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

Conduct is negligent if it creates an objectively unreasonable risk of harm. 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 harm. A statutory breach does not automatically give rise to civil liability; although it can be some evidence of negligence. One cannot avoid the underlying obligation of reasonable care simply by discharging statutory duties. Statutory standards can be highly relevant to the assessment of reasonable conduct and may render reasonable an act or omission which would otherwise appear to be negligent: Ryan v. Victoria (City), 1999 CanLII 706 (SCC), [1999] 1 S.C.R. 201 at paras. 28-29.