News: NIH to Balance Sex in Cell and Animal Studies

In 1993, the NIH Revitalization Act required the inclusion of women in NIH-funded clinical research.

Today, just over half of NIH-funded clinical-research participants are women. We know much more about the role of sex and gender in medicine, such as that low-dose aspirin has different preventive effects in women and men, and that drugs such as zolpidem, used to treat insomnia, require different dosing in women and men.

There has not been a corresponding revolution in experimental design and analyses in cell and animal research — despite multiple calls to action. Publications often continue to neglect sex-based considerations and analyses in preclinical studies. Reviewers, for the most part, are not attuned to this failure. The over-reliance on male animals and cells in preclinical research obscures key sex differences that could guide clinical studies. And it might be harmful: women experience higher rates of adverse drug reactions than men do. Furthermore, inadequate inclusion of female cells and animals in experiments and inadequate analysis of data by sex may well contribute to the troubling rise of irreproducibility in preclinical biomedical research, which the NIH is now actively working to address….

The NIH is now developing policies that require applicants to report their plans for the balance of male and female cells and animals in preclinical studies in all future applications, unless sex-specific inclusion is unwarranted, based on rigorously defined exceptions. These policies will be rolled out in phases beginning in October 2014, with parallel changes in review activities and requirements. Because our goal is to transform how science is done, the first step will be the development and delivery of training modules and detailed policy informed by ongoing data analysis. As part of its initiative to enhance rigour, the NIH plans to disseminate training on experimental design for NIH staff, trainees and grantees. Evaluation of sex differences will be included in these modules.

Read the full comment in Nature from Francis S. Collins, Director of the National Institutes of Health, and Janine A. Clayton, Director of the NIH Office of Research on Women’s Health.

Further media coverage of this issue.