CHICAGO -- A study of 113,000 heart attack victims found that people with mental illnesses are much less likely to receive a bypass, angioplasty or other common, aggressive treatments.
Previous research has found similar disparities in cardiac treatment for women and blacks. The researchers in the new study suggested that for the mentally ill, bias among doctors is at play.
"These differences in procedure rates could be used as a marker for potentially larger difficulties in the health care system," said Dr. Benjamin G. Druss, an assistant professor of psychiatry at Yale University. "They are a red flag that we need to look at the issue more carefully."
The study was published in Wednesday's Journal of the American Medical Association.
The authors reviewed data on Medicare recipients nationwide ages 65 and older who were hospitalized for heart attacks in 1994 and 1995. Of those, 5,365 had been diagnosed with mental disorders such as schizophrenia, depression and substance abuse.
The researchers examined what procedures the patients received, including cardiac catheterization -- the "gold standard" diagnostic test for heart disease. It involves squirting dye into cardiac arteries and X-raying them to locate blockages and determine whether treatments such as angioplasty or bypass surgery should follow.
Mental patients were 28 percent less likely to undergo catheterization, 25 percent less likely to undergo angioplasty -- in which a tiny balloon is inflated inside an artery to clear away fatty buildup -- and 32 percent less likely to have bypass surgery.
There were no significant differences in the death rates for both groups within 30 days of hospital admission. However, Druss said that finding is not as important as possible differences in the long-term outcome. The study did not look beyond 30 days.
The researchers said possible reasons for the treatment disparities include the attitudes of mental patients and the doctors who treat them.
Some patients might reject a doctor's recommendations or be unable to give informed consent about treatment. The researchers also said doctors might fear mental patients would be unable to adhere to treatment regimens or might feel they are less deserving of aggressive care.
"Mental disorders continue to carry stigma in both the general community and medical settings," the researchers wrote.
Dr. Roy Ziegelstein, a cardiologist at Johns Hopkins Bayview Medical Center in Baltimore, said the study "raises an incredibly important issue, and that is, are people treated differently medically as a result of something other than the medical disorder?"
"It doesn't really answer the question," he said. "It puts it on the radar screen as an important issue to look at."