The NIH has published NOT-OD-15-102 Consideration of Sex as a Biological Variable in NIH-funded Research which informs us:
This notice focuses on NIH's expectation that scientists will account for the possible role of sex as a biological variable in vertebrate animal and human studies. Clarification of these expectations is reflected in plans by NIH's Office of Extramural Research (OER) to update application instructions and review questions; once approved by the Office of Management and Budget (OMB), these updates will take effect for applications submitted for the January 25, 2016, due date and thereafter.
Accounting for sex as a biological variable begins with the development of research questions and study design. It also includes data collection and analysis of results, as well as reporting of findings. Consideration of sex may be critical to the interpretation, validation, and generalizability of research findings. Adequate consideration of both sexes in experiments and disaggregation of data by sex allows for sex-based comparisons and may inform clinical interventions. Appropriate analysis and transparent reporting of data by sex may therefore enhance the rigor and applicability of preclinical biomedical research.4
NIH expects that sex as a biological variable will be factored into research designs, analyses, and reporting in vertebrate animal and human studies. Strong justification from the scientific literature, preliminary data, or other relevant considerations must be provided for applications proposing to study only one sex. Investigators are strongly encouraged to discuss these issues with NIH program staff prior to submission of applications.
Additional information is provided in a three page PDF overview:
Literature review. Consider and describe how sex and gender may influence the research question(s) at hand. Conduct a review of the human clinical literature and any relevant preclinical literature. If there are differences between males and females in previous preclinical or clinical studies, this would provide a strong rationale for building consideration of sex into the research design and analyses of data. The absence of previous study data in an area of research does not, by itself, constitute strong justification to study only one sex.
Very nice. So helpful. Look NIH, clearly this is going to be a place where applicants who do not wish to incorporate SABV into the design are going to seek a loophole. What would be helpful here would be a more assertive statement about what does and, most importantly does not, constitute a "strong justification to study only one sex". Uncontrolled, this will devolve back to the reviewers who are already failing (going by your highly effortful and high profile new initiative) to appropriately favor* SABV in research grant proposals. They are the ones that will decide that the tiniest fig leaf of excuse making is acceptable "justification" if you give them half a chance to do so. This part needs strengthening.
and later on in the document:
Single-sex studies. Applicants must provide strong justification for applications proposing to study only one sex. Such justification may include the study of sex-specific conditions or phenomena (e.g., ovarian or prostate cancer), acutely scarce resources (e.g., non-human primates), or investigations in which the study of one sex is scientifically appropriate. The absence of evidence regarding sex differences in an area of research does not constitute strong justification to study only one sex.
Sex-specific conditions or phenomena, check. Good. Will hard-to-breed mice constitute "acutely scarce resources"? Human drug abusers of various characteristics that make it hard to recruit female or male participants? The devil will be in the detail. But "scientifically appropriate"? Again, this holds open a big old loophole of escape. And a repeat of the absence-of-evidence statement. What does this mean? What are the limits on this strong justification? How are you going to get reviewers on board with this, instead of leaving them to accept any old excuse?
Research design, data analysis, and reporting.
....Where little or no sex-specific data is available, sex-specific hypotheses may not be possible, whereas previously observed sex differences may prompt sex-specific hypotheses.
Dude what? Are you kidding with this? We all know there must be a supported hypothesis in the research plan. And if there has not been any sex-differences research in the past, well, there are no hypotheses we can advance. And therefore, so sorry, we must avoid proposing anything that investigates SABV because the study section will kill us for lack of a clear hypothesis**. Another whoppingly huge escape clause for the SABV resistant PI.
Acknowledge limitations in the applicability of findings that may arise from the samples, methods, and analyses used, in the research plan as well as in progress reports and publications.
Emphasis added. HAHAHAHHAHHAA!!!! Yeah RIGHT! Every NIH Grant awardee who does not explicitly include SABV in a paper must make sure to add the caveat in the Discussion that their results cannot be extended to the other sex. Sure that's going to happen. Sure.
Finally, one for my peers who already conduct SABV research with regularity.
Researchers working with animal models should consider if and how the female estrous cycle is relevant for experimental design and analysis; it may be relevant for some research questions and not others
This one is pointed straight at the buzz saw of the sex-differences aficionado Stock Criticism of grant applications. One of the ways that sex-differences gets stamped out of research proposals is that the "real" experts start in on "YOU MUST DO THE SEX-COMPARISONS RIGHT AND AS WE HAVE DONE". This may include cycle synchronization, gonadectomy, pharmacologico-hormonal manipulations, endless groups, etc, etc, etc.
There is little tolerance from these people for "First, let's give it a go in female (or male) animals/cells/tissues and see what we turn up" exploratory fishing expeditions.
I would argue that tolerance for fishing expeditions is precisely what the NIH needs if they want to jumpstart real change. You have to make the barrier low and, especially in this day and age, of low cost. Demanding that it has to be SABV design 101eleventy at all times or it is not worth doing is going to motivate resistance. Resistance on the part of PIs doing their grant proposing and on the part of peers doing the grant reviewing.
I propose that a NIH policy of "Any old Third Aim that will engage in sex-differences comparisons is good enough and a total freebie for the first five years***" is what is necessary.
*oh yes, believe you me there are puh-lenty of investigators who propose SABV aspects in proposals and get it beat out of them at review.
***that may have to be slightly more formal