The informed consent form is a written description of the nature and purpose of the trial. This document includes an explanation of the nature of randomization and includes a description of the benefits, foreseeable risks, discomforts and potential side effects of participating in the study. The consent form should inform the patient that he or she has the right to withdraw from the study at any time without prejudice, and that alternative treatments are available, should he or she decide not to participate in the study. The consent form is presented to the patient, preferably in the presence of an impartial witness, by the investigator or a qualified delegate; sufficient time must be allowed for the patient to consider the information and to ask questions.

This form is an acknowledgment that specific information has been given; it is never proof that the subject has been fully informed. It does not indicate the degree of comprehension or autonomy of the patient. Even if the informed consent is for the protection of the investigator and the patient, it has no legal power in North America.