Chester (Respondent) v. Afshar (Appellants)

Where a surgeon negligently fails to warn a patient of a small but established risk inherent in proposed surgery, causation may exceptionally be established if the patient would have postponed the operation and the very risk materialises during it. The patient need not prove that proper warning would have led her to refuse that operation for all time.

This narrow departure from conventional causation protects the patient's autonomy. It applies where the injury falls within the scope and focus of the duty to warn. It does not make a surgeon generally liable for every consequence of non-negligent surgery.

The respondent suffered serious neurological injury after elective spinal surgery performed skilfully by the appellant neurosurgeon. The judge rejected her allegation of negligent surgery but found that the surgeon had failed to warn her of the small, unavoidable risk of nerve damage and paralysis. He also found that, if warned, she would not have undergone the operation when she did and would have sought further opinions. He did not find that she would never have undergone surgery.

The Court of Appeal dismissed the surgeon's appeal: [2002] EWCA Civ 724; [2003] QB 356. The central issue before the House was whether causation could be established although the risk would have been substantially the same whenever and by whomever the surgery was performed.

1. By a majority, the appeal was dismissed. Lord Steyn and Lord Hope held that the patient's injury was legally caused by the surgeon's negligent failure to warn. Lord Walker agreed with both speeches. Lord Bingham and Lord Hoffmann dissented.
2. Per Lord Hope, the duty to warn exists so that a patient can decide whether, when and by whom to undergo treatment. Its scope encompasses the consequences of the risks about which the patient ought to be informed. The choice remains the patient's, including the choice to defer a decision and seek further advice.
3. Per Lord Hope, conventional causation principles did not provide a complete solution. The failure to warn neither created nor increased the inherent operative risk. Nonetheless, the injury occurred during the very operation proposed by the surgeon, was the very injury about which warning was required and lay within the scope of the duty. Policy therefore required the normal approach to causation to be modified in these unusual circumstances.
4. Per Lord Steyn, the patient's autonomy and dignity justified a narrow and modest departure from traditional causation principles. The conclusion did not establish general strict liability for surgery. It vindicated the right to make an informed choice where the failure to warn resulted in the occurrence of the very risk that should have been disclosed.
5. Per Lord Walker, bare “but for” causation was reinforced by the close connection between the injury and the focus of the duty to warn. Requiring an honest patient to prove that she would never have submitted to surgery could drain that important duty of practical content.
6. Lord Bingham and Lord Hoffmann dissented. On ordinary principles, they considered that the claimant had to prove that warning would have led her to avoid or reduce the risk, rather than merely postpone surgery or change surgeon where the risk remained the same. They would have allowed the appeal.

1. House of Lords: By a majority of 3–2, dismissed the surgeon's appeal and affirmed liability.
2. Court of Appeal: Dismissed the surgeon's appeal from the finding of liability: [2002] EWCA Civ 724; [2003] QB 356.
3. Trial: Judge Robert Taylor rejected the allegation of negligent performance of the operation but held the surgeon liable for negligently failing to warn of the inherent risk. Assessment of damages was adjourned pending determination of liability.