During Session 1 of Exploring the Common Rule, this question was posed: How do you balance finding a wide variety of participants with subset available locally that would otherwise qualify. Follow up: if you work in an area that is heavily dominated by one race (for example) but the results could affect many races.
This question goes beyond the scope of our course, but speaks to an important consideration: equitable selection of subjects. This concept comes into play for funders when they are determining research priorities, sponsors and research teams when they are designing studies (including inclusion/exclusion criteria and recruitment plans), institutions when they are deciding what research to prioritize and support, and IRBs when reviewing research. Currently, there is a lot of discussion about diversity, inclusion, and equity (DEI) and how that relates to equitable selection of subjects as well as sound research design and what the IRB's role is in this regard.
The FDA recently issued a draft for a potential requirement for Diversity Plan to Improve Enrollment of Participants in Clinical Trial, which provides helpful background information about why expanding the pool of research participants is important for improving health for everyone.
Additionally, the Multi-Regional Clinical Trials Center has done a lot of work on DEI in research, including creating some tools for researchers and IRBs. A great place to start is at https://mrctcenter.org/diversity-in-clinical-research/guidance/guidance-document/.