature and prescription for future research

Purpose: The cause of racial disparities in the use of invasive cardiac procedures remains unclear. To summarize, evaluate, and clarify gaps in the literature, studies examining racial differences in cardiac catheterization, percutaneous transluminal coronary angioplasty (PTCA), and coronary artery bypass grafting (CABG) were reviewed. Data Sources: MEDLINE search for English-language articles published from 1966 to May 2000. Study Selection: Empirical studies of adults. Data Extraction: The odds ratios for procedure use by race were examined for each study; cohorts and covariates were also documented. Data Synthesis: Literature was classified as one of three groups on the basis of study design. For the first group, which used administrative data, odds ratios (ORs) for African-American patients compared with white patients ranged from 0.41 to 0.94 for cardiac catheterization, from 0.32 to 0.80 for PTCA, and from 0.23 to 0.68 for CABG. Procedure rates were also lower for Hispanic and Asian patients. In the second group, which used detailed clinical data, African-American patients remained disproportionately less likely to receive cardiac catheterization (OR, 0.03 to 0.85), PTCA (OR, 0.20 to 0.87), and CABG (OR, 0.22 to 0.68). A few studies noted that Hispanic and Asian patients were also disproportionately less likely to receive such procedures. The third group used survey methods but found conflicting results regarding patient refusals as a source of racial variation. Less-educated patients and patients who were not as experienced with the procedure were more likely to decline PTCA. Physician bias was also associated with racial variation in recommendations for treatment. Conclusions: Racial differences in invasive cardiac procedure use were found even after adjustment for disease severity. Future studies should comprehensively and simultaneously examine the full range of patient, physician, and health care system variables related to racial differences in the provision of invasive cardiac procedures.