Which description best matches an Impartial Witness in clinical trials?

• A. An independent body constituted of medical professionals and non-medical members, whose responsibility is to ensure the protection of rights, safety and well-being of human subjects involved in a trial and to provide public assurance by reviewing and approving/providing favorable opinion on, the trial protocol, the suitability of the investigator(s), facilities, and the methods and material to be used in obtaining and documenting informed consent of the trial subjects.
• B. A sponsor-appointed data manager
• C. A member of the regulatory authority
• D. An independent ethics committee that approves the protocol

Answer: (A)

An impartial witness is an independent observer whose role is to ensure that informed consent is obtained freely and properly documented, especially when a subject cannot read or write. The description that best matches this is an independent ethics committee (IEC/IRB) composed of medical professionals and non-medical members, whose job is to protect the rights, safety, and well-being of participants and to provide public assurance by reviewing and approving the trial protocol, the investigator’s qualifications, facilities, and the methods used to obtain and document informed consent. This framing emphasizes independence and protective oversight—the core idea behind the impartial witness. The other options describe roles that are not independent witnesses in the consent process (sponsor data manager, regulatory authority member) or are phrased more narrowly about protocol approval without the witnessing aspect.