What is the composition of an IRB?

• A. at least 5 members; diversity; at least one scientific member; at least one non-scientific; at least one not affiliated with or related to the institution
• B. exactly 3 members all scientists
• C. 12 members all from the sponsor's employees
• D. 8 members all community advocates

Answer: (A)

Understanding how an IRB is formed helps explain why this composition is required. Federal rules require an IRB to have at least five members with diverse backgrounds to ensure a balanced and objective review of research involving human subjects. Crucially, there must be members who bring scientific or medical expertise, as well as members who come from non-scientific backgrounds to represent community and participant perspectives. In addition, at least one member must be unaffiliated with the institution to help prevent conflicts of interest and promote independent judgment.

This setup—minimum size, scientific and non-scientific representation, plus an unaffiliated member—ensures that risks, benefits, consent processes, and protections for participants are evaluated from multiple angles, not just a technical or institutional viewpoint. The other configurations described would miss one or more of these requirements: they might not meet the minimum number, lack a non-scientific or unaffiliated perspective, or rely entirely on affiliated or sponsor personnel, which would compromise independence and broad oversight.