How far in advance of research participation can consent be obtained?
The HHS regulations at 45 CFR part 46 do not specify how far in advance of study entry a subject can provide consent. The amount of time required by a subject to make a decision would presumably depend on the nature of the study, taking into account, among other factors, the degree of risk, potential benefits, alternatives, and desire to consult with family members or others. However, if a prolonged period of time elapses from the date of consent to the date of entry into the studyeven if there have been no changes in the study design or no new significant findings affecting the studyit might be prudent to review the information contained in the consent form with the subject prior to initiating any research procedures with the subject.
