What is the test for a finding of no negligence in a medical malpractice case?

A somewhat similar approach applies to customary practices. Lord Alness in McDaniel v. Vancouver Gen. Hosp., 1934 CanLII 276 (UK JCPC), [1934] 3 W.W.R. 619, [1934] 4 D.L.R. 593 at 597 (P.C.), overstated the matter when he said, "a defendant charged with negligence can clear his feet if he shows that he has acted in accord with general and approved practice" but the cases do show that conformance with a generally accepted practice usually results in a finding of no negligence. Employing similar reasoning "failure to adopt the general practice is often the strongest possible indication of want of care": Fleming, The Law of Torts, 5th ed. (1977), p. 118.