Informed consent is one of the foundational ethical and legal requirements of research with human subjects. The Nuremberg Code, the Helsinki Declaration, the Belmont Report, the Common Rule and many other laws and codes require that research subjects (or the subject’s legal representative) make a voluntary, informed choice to participate in research.1 2 3 4 5 Informed consent is based on the moral principle of respect for autonomy, which holds that rational individuals have a right to make decisions and take actions that reflect their values and preferences.6 Whereas most guidelines and codes also require that informed consent be properly documented, informed consent is much more than signing a piece of paper: It is a continuous process of communication between the investigator and the research subject.7 Because the body of knowledge impacting a study frequently changes, subjects should receive information from investigators after they have enrolled in a study, such as significant new findings that may affect their decision to participate in research or clinically useful tests results.8 9 10 In large studies, some investigators use newsletters to update subjects on the progress of research and other developments.11

Most of the ongoing communications between investigators and subjects (or their representatives) involve little more than information sharing, without revisiting the decision to participate in research or signing any additional documents. Sometimes, however, it may be necessary for subjects to reaffirm their decision to participate, to re-consent, or to sign or re-sign a document.8 Re-consent can be defined as an action in which a subject (or representative) makes the decision to participate in research once again. Re-consent is different from reaffirming a commitment to participate in a study, because in re-consent one actually reconsiders the information necessary to make decision, whereas in reaffirmation one simply expresses …