What is the test for negligent conduct in the context of medical malpractice cases?

In Ryan v. Victoria (City), 1999 CanLII 706 (SCC), [1999] 1 S.C.R. 201 at para. 28, 168 D.L.R. (4th) 513, negligent conduct was defined as follows: Conduct is negligent if it creates an objectively unreasonable risk of harm. To avoid liability, a person must exercise the standard of care that would be expected of an ordinary, reasonable and prudent person in the same circumstances. The measure of what is reasonable depends on the facts of each case, including the likelihood of a known or foreseeable harm, the gravity of that harm, and the burden or cost which would be incurred to prevent the injury.