Scientists continue to neglect gender in medical research, endangering women’s health by focusing on males in studies that shape the treatment of disease, a report found.
The lack of attention to gender differences occurs at all stages of research, from lab to doctor’s office, according to the report released today by the Connors Center for Women’s Health at Brigham and Women’s Hospital in Boston, and the Jacobs Institute of Women’s Health at George Washington University in Washington. Animal and human studies typically use male subjects and, even when females are included, researchers fail to analyze and report results by sex, the authors said.
“We’ve got to do the work and change the way science is done and translated to clinical care,” Paula Johnson, executive director of the Connors Center, said in a telephone interview. “Until we do that, we are putting women’s health at risk.”
Congress passed the 1993 National Institutes of Health Revitalization Act requiring that NIH-funded biomedical research with human subjects include and analyze the effects on woman and ethnic minorities. The legislation doesn’t extend beyond research funded by the NIH and doesn’t apply to animal or cellular studies.
“More often, studies ‘control’ for sex differences instead of investigating them, but this approach is inadequate when the mechanisms underlying health may operate differently in men and women,” the report’s authors wrote.
For example, more women than men die of cardiovascular disease, while only one-third of cardiovascular clinical trial subjects are female and less than one-third of clinical trials that include women report outcomes by sex, the report found.
Plaque that causes heart disease is more diffusely deposited in women’s arteries, so the “so-called gold standard test,” cardiac catheterization, which shoots dye into the arteries, may be inadequate for women, Johnson said during a conference call with reporters.
“We do have the technology to go into the artery with a small ultrasound probe, or measure the flow across the artery,” she said, though doctors “have to be thinking about, and have knowledge that these sex differences do occur.”
While estrogen is suspected to increase women’s susceptibility to lung cancer, and may explain why female non-smokers are three times more likely to get lung cancer than their male counterparts, current research often fails to stratify data based on gender-specific factors, according to the report.
Women are also 70 percent more likely to suffer depression than men, yet animal studies on brain disorders that rely exclusively on males outnumber studies in females 5.5 to 1, the authors said.
The report echoes previous reviews dating to at least 1985 when a U.S. Public Health Service task force found that “lack of research focus on women’s health concerns has compromised the quality of health information available to women as well as the health care they receive.” More recently, the Institute of Medicine found in 2010 that progress had been made in some conditions but had slowed or stalled in others.
The report’s authors said money can be a barrier to more gender-aware research. To include women and female animals in adequate numbers, researchers need to increase the sample sizes of their studies, which takes more funding, the authors said.
Yet researchers are missing easy opportunities that wouldn’t need extra funding, Johnson said.
“For studies that already include women and female animals, reporting data by sex is critically important and that’s not routinely done,” she said. “We’re not getting the value for our added research dollars.”
The report had a wide-ranging list of recommendations, which include asking the Food and Drug Administration to require all medical evaluations include efficacy and safety data separately for men and women.
The FDA takes action when variations between gender are suspected, Sandra Kweder, the agency’s deputy director of the Office of New Drugs, said Feb. 14 in a blog post. Kweder cited the example of the FDA’s updated guidelines for women to take a lower dose of sleep medications such as Ambien, which are cleared from women’s bodies slower than men.
“We’ll continue to advocate for the inclusion of women in clinical trials and for analyses of how their bodies process medications,” Kweder wrote.
The agency also is “working on an action plan that would evaluate how to enhance the inclusion and analysis of subgroups in medical product applications as well as how that information is or should be communicated to patients and health-care professionals,” Tara Goodin, a spokeswoman, said in an e-mail.
The authors also asked peer-reviewed journals to disclose basic information about whether published studies address sex differences and whether the subjects included women or female animals.
The authors “certainly make a good case for our authors, reviewers, and editors to be more alert to the need to report gender factors in biomedical research and to look for evidence for gender differences in disease and disease response,” Marcia McNutt, editor-in-chief of the journal Science, said in an e-mail.
Jim Michalski, spokesman for the Journal of the American Medical Association, declined to comment on whether the publication would make any changes.
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