What is the test for disclosure in medical malpractice?

27. Reibl v. Hughes dealt also with the determination of whether a risk was a material one or a special or unusual one and discussed the significance of medical evidence on that question and the significance of the personal circumstances of the patient in deciding whether the risk should be regarded as material or as special or unusual or as neither. The decision emphasized that the practice of the medical profession cannot alone decide whether a risk is material or special or unusual. The entitlement of the patient to know the full facts about risks and to make a personal assessment of those facts in the light of the patient's own view of his or her own circumstances is a major determinant of whether there has been the disclosure required by law.

28. I have mentioned the questions of law considered in Hopp v. Lepp and Reibl v. Hughes in order to give a context to the final legal question discussed in Reibl v. Hughes, namely the question of proof of causation. Was the loss suffered by the patient caused by the failure of disclosure by the doctor, or would it have occurred even if there had been full and proper disclosure?