Racial Disparities Exist in Diagnostic Procedure for Heart Attack Patients, Regardless of Doctor's Race, Yale Researchers Report

In one of the largest national studies on the topic, Yale researchers have demonstrated a marked racial difference in the rate of cardiac catheterization, a diagnostic procedure used to assess heart function after a myocardial infarction or heart attack.

These differences in practice, researchers say, are present whether or not the patients received care from a black physician or a white physician.

Published in the May 10 issue of the New England Journal of Medicine, the study showed that cardiac catheterization rates for white patients were almost 40 percent higher than cardiac catheterization rates for black patients, even after adjusting for clinical differences between the groups. For every 100 black patients with a heart attack, 12 fewer patients underwent cardiac catheterization compared with similar white patients.

“Despite these differences in care, survival was similar among black and white patients up to three years after their hospitalization for the heart attack,” said Harlan Krumholz, M.D., associate professor of internal medicine and cardiology at Yale School of Medicine and senior author on the study.

The issue of racial disparities in health care and outcomes has received substantial attention. Krumholz said most investigations have focused on documenting differences in care by race or sex, but his investigation extends previous work by examining the effect of physician race on differences in care.

“Concerns that racial differences in procedure use only reflected the behaviors of white physicians are not supported by the findings,” said Jersey Chen, M.D., first author and a medical student at the time the study was completed. “Racial differences in cardiac catheterization rates were also present among patients who received care from black physicians.”

Using data from the Cooperative Cardiovascular Project, a study of Medicare beneficiaries hospitalized for acute myocardial infarction in 1994 and 1995, the team evaluated whether disparities between black and white patients in the use of cardiac catheterization varied according to the race of their attending physician.

They found that of 35,676 white and 4,039 black patients with acute myocardial infarction, physicians of both races referred white patients for catheterization about 40 percent more often than black patients.

“While the study cannot preclude the existence of racial bias or prejudice, it does suggest that if physician factors contribute to racial differences in cardiac catheterization use, be it by beliefs or attitudes, then these factors are apparently common to both white physicians and black physicians,” said Saif Rathore, a co-author on the study.

Krumholz said the findings underscore the complexity of the issue. “We did find substantial differences in the rates of cardiac catheterization that could not be explained by racial differences in the clinical characteristics of the patients, their physicians, or the type of hospitals where they received treatment,” he said. “We could not illuminate the reasons for these differences.”

“The fact that survival rates among both races were similar despite differences in procedure use is an interesting feature of this study,” Krumholz added. “We could find no evidence that these differences in procedure use translated into differences in survival. The finding raises the question about whether the referral rate was too high for white patients rather than being too low for black patients. We would need more information about the indications for the procedures and the health outcomes of the patients to investigate this issue further.”

As part of the Cooperative Cardiovascular Project, medical records from more than 200,000 hospitalizations nationwide were abstracted for information and analyzed for quality of care. Faculty from Yale, including Krumholz and Martha Radford, M.D., participated in the planning and implementation of the Health Care Financing Administration Project.

Study authors included Krumholz, Chen, Rathore, Radford and data manager, Yun Wang.