Referrals to high-quality cardiac surgeons: patients' race and characteristics of their physicians

Abstract

Objective: To examine the referral process to cardiac surgeons in order to explain racial disparities in access to high-quality cardiac surgeons.

Data sources/study settings: All white and black Medicare fee-for-service patients undergoing coronary artery bypass graft (CABG) surgery in New York State during 1997-1999.

Study design: A retrospective analysis of referral patterns for white and black patients in relation to the quality of the cardiac surgeon, measured by the surgeon's risk-adjusted mortality rate (RAMR), and in relation to characteristics of the physician providing the majority of cardiac care before the surgery. The average RAMRs of the surgeons to whom different physicians referred patients were compared using t-tests and paired t-tests. A hierarchical multivariate regression model was estimated to test hypotheses about the effect of physicians' characteristics on referrals of blacks to low-quality surgeons.

Data extraction method: Variables were constructed from Medicare claims.

Principal findings: The differential in surgeons' quality for white and black patients is partially due to the physician providing the majority of cardiac care before the surgery. There is both across- and within-physician variation in referrals. Of the physician characteristics investigated, only the number of black patients referred to CABG and the percent of all cardiac referrals to the same hospital decrease the difference in surgeons' quality between whites and blacks.

Conclusions: Several different pathways lead blacks to cardiac surgeons of lower quality. Further research is needed to understand the causes and inform policies designed to minimize disparities in access to high-quality providers.

Figure 1

Referral to Cardiac Surgeon for Coronary Artery Bypass Graft (CABG) Surgery. The shaded ovals represent decision nodes at which the choice of a cardiac surgeon or a subset of surgeons may be determined.