September 12, 2019

Are NIH Policies Unintentionally Impeding Women’s Health Research?

By Emily Ortman, SWHR Communications Director

For most of scientific history, researchers did not study women. They (wrongly) assumed that women were just “hormonal” versions of men and that women’s menstrual cycles made them more difficult to study. Female animals were also excluded for this reason.

This longtime bias in medical research (highlighted in a recent episode of Last Week Tonight with John Oliver) resulted in a huge gap in understanding of women’s health and how women differ from men in health and disease.

“Men were treated as the default human, which put women’s bodies in danger,” Dr. Liisa Galea explains in her recent VICE article, “I Should Be Allowed to Leave Men Out of My Studies.” Galea (pictured above) is a professor in the Department of Psychology at the University of British Columbia and scientific advisor at the Women’s Health Research Institute at BC Women’s Hospital.

About 25 years ago, the scientific community began to address this disparity when the U.S. Congress passed a law requiring clinical research funded by the National Institutes of Health (NIH) to include women. Then, in 2016, NIH implemented a policy requiring researchers to consider sex as a biological variable (SABV) in all preclinical work funded by NIH.

While these policies intended to correct imbalances in studying females, Galea argues that the new movement on including sex as a biological variable has backfired somewhat in implementation.

“Women’s health researchers are being asked to add men into their studies in order to provide balance, even if it doesn’t make scientific sense,” she writes, citing examples of grant applications and research papers for studying women’s health topics (such as inflammation in the placenta) being rejected for not including males. She argues that if the point of requiring inclusion of sex as a biological variable is because we don’t know enough about females, then she shouldn’t be forced to incorporate males into her women’s health-focused research.

“Women’s health, female health is much more than how we differ from males or men,” Galea wrote recently in a Twitter thread. “It’s how experiences change our physiology, perceptions, epigenetics & many female experiences are female-specific,” such as pregnancy, the postpartum period, and menopause.

She cites great progress made in diseases that only or mainly affect one sex — specifically prostate and breast cancer. Over the past 35 years, the relative five-year survival rates have increased by 33% in prostate cancer and by 16% in female-only breast cancer in the U.S., while the survival rates for lung, bladder, or thyroid cancer have only improved by 5% to 8%. “There is also the intriguing possibility that when a body of research considers only one sex, the improvements for treatment can also improve dramatically for that one sex,” Galea writes.

In addition, even if researchers do include both sexes, that doesn’t guarantee they will appropriately analyze their results by sex. Despite NIH-funded clinical trials being required to use both sexes since 1993, data show that only 26% of these trials published in 2015 reported at least one outcome by sex or explicitly included sex as a covariate in statistical analysis. “When data is blended, we obscure important information about how a drug or a disease affects females and males differently,” Galea explains.

When comparing the 2015 results to previously reported results from 2004 and 2009, researchers found no statistically significant changes, concluding that “NIH policies have not resulted in significant increases in reporting results by sex, race, or ethnicity.”

Galea emphasized the need for funders, policymakers, and reviewers to understand the history of women’s health research (or lack thereof) and support more funding for women’s health-specific research to close the knowledge gaps.

For example, research on migraine and endometriosis, diseases that disproportionately or exclusively affect women, is underfunded — especially when considering the burden of disability associated these diseases. Migraine and headache disorders receive the lowest amount of NIH funding when compared to conditions with the same level of disease burden. Similarly, endometriosis received just $7 million in NIH funding in fiscal year 2018, putting it near the very bottom of NIH’s 285 disease/research areas.

“Studying one sex, particularly females, I would argue is exactly what will drive forward knowledge on women’s health & reduce disparities in our knowledge of what matters to women’s health,” Galea says.