What constitutes informed consent in medical malpractice cases?

The notion of informed consent relates, in the vast majority of cases, to a cause of action in negligence rather than battery but may be said to have evolved from the notion of battery. A battery occurs when there is “an unprivileged, unconsented to and intentional invasion of [a person’s] bodily integrity”: Reibl v. Hughes (1980), 1980 CanLII 23 (SCC), 114 D.L.R. (3d) 1 at 10 (S.C.C.). With respect to medical treatment, a battery occurs when there is either no consent to treatment at all, or that consent is obtained via fraud or misrepresentation. On the other hand, a failure to disclose the attendant risks of a procedure relates to an informed choice of submitting to or refusing recommended and appropriate treatment … [and] arises as a breach of an anterior duty of due care, comparable in legal obligation to the duty of due care in carrying out the particular treatment to which the patient has consented: Reibl v. Hughes, supra at 11.