What is the legal test for a surgeon to determine whether a patient’s hypothetical choice to refuse treatment should be based solely on the testimony of the patient at trial?

The legal test for this analysis is clearly established. In Reibl v. Hughes, 1980 CanLII 23 (SCC), [1980] 2 S.C.R. 880, 114 D.L.R. (3d) 1, Laskin C.J.C. considered the question of whether a patient’s hypothetical choice to engage in or refuse treatment should be based strictly on the testimony of the patient at trial: ... Merely because medical evidence establishes the reasonableness of a recommended operation does not mean that a reasonable person in the patient's position would necessarily agree to it, if proper disclosure had been made of the risks attendant upon it, balanced by those against it. The patient's particular situation and the degree to which the risks of surgery or no surgery are balanced would reduce the force, on an objective appraisal, of the surgeon's recommendation. Admittedly, if the risk of foregoing the surgery would be considerably graver to a patient than the risks attendant upon it, the objective standard would favour exoneration of the surgeon who has not made the required disclosure. ... In saying that the test is based on the decision that a reasonable person in the patient's position would have made, I should make it clear that the patient's particular concerns must also be reasonably based ... In short, although account must be taken of a patient's particular position, a position which will vary with the patient, it must be objectively assessed in terms of reasonableness.

Cory J. succinctly described this ‘objective/subjective’ assessment as “... whether a reasonable person in the circumstances of the plaintiff would have consented to the proposed treatment if all the risks had been disclosed.” (Arndt v. Smith, 1997 CanLII 360 (SCC), [1997] 2 S.C.R. 539 at 554, 148 D.L.R. (4th) 48). 2. Evidence