Why Don’t Medical Studies Include Equal Numbers of Men and Women?

By
Photo: Blake Sinclair

Women are underrepresented in medical research, only making up one-third of participants in studies testing drugs and medical devices. The latest episode of Mother Jones’s Inquiring Minds podcast teases out some of the reasons why this is true and why it’s harmful.

The hosts spoke with Marek Glezerman, professor emeritus of obstetrics and gynecology at the Sackler School of Medicine in Tel Aviv, who pointed out that, for starters, women have monthly hormonal shifts that men do not, so their menstrual cycles could end up affecting study results. Some women may be hesitant to participate in research on new drugs if they’re trying to get pregnant or are concerned about lasting effects on their reproductive systems.

Physiological differences mean that women tend to need more sleep than men, and women feel pain differently and process certain drugs differently, too. Women are more likely to experience adverse drug reactions, and yet dosing isn’t broken down by sex. Glezerman says it’s “fundamentally wrong” to treat women based on research conducted on men. In the small amount of studies where women are subjects for drug and device trials, men’s and women’s results are likely to be lumped together, not reported separately, per a report from Brigham and Women’s Hospital. He hopes that, in the future, there will be different medicines for men and women, but accurate dosages would be a great start.

This bias extends to exercise-science and sports-medicine research, like the strength-training study that made the rounds earlier this week. Some sports-medicine studies have included women at the early stages of their cycles but, uh, active women tend to work out all month long.

Others have explained that women’s underrepresentation starts way before human trials, with preclinical studies on cells and animals that are used to determine whether to move forward with research. After the passage of the 1993 National Institutes of Health Revitalization Act, which required the inclusion of women and minorities in government-funded research, human trials have achieved parity, but cell and animal research has not. It should start from the beginning.

Meanwhile, there is lots of research that doesn’t receive government money and isn’t held to the same standards. Researchers might think it’s more expensive to “duplicate” their results in animals by using males and females, but Teresa Woodruff, the director of the Women’s Health Research Institute at Northwestern, told The Atlantic in 2014 that’s the wrong way of looking at it.

“In the end, it serves the public better that we understand about sex at the cheaper end of the equation, before it gets so much more expensive as you go closer to clinical trials. It is going to be better in the long run, less costly, for us to have inclusion of both sexes in basic science.”