Twenty-seven years ago, the Revitalization Act of 1993 established legal requirements and guidelines to ensure that the National Institutes of Health (NIH) include women in its clinical research trials. The initiative hasn’t been going so well—and non-government-funded studies don’t seem to be doing any better.
This past February, a study in Circulation showed that while cardiovascular disease (CVD) is the biggest killer of women across the globe, women represented only 38 percent of the participants in CVD trials sponsored by both government and non-government entities from 2010 through 2017. Of the 740 trials in the analysis, most included people ages 61 to 65—that time of life when women’s heart disease rates begin to approach those of men. Yet it was that very age group for which inclusion rates for women were lowest, at 26 percent. Another study, in May, reported that from 2008 to 2017, women accounted for only 36 percent of participants in 143 clinical trials of new heart medications.
This is about where we’ve been since the late 1990s. From 1997 to 2009, only 30 percent, overall, of enrollees in 325 CVD clinical trials were women, a 2012 study in the Journal of General Internal Medicine found.
Excluding women isn’t only an issue of gender inequality. It’s an issue of health. Some diseases, including cardiac conditions, manifest differently in women, and women respond differently to various treatments; thus, study results that focus more on men translate to clinical guidelines that can miss diagnoses in women and miss instances where a particular treatment might not help women and could even harm them.
That would be bad enough if the gender gap in research trials extended only to studies looking at cardiovascular disease. But it exists across the board: Another study published in the past year, in JAMA Network, reported that out of 11 disease categories, women were underrepresented in clinical trials between 1966 and 2018 for seven of them: HIV/AIDS, chronic kidney disease, neoplasms (both benign and malignant tumors), digestive diseases, neurological disorders, hepatitis, and yes, various types of cardiovascular disease. By some measures, the gender bias did improve over time—but not enough to effectively close the gap.
Here’s just one example of how findings in men can play out when applied to women: The insomnia drug zolpidem (Ambien) is metabolized more slowly in women than in men—a factor that may have contributed to multiple car crashes, prompting the FDA to require that the recommended dose for women be halved.
It isn’t just women who are affected by disparities in clinical research. Ethnic and racial minority groups also remain underrepresented. The Revitalization Act of 1993 mandated that minorities as well as women be included in the design of future studies, but on that front, too, scientific inquiry lags. It’s as if the world has moved on but all the important roles in medical research are still being played by men in fedoras from 1940s movies, with women and minorities in bit parts, at best.
Even the people in charge of vetting the research remain mostly men in many cases. Though there are four to six times as many women in academic medicine today as in 1970, only 13 percent of researchers on the editorial boards of three prominent cardiology journals in 2018 were women, according to another report published in the same issue of Circulation noted above. That’s up from 6 percent in 1998 but still a very low proportion.
During the slow catch-up, if you are not a white man and a doctor diagnoses you with an illness or prescribes a treatment, it is more than reasonable for you to ask how well the disorder has been studied in people of your gender or race or ethnicity. You won’t change the state of research with that one question, but at least you’ll be forcing an awareness that there are disparities in medical knowledge pertaining to serious diseases that affect all people. And I’m optimistic that greater awareness can lead to real change.
This article first appeared in the UC Berkeley Wellness Letter.
Also see Heart Disease: A Woman’s Problem.