Subjects with limited comprehension require special protection. This group includes infants and young children, as well as individuals who are mentally impaired, have Alzheimer's disease, are comatose, etc.
Subjects with limited comprehension are not considered to be capable of providing informed consent. If they are to participate in research, an authorized third-party (parent, guardian, next of kin, etc.) should be appointed to represent the subject's interests.
- The third parties should be those who are most likely to understand the incompetent subject's situation and to act in that person's best interest.
- Investigators should inform and communicate with the subject, as well as the third party, as much as possible.
- Whenever possible, communications should occur immediately prior to undertaking the investigation, to increase the likelihood that the subject will understand and remember what he/she has agreed to.
- Whenever possible, informed consent documents should be signed by both the subject and the authorized third party.
- The person authorized to act on behalf of the subject should be able to observe the research as it proceeds. This person should be aware that he/she can withdraw the subject from the investigation at any time, if such action appears in the subject's best interest.