We as a scientific community have made major progress toward balancing the number of men and women who volunteer as participants in biomedical research studies; in fact, women now account for roughly half of the participants in NIH-funded clinical trials. However, we haven’t seen a similar pattern in the pre-clinical research involving animals and cells. As described in a May Nature article by NIH Director Francis Collins and NIH Associate Director for Research on Women’s Health Janine Clayton, research studies using animal models frequently include only males, and studies using cell models often do not consider the sex of the individual from which the cells were obtained. And, even if a study design includes male and female specimens or animals, the resulting data may not be analyzed or reported in a way that helps us understand how sex, as a biological research variable, influences the findings.
Sex is a critical variable when trying to understand the biological and behavioral systems that fundamentally shape human health. As such, it also is a critical element to be considered when designing rigorous preclinical research experiments that inform human studies. Thus, as announced in May, NIH intends to develop and implement policies requiring NIH applicants to consider sex as a variable in biomedical research involving animals and cells. As I described in a blog post earlier this year, NIH will be taking a phased approach to this initiative.
We are starting by gathering input from you. So today we announced a formal request for information (RFI) to get input from the research community, and others. As described in the RFI, we want to hear your thoughts on several topics – for example, whether consideration of sex as a biological variable is an issue affecting the reproducibility of research findings; what areas of science or phases of research present the greatest needs or opportunities for understanding data disaggregated by sex; and the major challenges to considering sex as a biological variable in research. We also want to hear your ideas about how NIH can facilitate this aspect of your research, and any other feedback related to NIH’s development of policies for considering sex as a biological variable in research involving animals, tissues, or cells.
Your input will help us shape policies that enhance the rigor of biomedical research, and in turn strengthen the foundation of clinical research.
As always, you are welcome to weigh in on the comment section of the blog, but please refer to the RFI for information on how to submit formal feedback to NIH. We look forward to hearing from you! I also hope you will stay tuned this fall for more information from NIH on how we are working to strengthen science by studying sex.