Racial differences in cardiac revascularization rates: Does "overuse" explain higher rates among white patients?

Background: coronary artery bypass graft (CABG) surgery and percutaneous tr ansluminal coronary angioplasty (PTCA) are well-established treatments for symptomatic coronary artery disease. Previous studies have documented racia l differences in rates of use of these cardiac revascularization procedures . Other studies suggest that these procedures are overused: that is, they a re done for patients with clinically inappropriate indications. Objective: To test the hypothesis that the higher rate of cardiac revascula rization among white patients is associated with a higher prevalence of ove ruse (revascularization for clinically inappropriate indications) among whi te patients than among African-American patients. Design: Observational cohort study using Medicare claims and medical record review. Setting: 173 hospitals in five U.S. states. Participants: A stratified, weighted, random sample of 3960 Medicare benefi ciaries who underwent coronary angiography during 1991 and 1992; 1692 of th ese patients underwent 1711 revascularization procedures within 90 days. Measurements: The proportion of CABG and PTCA procedures rated appropriate, uncertain, and inappropriate according to RAND criteria, and the multivari ate odds of undergoing inappropriate revascularization among African-Americ an patients and white patients. Results: After angiography, rates of PTCA (23% vs. 19%) and CABG surgery (2 9% vs. 17%) were significantly higher among white patients than among Afric an-American patients. The respective rates of inappropriate PTCA and CABG s urgery were 14% and 10%. Among the study states, rates of inappropriate use ranged from 4% to 24% for PTCA and 0% to 14% for CABG surgery. White patie nts were more likely than African-American patients to receive inappropriat e PTCA (15% vs. 9%; different 6 percentage points [95% CI, -0.4 to 12.7 per centage points]), and difference by race was statistically significant amon g men (20% vs. 8%; difference, 12 percentage points [CI, 1.2 to 21.7 percen tage points]). Rates of inappropriate CABG surgery did not differ by race ( 10% in both groups). Conclusions: Among a large and diverse sample of Medicare beneficiaries in five U.S. states, overuse of PTCA was greater among white men than among ot her groups, but this difference did not fully account for racial disparitie s in revascularization. Overuse of cardiac revascularization varied signifi cantly by geographic region.