Lower Rates of Cardiac Diagnostic Procedure Use in Women Restricted to Cases Where Indications are Unclear, Yale Researchers Report
Published in the September 17 issue of the Annals of Internal Medicine, the study showed that elderly women were 10 percent less likely to undergo cardiac catheterization after a heart attack than men. However, most of this difference was due to other characteristics that differed between men and women - and was reduced to two percent when accounting for those other factors.
Importantly, the researchers found that men and women who were considered to be appropriate candidates for cardiac catheterization underwent the procedure at the same rate (44 percent). Men and women who were unlikely to benefit from cardiac catheterization also underwent the procedure at the same rate (17 percent). Women were only less likely to undergo cardiac catheterization when the clinical benefits of the procedure were unclear - and this difference was only three percent.
“These data provide strong evidence that most sex differences in treatment after a heart attack are due to clinical considerations or factors other than the patient’s sex,” said Harlan Krumholz, professor of medicine at Yale School of Medicine, director of the Yale-New Haven Hospital Center for Outcomes Research and Evaluation, and the senior author on the study.
The issue of disparities in health care and outcomes has received significant attention. However, Krumholz noted that most investigators have focused on documenting differences in care by sex, but this investigation extends previous work by determining whether differences in treatment reflected appropriate or inappropriate treatment.
“Reassuringly, we found no gender differences in cardiac catheterization rates when it was clear that a patient needed, or did not need, the procedure,” said the study’s first author, Saif Rathore, lecturer in the Department of Internal Medicine at Yale School of Medicine. “We believe our data indicate that a patient’s sex doesn’t influence a physician’s decision making in cases where treatment decisions are clear.”
Using data from the Cooperative Cardiovascular Project, a federal initiative to improve the care of Medicare patients hospitalized for acute myocardial infarction in 1994 and 1996, the team evaluated 143,444 patients to determine whether differences between men and women in the use of cardiac catheterization varied according to their appropriateness for undergoing the procedure.
Krumholz said the findings underscore the complexity of this issue. “We did find a difference in the rates of cardiac catheterization among patients with equivocal indications for treatment. Because it is not clear that these patients would benefit from undergoing cardiac catheterization, we can’t be sure that gender differences in this group represent inappropriate treatment of women or men. The reasons for this difference are unclear.” Other authors on the study were Martha Radford, M.D., associate professor of medicine at Yale, Yongfei Wang, statistical analyst, and Diana Ordin, M.D., researcher at the Centers for Medicare and Medicaid Services.