The National Institutes of Health (NIH) has long been a key source of funding for medical research, but it wasn’t until 1986 that the agency formally established a policy of including women in clinical research. For decades, women received drugs and therapies that had been tested only on men, even though the same diseases can affect men and women differently, and women may metabolize drugs differently than men do.

In 1993, the NIH Revitalization Act put into law the requirement for women’s inclusion in NIH-funded clinical research. In 2010, the Institute of Medicine reported, “women’s health research has contributed to significant progress over the past 20 years in lessening the burden of disease and reducing deaths from some conditions, while other conditions have seen only moderate change or even little or no change.” A new report from the Government Accountability Office on women’s inclusion in research comes to a similar conclusion: NIH has made progress, but still must do more to ensure that federally funded research can be used to improve care for both women and men.

At the request of several members of Congress, the GAO examined women’s enrollment in NIH-funded clinical trials as well as NIH efforts to monitor trials’ design and implementation for their ability to address potential sex differences. The GAO found that when considering all NIH clinical research as a whole, more women than men have been enrolled every year since 2005. However, GAO found that it was harder to assess the sex breakdown of research participants for research on a specific medical condition, such as obesity, to see if women might be underrepresented in certain studies. The GAO report also notes that although NIH collects enrollment data by sex from each of its institutes and centers, it doesn’t share that data with the public.

Researchers who apply to NIH for funding of phase III clinical trials (the stage that typically involves hundreds of participants) must “assess whether an analysis of potential sex differences is merited, and if so, develop a plan to analyze study results accordingly.” NIH relies on the peer reviewers who evaluate funding applications to consider this aspect of proposals; after awards are made, NIH program officers monitor the researchers’ progress. The program officers’ knowledge about individual studies’ analysis of sex differences isn’t sufficiently aggregated, though — and, the GAO investigation found, that may be due to outdated reporting systems:

Currently, program officers review awardees’ progress reports—including any information reported regarding the analysis of potential sex differences—but do not have means, such as a written checklist or a required field in an electronic reporting system, for recording the information obtained through this monitoring, as they do for monitoring enrollment. NIH’s awardee data system includes information on whether individual awards include phase III trials. However, the data system does not have a data element that denotes whether an awardee’s study should include or has plans for an analysis of potential sex differences.

It sounds like a fix is in progress, though:

NIH officials also told us that they plan to add a question for this type of monitoring to the existing electronic checklist used by program officers in the fall of this year, to be implemented for awards funded in fiscal year 2016.

Another proposed NIH policy in the works is to require all NIH-funded clinical trials to register and submit summary results, including the sex of participants, to the ClinicalTrials.gov database. (Registration is currently only required for trials of FDA-regulated drugs and devices.) Sex-specific results would only have to be reported if these were among the pre-specified primary and secondary outcome measures, though. In other words, researchers would have to report the number of women and men enrolled in a trial, but would only have to report if an intervention was more or less effective in women if that was one of the main questions they had planned to investigate.

Overall, it seems that NIH is making progress on assuring that taxpayer-funded clinical research addresses potential sex differences that were ignored for too long. But clinical research is only one piece of a larger picture. As a report published last year by the Mary Horrigan Connors Center for Women’s Health at Brigham and Women’s Hospital explains, sex needs to be considered at every stage of research – from early lab research, to clinical trials, to translating research results into clinical practice and, finally, understanding health outcomes in both women and men.

Upon receiving the results of this new GAO report, Senator Barbara Mikulski (D-MD) summarized the big picture:

Twenty-five years ago, women did not have much to celebrate when it came to scientific advances – we weren’t even at the table. Now researchers look at disease in a gender-specific way, and we’ve made great strides in breast cancer and cervical cancer research, AIDS research, and mapping the human genome. We must continue to raise awareness, raise consciousness and raise hell so that women are not left behind when it comes to their health.

Senator Mikulski has announced that she will leave the Senate next year after five terms. I hope her successor will be as strong a champion for women’s health as she has been.