Chester v Afshar

A doctor who negligently fails to warn a patient of an inherent risk may be treated as having caused the resulting injury where the patient would otherwise have declined that operation at that time and the undisclosed risk materialises. The patient need not prove that she would never have undergone comparable surgery.

The ordinary “but for” test remains necessary but may not be sufficient. Liability extends to the kind of harm against which the duty to warn was intended to protect. The possibility that the patient would later have undergone surgery, or suffered the same injury, concerns the assessment of damages where the evidence does not show that the injury would probably have occurred in any event.

The claimant underwent elective spinal surgery performed by the defendant neurosurgeon. The operation was performed without negligence, but an inherent risk of nerve damage materialised and caused substantial disability. The trial judge found that the defendant had negligently failed to warn her of that risk. Properly warned, she would not have undergone the operation on that date and would have sought further opinions.

The defendant appealed from the High Court order giving judgment for damages to be assessed. He challenged the warning finding, causation and the adequacy of the pleading. The central issue was whether the claimant also had to prove that she would never have undergone comparable surgery carrying the same or similar risk.

1. Appeal dismissed. The court gave a joint judgment to which all three members contributed. It upheld the finding that the defendant had negligently failed to warn the claimant of the small but serious risk of nerve damage and paralysis. The trial judge had compelling reasons for accepting her evidence, and there was no proper basis for appellate interference.

2. The claimant bore the burden of proving causation. If she would have undergone the same operation at the same time despite a proper warning, the omission would have made no difference. Conversely, proof that she would never have undergone the procedure would plainly establish causation. The present case fell between those situations because she would have postponed the operation and sought further advice, although her eventual course could not be predicted.

3. It was sufficient that a proper warning would have prevented the operation from occurring when and in the circumstances in which it did, and that the very risk requiring disclosure then materialised. The defendant thereby exposed the claimant to an operation she would not otherwise have undergone then and there. The court adopted the conclusion of the majority in Chappel v Hart [1998] 72 Australian Law Journal Reports 1344.

4. The “but for” test was necessary but not invariably sufficient. A doctor would not be responsible for an unrelated coincidence merely because proper advice would have kept the patient away from the operating theatre. Here, however, the injury was the precise inherent risk about which the claimant had sought information and against which the duty to warn protected her autonomous choice.

5. The claimant did not have to prove that she would never have undergone similar surgery. Whether she probably would later have undergone an operation carrying the same risk, and whether that risk probably would then have materialised, remained open for determination when damages were assessed. Those matters could affect the period or amount of loss without defeating the causal connection.

6. The pleading adequately alleged that the claimant had lost the opportunity to reflect and seek further opinions and would not have consented to the operation actually performed. The trial judge had also been entitled to refuse a late attempt to strike out that issue.

1. Court of Appeal: By a joint judgment, dismissed the defendant’s appeal, refused permission to challenge the finding that no adequate warning had been given, and upheld judgment for the claimant.
2. High Court, Queen’s Bench Division: His Honour Judge Robert Taylor found that the operation had not been negligently performed but that the defendant had negligently failed to warn of the risk of nerve damage and paralysis. He held that the failure caused the injury and gave judgment for damages to be assessed.