Chester v Afshar [2004] UKHL 41 (14 October 2004)

A patient suffered paralysis from a small, undisclosed risk of spinal surgery. The surgeon's failure to warn breached his duty of care. The court found for the patient, modifying causation rules to vindicate her right to informed consent and make an informed choice.

Facts

The claimant, Miss Chester, suffered from long-standing lower back pain. She was referred to the defendant, Mr Afshar, an experienced neurosurgeon. Mr Afshar advised her to undergo elective spinal surgery. The procedure carried a small but unavoidable risk of serious neurological damage (cauda equina syndrome), estimated at 1-2%, even if performed with due care and skill. Mr Afshar failed to warn Miss Chester of this specific risk. The operation was performed competently by Mr Afshar, but unfortunately, the risk materialised, and Miss Chester suffered severe paralysis. The trial judge found that had she been warned, she would not have consented to the surgery on that particular day. She would have sought further advice before deciding, although she could not say she would have refused the surgery indefinitely.

Issues

The central legal issue before the House of Lords was causation. The claimant accepted that the surgery was not performed negligently and that the risk was inherent in the procedure. Given that she might have had the operation on a later date (at which point the same 1-2% risk would have existed), could the surgeon’s failure to warn be legally considered the cause of her injury? The key question was whether a departure from the traditional ‘but for’ test of causation was justified to provide a remedy for the breach of the surgeon’s duty to inform the patient of significant risks.

Judgment

By a 3-2 majority, the House of Lords dismissed the appeal, finding in favour of the claimant. The court held that to deny liability would render the surgeon’s duty to warn of risks meaningless.

The Majority View

Lords Steyn, Hope, and Walker held that a limited, policy-based exception to traditional causation principles was necessary to vindicate the patient’s right to autonomy and informed consent. They reasoned that the duty to warn exists specifically to allow a patient to make an informed choice. If a breach of this duty, which leads directly to the injury that the patient should have been warned about, results in no remedy, the duty itself becomes hollow.

Lord Steyn stated:

The patient’s right to be appropriately warned is an important right, which is entitled to the protection of the law… It would be a hollow victory for the claimant… if the law treated the surgeon’s duty as fulfilled even though the claimant was wrongfully deprived of the opportunity to make an informed choice and was injured as a result.

Lord Hope of Craighead emphasised the purpose of the duty:

To leave the patient without a remedy, as Lord Bingham and Lord Hoffmann suggest, would be to render the duty worthless in the eyes of the patient for whom it was conceived. It would be a betrayal of the trust which the patient had placed in the surgeon.

The majority concluded that the causal link was established because the surgeon’s breach of duty led to the claimant consenting to an operation she would not have undergone at that time, and the injury was the direct result of that operation.

The Dissenting View

Lords Bingham and Hoffmann dissented, arguing for a strict application of causation principles. They argued that the injury was caused by the inherent risk of the surgery, not by the failure to warn. The failure to warn did not increase the risk, but merely changed the time at which the claimant was exposed to it. As the claimant would have been exposed to the exact same risk had the surgery occurred at a later date, the ‘but for’ test was not satisfied.

Lord Bingham stated:

It is not correct that unless this claim is allowed the surgeon’s duty to warn will be drained of its content. A surgeon who fails to warn a patient of the risks of a recommended procedure will be liable in damages if the patient, duly warned, would have refused the procedure and so escaped the injury. If, duly warned, the patient would have consented to the procedure, the surgeon will not be liable in damages for the materialisation of a risk of which the patient was not warned, but the surgeon may be sanctioned by his professional body for his professional default.

Lord Hoffmann argued that creating an exception to causation principles for this type of case was unprincipled and would distort the law.

Implications

The decision in Chester v Afshar is a landmark case in medical negligence. It establishes a modified test for causation where a doctor’s breach of duty is a failure to warn of a risk which then materialises. The case places a high value on the principle of patient autonomy and the right to informed consent. It confirms that the purpose of the duty to warn is not merely to avoid a bad outcome, but to allow the patient to make an an informed choice. By allowing the claim to succeed without strict proof of ‘but for’ causation, the House of Lords created a narrow, policy-driven exception to ensure that the duty to warn remains a potent and enforceable legal obligation.

Verdict: The appeal by the defendant surgeon was dismissed, with the House of Lords upholding the Court of Appeal’s decision in favour of the claimant.

Source: Chester v. Afshar [2004] UKHL 41 (14 October 2004)