Causation effect

A recent clinical negligence case made all professionals sit up and take notice. But lawyers need not worry – the ruling does not apply to them. By Peter Causton

Professionals of all kinds will have breathed a collective sigh of relief following the decision in Paul Davison & Taylor v White on 18 November 2004, where the Court of Appeal refused to follow Chester v Afshar (2004), a case that appeared to have swept away long-established rules of causation and increased the remit of professional negligence claims.

Chester v Afshar was a high-profile medical negligence case in the House of Lords concerning a patient suffering from repeated back pain. She was advised and underwent surgery to alleviate her condition. However, she was not warned about an unavoidable risk (1-2 per cent) that the treatment would have a seriously adverse result, which unfortunately did occur.

The patient argued that, had she been warned, the operation may not have taken place at that time or with that surgeon, and that as the risk was so low the outcome may have been different if either of these had changed. It was ruled that this was sufficient for causation purposes despite the fact that the surgeon had only exposed the patient to a risk to which she was already exposed, ie she would have gone ahead in any event.

The Lords recognised that the central question was whether the conventional approach to causation in negligence actions, applying the ‘but for’ causation test, should be varied in these circumstances. The majority supported the patient’s argument, ruling that the surgeon had breached the duty of care to the patient, regardless of the fact that she might have proceeded in any event. The patient was entitled to compensation on the basis that, had she been warned, then the future would have happened differently, even if the outcome remained the same.

The Lords recognised that a mechanical application of the ‘but for’ test could be too restrictive or expansive in certain circumstances and produce unjust outcomes. It could result, for example, in a person claiming successfully that, but for the delay to their journey, they would not have boarded The Titanic. Equally it may mean that a person was unable to claim that an unidentifiable exposure to asbestos had caused mesothelioma (whereas the court had permitted a claim in these circumstances in Fairchild (2003)).

Lord Hoffmann was a dissenting voice, arguing that the question was whether the patient would have taken the opportunity to avoid or reduce the risk, not whether she would have changed the scenario in some irrelevant detail. It was as illogical as saying that if a gambler in a casino had been told that the odds on number seven coming up at roulette were only one in 37, he would have gone to another casino or come back another time. Lord Hoffmann did not consider that a special rule should be created whereby doctors who failed to warn patients of risks should be made insurers of those risks.

Lord Hope considered that an appeal to common sense alone would not provide a satisfactory answer to the causation problem. He said it was no more reliable a guide to the right answer than surveying the views of travellers on the Piccadilly Line. Ultimately the patient was successful in her claim, and weighing heavily in her favour was undoubtedly the important principle of informed consent, enshrined in surgeons’ guidance, and the view that ‘medical paternalism’ no longer rules. The decision indicated that it was unjust for a patient to be left without a remedy for an injury suffered as a result of an operation where the risks were not outlined.


This decision opened a debate among other professionals as to whether claimants could bring claims against them using the same ‘back to the future’ principle. The issue was revisited by the Court of Appeal in Paul Davison & Taylor v White, a solicitors’ negligence case. In this case, the defendant solicitors had been negligent in their conduct of a possession action. The claimant’s father was a secure tenant of a housing association property. Following his father’s death the association issued a notice seeking possession and a notice to quit. The solicitors acted in the possession proceedings, in which the claimant made a counterclaim against the association seeking to exercise a right to buy the property. The association applied to amend the claim on the basis that the tenancy had been terminated by the notice to quit. Despite being advised that he had no defence, the claimant contested the application and lost, but surprisingly the court ordered the association to pay his costs of the proceedings to date. The claimant later brought a claim against his solicitors for failing to advise him at the outset of the effect of the notice to quit, causing him to proceed with the litigation on an erroneous basis.

In this instance, the judge found that the evidence given by the claimant to demonstrate that he would have acted differently and not proceeded with litigation contradicted everything that was written or said in the case. He ruled that the defendant would not have given up possession of his property and that he would have continued to defend the indefensible. The Court of Appeal assumed breach of duty, without deciding it, as it considered that the claimant could not establish any causal link between the negligence and any resulting loss.

Lord Justice Ward considered Chester v Afshar to be an “unusual case” of medical negligence, where the departure from traditional causation principles was necessary for policy reasons and in the interests of justice. In his view, the traditional approach to causation produced a just result in this case. Lady Justice Arden agreed, stating that, in her judgment, Chester v Afshar did not “establish a new general rule on causation”, but that in exceptional circumstances she recognised that the rules regarding causation may be modified on policy grounds. She also referred to the principle of informed consent to medical procedures as having special importance in law and to widespread ethical concerns on the issue of patient consent. She found that there were no policy considerations in this case and, if there were, that it would still be difficult to distinguish it from any other case of professional negligence on the part of a lawyer or accountant. She considered that none of the long-established authorities on causation had been overruled and that it would not be right for the Court to apply Chester v Afshar in preference to the traditional principles of causation.

Hard cases make bad law and it is easy to see why Chester v Afshar, in which the sympathies of the court were firmly with the patient, was a hard case. Following Paul Davison & Taylor v White, the balance appears to have been redressed and the principles elucidated in Chester v Afshar are likely to be restricted to the clinical negligence arena and will not be applied widely to all negligence claims against professionals.

Although other claimants may still try to argue that their cases are special and justify a departure from the normal rules on policy grounds, it will be more difficult now for the courts to apply the ‘back to the future’ principle. Generally speaking, the traditional causation rules should continue to protect professionals from unmeritorious claims.

Peter Causton is a business and professional risks assistant at Browne Jacobson