NIH-Funded Research Fails to Report Sex Differences Despite Decade-Old Requirement

A Northwestern University study published in Nature Communications Medicine found that only 44% of 574 NIH-funded papers published between 2017 and 2024 reported results by sex, despite a 2016 NIH policy requiring researchers to consider sex as a biological variable. The compliance gap is even worse for non-human studies, where only 28% analyzed findings by sex, and 13% of all publications fail to disclose subject sex at all. Research led by women shows significantly higher compliance, with 58% of papers with female first and senior authors analyzing data by sex compared to just 39% for male-led papers. The findings come amid broader concerns about declining NIH investment in women's health research, with a National Academies report showing the proportion of NIH budget spent on women's health has decreased even as overall funding increased, and a Washington Post analysis revealing NIH grants mentioning women have fallen to decade lows.

Low Compliance with NIH Sex-Inclusivity Requirements

• ▪The National Institutes of Health mandated the inclusion of women and racial and ethnic diversity in clinical trials in 1993.
• ▪The National Institutes of Health established the Office of Women's Health Research in 1993.
• ▪Nicole Woitowich is the executive director of the Northwestern University Clinical and Translational Sciences Institute.
• ▪Only 4% of NIH-funded papers discuss their rationale for how they approached sex as a biological variable.
• ▪13% of NIH-funded publications do not disclose the sex of their subjects.
• ▪A Northwestern University study examined 574 NIH-funded papers published between 2017 and 2024.
• ▪61% of NIH-funded papers published between 2017 and 2024 included both sexes as subjects.
• ▪Only 44% of NIH-funded papers published between 2017 and 2024 reported their results by sex.
• ▪The Northwestern University study on NIH-funded research was published on Monday in Nature Communications Medicine.

Gaps in Non-Human Subject Research

• ▪19% of non-human subject studies in NIH-funded research did not disclose sex information at all.
• ▪Only 50% of non-human subject studies in NIH-funded research reported their findings by sex.
• ▪41% of non-human subject studies in NIH-funded research included both sexes.
• ▪Anne Murphy is director of the neuroscience institute at Georgia State University.

Impact of Female Authorship on Sex-Based Analysis

• ▪39% of NIH-funded papers with a male lead author analyzed data by sex.
• ▪58% of NIH-funded papers with both a woman first author and woman senior author analyzed data by sex.

Trump Administration Policies Threatening Women's Health Research

• ▪Tom Babor is a professor emeritus at the University of Connecticut School of Medicine.
• ▪Tom Babor is one of the researchers who developed the Sex and Gender Equity in Research guidelines.
• ▪Alina Salganicoff co-chaired a National Academies committee that assessed NIH women's health research.

Perspective of Nicole Woitowich and Northwestern University researchers

• ▪The Northwestern University study demonstrates that NIH's 2016 sex as a biological variable policy has not achieved its intended compliance goals.
• ▪The low 4% rate of papers discussing their rationale for sex as a biological variable approaches indicates researchers are not meaningfully engaging with the policy.

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