Causation is the second element a plaintiff must prove in an Ontario medical malpractice claim, after standard of care and before damages. The plaintiff must show that the defendant’s negligence caused the injury, ordinarily by satisfying the “but for” test: but for the negligent act or omission, the injury would not have occurred. The Supreme Court of Canada confirmed this approach in Clements v Clements, 2012 SCC 32, [2012] 2 SCR 181, while recognizing a limited “material contribution to risk” exception in narrow circumstances.
In medical cases, causation is often the most contested element. A plaintiff who proves a clear breach of the standard of care may still lose at trial if expert evidence cannot bridge the gap between the breach and the injury. Lost-chance arguments, delayed-diagnosis fact patterns, and cases involving multiple potential causes raise some of the hardest causation questions in Canadian tort law.
Posts tagged Causation analyze how Ontario courts have approached these issues across obstetrical, oncology, emergency, and surgical fact patterns, including appellate decisions that shape how trial judges instruct themselves on the test.
A settlement on behalf of the family of a 39-year-old mother of two whose breast cancer was diagnosed too late after a missed opportunity to investigate.
September 2023 coverage in CP24 and the Brampton Guardian of the Thompson v Handler trial decision finding an ER physician negligent for the death of a 34-year-old mother.
A delayed-diagnosis cancer claim was dismissed at standard of care and causation, with a 40% contributory negligence finding for repeated failures to follow up.
Roughly 9% of strokes are initially misdiagnosed in the emergency setting. A practical guide to how stroke claims are investigated and proven in Ontario.
A trial judge dismissed a medical malpractice claim against two ER physicians, finding the standard of care was met and that earlier testing would not have changed the outcome.
A patient’s guide to medication errors in Ontario, including the common error patterns, the high-alert drugs, and what it takes to prove a malpractice claim.
A delayed cancer diagnosis can be the difference between life and death. A patient’s guide to the common causes and what it takes to prove a claim in Ontario.
Yes, but the harder question is whether your situation supports a viable claim. An honest threshold assessment for Ontario patients considering legal action.
A negligent stroke discharge that failed at causation. The Ontario Court of Appeal upheld the dismissal of the action, despite an admitted breach of standard of care.
I represented the plaintiff in this surgical malpractice case. The trial judge found a breach of the standard of care, but the claim failed at causation.
The Court of Appeal upholds the use of epidemiological evidence to infer causation across a class of patients harmed by a physician’s IPAC failures.
A missed diagnosis of compartment syndrome cost a patient her leg. The trial judge found the ER physician breached the standard of care.
Free, confidential consultations. Paul reviews every potential case personally and tells you honestly whether it merits investigation.