Inclusion of both sexes in research design - Call for input

In April 2022, we asked for feedback on the new MRC expectations on the inclusion of sex in experimental design of studies involving animals, tissues, and cells. We also asked what MRC could do to aid researchers in implementing these requirements.

We received 91 responses from researchers and research staff, with many constructive and detailed suggestions. We also received a written submission from the Academy of Medical Science, on behalf of their fellows.

We were pleased that many were already using both sexes in their experiments or were ready to begin doing so (32% and 5% of respondents, respectively). We recognise that many (57%), even though they were very often supportive in principle, felt barriers existed to implementing this in their research.

One of the most commonly mentioned concerns was a likely increase in grant costs. Respondents sought clarity from MRC as to how this would be handled. Ensuring animal welfare standards and the logistics of single housing male animals were also mentioned as barriers.

Roughly a third of respondents had questions about the changes, particularly around:

• When the new expectation would begin to apply and how compliance would be ensured
• How and when MRC would grant exceptions for single sex studies
• How MRC would handle grants where costs were significantly increased due to using both sexes of animal

The support from MRC that was identified as being most helpful was:

• Advice from MRC Head Office about applications
• Training in statistical design and analysis
• Written guidance
• Case studies or worked examples

As a result of this feedback, we have been working to make more information available about the upcoming change and to ensure the research community receives the necessary support. We have:

• Updated our Guidance for Applicants with details about how to comply with these new expectations
• Made it clear that there is no retrospective application of this requirement for grants that have already been awarded
• Clarified that the requirement of including both sexes does not mean ‘balancing’ or using equal numbers of both sexes, as for many experiments this would result in unnecessary use of animals, but including both sexes as appropriate for the experimental design 
• Made the cases where MRC will consider single sex studies clearer both on our website and in our Guidance for Applicants
• Planned a webinar for applicants together with NC3Rs to be held on 21 July 2022, in which animal handling and statistical design will be discussed, and applicants can ask questions
• Made it clearer on our website that there is no cap on MRC awards, and researchers should submit grant costings based on the cost of performing the work, and justified by the importance and potential of the work

In the coming months, we will:

• Update our guidance to Peer Reviewers to ensure proposals submitted to the deadlines starting from September 2022 are reviewed in accordance with the new requirements
• Develop case studies to show the level of information that would be required in applications, including examples of where single sex studies would be appropriate
• Ensure that MRC Programme Managers are available to support applicants that have further questions
• Look into what other support we can provide