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Session 2003 - 04
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Judgments - Chester (Respondent) v. Afshar (Appellant)


SESSION 2003-04
[2004] UKHL 41
on appeal from:[2002] EWCA Civ 724




Chester (Respondent)


Afshar (Appellant)



The Appellate Committee comprised:

Lord Bingham of Cornhill

Lord Steyn

Lord Hoffmann

Lord Hope of Craighead

Lord Walker of Gestingthorpe




Chester (Respondent) v. Afshar (Appellant)

[2004] UKHL 41


My Lords,

    1.  The central question in this appeal is whether the conventional approach to causation in negligence actions should be varied where the claim is based on a doctor's negligent failure to warn a patient of a small but unavoidable risk of surgery when, following surgery performed with due care and skill, such risk eventuates but it is not shown that, if duly warned, the patient would not have undergone surgery with the same small but unavoidable risk of mishap. Is it relevant to the outcome of the claim to decide whether, duly warned, the patient probably would or probably would not have consented to undergo the surgery in question?

    2.  I am indebted to my noble and learned friend Lord Hope of Craighead for his detailed account of the facts and the history of these proceedings, which I need not repeat.

    3.  For some six years beginning in 1988 the claimant, Miss Chester, suffered repeated episodes of low back pain. She was conservatively treated by Dr Wright, a consultant rheumatologist, who administered epidural and sclerosant injections. An MRI scan in 1992 showed evidence of disc protrusions. In 1994, on the eve of a professional trip abroad, Miss Chester suffered another episode of pain and disability: she could "hardly walk", and had reduced control of her bladder. Dr Wright gave another epidural injection, and Miss Chester was able to make the trip, using a wheelchair at Heathrow. But after the trip the pain returned. A further MRI scan revealed marked protrusion of discs into the spinal canal. After further conservative treatment which proved ineffective, Dr Wright referred Miss Chester to Mr Afshar, a distinguished consultant neurosurgeon with much experience of disc surgery, although Miss Chester was understandably reluctant to undergo surgery if this could be avoided.

    4.  On accepting Miss Chester as a patient, Mr Afshar became subject to a legal as well as a professional duty to exercise reasonable care and skill in examining her; in assessing her case; and in advising on the need for surgery to alleviate her condition. If surgery was advised and accepted, he was bound to exercise reasonable care and skill in operating and in supervising her post-operatively. Mr Afshar did examine Miss Chester, did advise and did undertake surgery. All these duties Mr Afshar duly performed. Miss Chester contended at trial that Mr Afshar had performed the operation negligently, but the judge rejected this complaint and in the event the Court of Appeal was not asked to rule on that question.

    5.  Mr Afshar was however subject to a further, important, duty: to warn Miss Chester of a small (1%-2%) but unavoidable risk that the proposed operation, however expertly performed, might lead to a seriously adverse result, known in medical parlance as cauda equina syndrome. The existence of such a duty is not in doubt. Nor is its rationale: to enable adult patients of sound mind to make for themselves decisions intimately affecting their own lives and bodies. There was a conflict of evidence at trial on what was said by Mr Afshar about the risk of an adverse outcome, but the judge resolved this conflict against him, holding that he had not given the warning which he should have given, and the Court of Appeal did not give him leave to challenge that conclusion. So it must be accepted that Mr Afshar did not give Miss Chester the warning which he should have given of the small but unavoidable risk that surgery might not improve Miss Chester's condition but might affect it adversely. As it was, the surgery, although skilfully performed, led to her suffering the cauda equina syndrome.

    6.  Had the evidence entitled the judge to conclude, and had he concluded, that Miss Chester, if warned as she should have been, would probably not have agreed to surgery, she would on conventional principles have been entitled to recover damages. The measure of damages would have reflected the difference between Miss Chester's condition following surgery and the condition she would probably have been in without surgery, but there would have been no problem of causation. Had the warning been given, Miss Chester would (on such a finding) have acted differently, and her additional injury would be directly attributable to the absence of warning. The same would be true if the evidence had entitled the judge to conclude, and if he had concluded, that Miss Chester, if properly warned as she should have been, could and would have minimised the risk of surgery by entrusting herself to a different surgeon, or undergoing a different form of surgery, or (in another kind of case) losing weight or giving up smoking.

