Chester -v- Afshar HL 14 October 2004

Lord Bingham of Cornhill, Lord Steyn, Lord Hoffmachn, Lord Hope of Craighead and Lord Walker of Gestingthorpe

Miss Chester suffered episodes of lower back pain for six years from 1988. Following a particularly painful episode in 1994 Miss Chester was referred to Mr Afshar, a consultant neurosurgeon. Mr Afshar advised Miss Chester to undergo an elective lumbar surgical procedure. This procedure entails a 1% - 2% chance of serious neurological damage arising from the operation. In breach of the common law duty of care Mr Afshar failed to advise Miss Chester of this risk. Miss Chester suffered serious neurological damage as a result of the operation.

Mr Afshar had not been negligent in performing the operation and had not increased the inherent risks involved. The issue in question therefore was whether the injury would have occurred had Miss Chester been fully informed of the risks involved.

The Judge was unable to find whether Miss Chester would have consented to the operation had she been fully informed. However he held that had she agreed to surgery at a later date the risk (ie 1% - 2%) would have been the same and it would therefore be probable that she would have sustained neurological damage. The Judge found that the Claimant had established a causal link between the breach and the injury and found the defendant liable for same. The Court of Appeal upheld this decision.

The case proceeded before the House of Lords in October 2004. Counsel for the surgeon now argued that in order to establish causation in this type of case the patient must prove that she would not have consented to run the relevant risk then and there, and that she would not, ultimately, have consented to run the relevant risk.

LORD BINGHAM OF CORNHILL and LORD HOFFMAN issued dissenting opinions on this case. They argued that the burden is on the claimant to prove that the defendant's breach of duty caused the damage. Miss Chester therefore had to prove that had she been fully informed of the risks she would not have had the operation. The judge however made no such finding nor was he invited to do so by the claimant. The claimant argued that as a matter of law it was sufficient that she would not have had the operation at that time or by that surgeon, even though the risk would have been precisely the same. They allowed the appeal on the basis that Miss Chester had failed to prove that Mr Afshar's breach of duty caused her loss.

LORD HOPE OF CRAIGHEAD, LORD STEYN and LORD WALKER OF GESTINGTHORPE dismissed the appeal. Although they agreed with the dissenting judges that Miss Chester had failed to prove that she would not have undergone the surgery had she been fully informed and therefore could not succeed on conventional causation principles. However they argued that in such cases a modest departure from traditional causation principles should be granted. They ruled that the causation issue should be addressed by reference to the scope of the defendant's duty to warn patients of any risks involved in a proposed procedure; that duty was closely connected with the need for the patient's consent and was central to her right to exercise an informed choice as to whether and, if so, when and from whom to receive treatment. The function of the law was to protect the patient's right to choose. Accordingly the House of Lords dismissed the appeal ruling that the test of causation had been satisfied on policy grounds.