When is failure by an attending physician or surgeon to disclose material risks of a procedure or operation negligence?

The question of when failure by an attending physician or surgeon to disclose material risks of a procedure or operation is negligence was reviewed by Laskin C.J.C. in Reibl v. Hughes (1980), 1980 CanLII 23 (SCC), 114 D.L.R. (3d) 1 (S.C.C.). The standard is objective. The objective understanding is that of an average prudent person in the patient’s particular circumstances. Merely because medical evidence makes a recommended procedure reasonable does not mean that a reasonable person in the patient’s position will agree to that procedure. The patient’s concerns in particular circumstances must, however, be reasonably based.