informed consent voluntary agreement in the light of relevant information, especially by a patient to a medical procedure. An example would be consent to a specific medical procedure by a competent adult patient who has an adequate understanding of all the relevant treatment options and their risks. It is widely held that both morality and law require that no medical procedures be performed on competent adults without their informed consent. This doctrine of informed consent has been featured in case laws since the 1950s, and has been a focus of much discussion in medical ethics. Underwritten by a concern to protect patients’ rights to self-determination and also by a concern with patients’ well-being, the doctrine was introduced in an attempt to delineate physicians’ duties to inform patients of the risks and benefits of medical alternatives and to obtain their consent to a particular course of treatment or diagnosis. Interpretation of the legitimate scope of the doctrine has focused on a variety of issues concerning what range of patients is competent to give consent and hence from which ones informed consent must be required; concerning how much, how detailed, and what sort of information must be given to patients to yield informed consent; and concerning what sorts of conditions are required to ensure both that there is proper understanding of the information and that consent is truly voluntary rather than unduly influenced by the institutional authority of the physician. See also ETHIC. J.R.M.