Geographical Distribution of Surgical Capabilities and Disparities in the Use of High-Volume Providers The Case of Coronary Artery Bypass Graft

Background: Previous studies have documented substantial differences by patient race/ethnicity and insurance in the use of high-volume surgical providers. The extent to which regional availability of surgical capabilities explains such differences has not been examined. Objectives: To examine the existence of racial/ethnic and payer differences in using high-volume hospitals and surgeons for coronary artery bypass graft (CABG) in the state of Florida and to study the role of regional availability of high-volume providers in explaining the differences. Research Design: We conducted descriptive analysis of the distribution of CABG providers and patient populations by race/ethnicity and insurance across the 19 Hospital Referral Regions (HRRs) in Florida. We estimated logistic regressions of using a high-volume provider to derive estimates of overall group differences. We further estimated models with HRR fixed effects to derive within-HRR differences. We derived implications by comparing findings based on the 2 sets of models. Results: Non-Hispanic black patients were 58% as likely (95% CI: 52%, 65%), Hispanic patients were 84% as likely (95% Cl: 77%, 90%), to have received CABGs at a high-volume hospital, compared with non-Hispanic whites. Controlling for inter-HRR differences eliminated almost all racial/ethnic differences. Substantial differences in using high-volume providers existed between Medicaid/uninsured and privately insured patients and such differences persisted within HRRs. Conclusions: Unequal distribution of CABG capabilities coupled with racial/ethnic concentration in residence across Florida HRRs accounted for almost all racial/ethnic differences in using high-volume hospitals. Factors other than availability of surgical resources were responsible for differences between Medicaid/uninsured and privately insured patients.