The study used a retrospective quasi-experimental population-based epidemiology design to examine the characteristics of the health care provider and the individual patient that account for utilization of TCCS. The study had four specific aims: 1) to determine the patient and provider characteristics exclusive of symptomatology that predict Black-white differences in referral for coronary angiography; 2) to determine, for patients who are referred for coronary angiography, the patient and provider characteristics that predict Black-white differences in receipt of coronary angiography; 3) to determine the patient and provider characteristics exclusive of symptomatology that predict Black-white difference in referral for CABG and PTCA; 4) to determine, for patients who are referred for CABG or PTCA, the patient and provider characteristics that predict Black-white differences in receipt of CABG and PTCA.