Inclusion of sex and gender in biomedical research: survey of clinical research proposed at the University of Pennsylvania

Anne Freeman, Patrick Stanko, Lily N. Berkowitz, Neanta Parnell, Anastasia Zuppe, Tracy L. Bale, Tracy Ziolek, C. Neill Epperson

The 2015 National Institutes of Health (NIH) policy that sex be considered as a biological variable (SABV) is now a critical part of the peer-review process for NIH funding as well as publication in several high-impact scientific journals. We sought to determine the degree to which biomedical researchers at the University of Pennsylvania already consider SABV or gender in their research. We reviewed 240 research protocols approved by the University of Pennsylvania Investigational Review Board (IRB) consecutively submitted between January and July 2016. Each protocol was searched for the terms sex, gender, male, female, man, and woman and justifications related to the population under study. A PubMed search was conducted to determine the current state of knowledge regarding potential sex and/or gender differences with respect to protocol topic. Data were summarized using descriptive statistics. Of the 165 (68.8%) protocols that included one of the search terms, only 24 (14.5%) provided justification for the choice of the sex/gender of the population studied. Sixty-three percent (n = 151) of the protocols focused on topics for which the extant literature supports at least a moderate degree of sex/gender differences in some aspect of the disorder/condition being studied. Of these, only three (2.0%) indicated that the investigator would consider sex or gender impact on their primary outcomes. Review of a subset of IRB protocols submitted at a major research institution suggests that very few investigators are considering sex or gender as important variables in their clinical research at the stage of protocol development. IRBs are in an excellent position to encourage investigators to consider SABV and gender in order to enhance the rigor of research design, maximize the importance of the resulting knowledge, and ensure that subject selection is equitable. These findings serve as the basis for developing an intervention at the level of IRB protocol development and submission that will promote consideration of SABV and/or gender, factors with critical import to patient safety and efficacy of interventions.