Admitted Error, No Liability: The Importance Of Causation In Medical Negligence

Medical negligence cases are often viewed through the lens of whether a healthcare provider made a mistake or not. However, simply proving that a medical provider breached the requisite standard of care is not, alone, enough. A plaintiff must also establish that said breach caused the damages claimed.

Causation in the legal sense requires that a plaintiff prove that the medical provider’s negligence (whether that be something the provider did or failed to do) likely caused or materially contributed to the injury complained of.

The Importance of Causation

The Ontario Court decision in Johnson v. Lakeridge Health Corporation, 2023 ONSC 2575 (upheld by the Court of Appeal in 2024) demonstrates the importance of establishing causation.

In Johnson v. Lakeridge Health Corporation, the plaintiff Mr. Johnson suffered a stroke. During his hospitalization, diagnostic testing identified an underlying condition. However, the treating physician discharged Mr. Johnson without reviewing the imaging results. Mr. Johnson unfortunately suffered a second more severe stroke about a week later, leaving him with lasting impairments.

At trial, the treating physician admitted that she was negligent in failing to review the imaging results before discharging Mr. Johnson. However, the treating physician argued that the plaintiffs had not proven causation.

The parties relied heavily on competing expert evidence. The plaintiffs argued that had the imaging been reviewed before discharge, Mr. Johnson would have received anticoagulation treatment earlier and the second stroke would likely have been prevented. The defence expert’s evidence was that the available medical literature did not support a conclusion that earlier anticoagulation would have necessarily changed the outcome.

Despite the fact that the physician had acknowledged a breach of the standard of care, the Court ultimately preferred the defence’s expert evidence. The trial judge’s decision in fact quotes the defence’s expert, who stated: “[E]very time someone has a stroke, it’s heartbreaking. And the reality is our current available medications are just not foolproof. Unfortunately, our treatments do not prevent all strokes.”

Due to plaintiffs’ failure to establish causation, the action was dismissed.

On appeal, the Court of Appeal found no error with the trial judge’s analysis and the appeal was dismissed.

Conclusion

Johnson v. Lakeridge Health Corporation is an important reminder that a breach of standard of care – even if admitted – is not enough to establish liability. A plaintiff must still establish on a balance of probabilities that the negligence caused their alleged damages.

Medical negligence cases frequently turn on nuanced medical evidence and expert opinion. For defendants and insurers, this case highlights the importance of having skilled and experienced legal counsel who can evaluate and parse out the issues that may ultimately determine the outcome of the litigation.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.