March 1, 2011 -- Despite federal mandates to include more women in research studies, women are often underrepresented in trials evaluating cardiac stents, implantable defibrillators, and other high-risk cardiac devices.
The findings, which appear in Circulation: Cardiovascular Quality and Outcomes, reflect many of the sentiments expressed in the 2011 update to the American Heart Association’s cardiovascular prevention guidelines for women. The new guidelines call for more male- and female-specific results, especially regarding risks from preventive therapies such as aspirin.
Official efforts aimed at including gender-specific information in studies dates back to 1994, when the Center for Devices and Radiological Health enacted a policy to address gender bias in submission forms for new medical devices. This is the same year that the FDA established the Office of Women’s Heath.
More Than 50% of Studies Don’t Include Gender Analysis
Researchers analyzed 123 studies of 78 cardiac devices that received pre-market approval from the FDA for men and women from 2000 to 2007. Of 123 studies, there was no information on the sex of participants in 28% of studies. Among those that did report gender, 67% of participants were men, on average.
The FDA had instituted a policy to analyze gender bias in all device applications, but more than half of these studies did not include such an analysis. Twelve of 47 studies that did include this summary noted that there was a difference seen in the device’s safety or efficacy in women, compared with men.
There was no uptick seen in the number of women enrolled in studies over the course of the study.
Many Reasons for Gender Gap in Studies
Why the gender gap? The study authors suggest that the number of women with certain heart conditions may be underestimated. Researchers who have had approved applications have also said that their gender breakdown was similar to that of an older study without acknowledging the older study included greater proportions of men. Women may be less likely to be referred to specialists, which could also affect recruitment.
Study authors, who were led by Rita F. Redberg, MD, professor of medicine and the director of Women’s Cardiovascular Services at the University of California in San Francisco, call for meaningful changes to the study review and approval process.
For example, the Heart Disease Education, Analysis and Treatment for Women Act, if passed, would mandate sex-specific data reporting and could help address the disparities seen in the new study.
They also suggest that approval applications be returned to the sender unless gender-specific data are included.
Room for Improvement
“We still have a long way to go to make sure that therapies are tested in women,” says Nieca Goldberg, MD, director of the Women’s Heart Program at New York University’s Langone Medical Center in New York City. “We need to make it easier for women to become aware of clinical trials and make it easier for them to enroll.”