    7.  But the judge made none of these findings. He concluded that, if duly warned, Miss Chester would not have undergone surgery three days after her first consultation with Mr Afshar, but would, very understandably, have wished to discuss the matter with others and explore other options. But he did not find (and was not invited to find) that she would probably not have undergone the surgery or that there was any way of minimising the small degree of risk inherent in surgery. As my noble and learned friend Lord Hope observes in paragraph 61 of his opinion, the risk

    "was also liable to occur at random, irrespective of the degree of care and skill with which the operation was conducted by the surgeon. This means that the risk would have been the same whenever and at whoever's hands she had the operation … it is difficult to say that his failure was the effective cause of the injury."

    8.  It is now, I think, generally accepted that the "but for" test does not provide a comprehensive or exclusive test of causation in the law of tort. Sometimes, if rarely, it yields too restrictive an answer, as in Fairchild v Glenhaven Funeral Services Ltd [2002] UKHL 22, [2003] 1 AC 32. More often, applied simply and mechanically, it gives too expansive an answer: "But for your negligent misdelivery of my luggage, I should not have had to defer my passage to New York and embark on SS Titanic". But, in the ordinary run of cases, satisfying the "but for" test is a necessary if not a sufficient condition of establishing causation. Here, in my opinion, it is not satisfied. Miss Chester has not established that but for the failure to warn she would not have undergone surgery. She has shown that but for the failure to warn she would not have consented to surgery on Monday 21 November 1994. But the timing of the operation is irrelevant to the injury she suffered, for which she claims to be compensated. That injury would have been as liable to occur whenever the surgery was performed and whoever performed it.

    9.  Thus the question arises whether Miss Chester should be entitled to recover even though she cannot show that the negligence proved against Mr Afshar was, in any ordinary sense, a cause of her loss. I am of course impressed by the weight and distinction of the academic opinion supporting the decisions of the judge and the Court of Appeal in this case. But if failure to warn and the occurrence of injury which should have been the subject of the warning are, without more, enough to found a successful claim, the claimant would presumably succeed even in a case like Smith v Barking, Havering and Brentwood Health Authority [1994] 5 Med LR 285, where it is found on the balance of probabilities that the claimant would have consented to the operation even if properly advised. That seems to me, with respect to those who hold otherwise, to be a substantial and unjustified departure from sound and established principle. It is trite law that damage is the gist of the action in the tort of negligence. It is not suggested that it makes any difference whether a claim such as the present is framed in tort or in contract. A claimant is entitled to be compensated for the damage which the negligence of another has caused to him or her. A defendant is bound to compensate the claimant for the damage which his or her negligence has caused the claimant. But the corollaries are also true: a claimant is not entitled to be compensated, and a defendant is not bound to compensate the claimant, for damage not caused by the negligence complained of. The patient's right to be appropriately warned is an important right, which few doctors in the current legal and social climate would consciously or deliberately violate. I do not for my part think that the law should seek to reinforce that right by providing for the payment of potentially very large damages by a defendant whose violation of that right is not shown to have worsened the physical condition of the claimant. I would respectfully adopt the reasoning of McHugh J in his dissenting judgment in Chappel v Hart (1998) 195 CLR 232.

    10.  For these reasons, and also those given by my noble and learned friend Lord Hoffmann, I would allow this appeal.


My Lords,

    11.  The facts of this case can be simplified. The claimant suffered from low back pain. A neurosurgeon advised her to undergo an elective lumbar surgical procedure. The procedure entails a 1%-2% chance of serious neurological damage arising from the operation. The claimant was entitled to be informed of this fact. In breach of the common law duty of care the surgeon failed to inform the claimant of the risk. The claimant reluctantly agreed to the operation. Three days after her consultation with the surgeon the claimant underwent the surgery. The claimant sustained serious neurological damage. In the result the very injury about which she should have been warned occurred. The surgeon had not been negligent in performing the operation: he did not increase the risks inherent in the surgery. On the other hand, if the claimant had been warned she would not have agreed to the operation. Instead she would have sought further advice on alternatives. The judge found that if the claimant had been properly warned the operation would not have taken place when it did, if at all. The judge was unable to find whether if the claimant had been duly warned she would with the benefit of further medical advice have given or refused consent to surgery. What is clear is that if she had agreed to surgery at a subsequent date, the risk attendant upon it would have been the same, ie 1%-2%. It is therefore improbable that she would have sustained neurological damage.

    12.  On these facts the judge found that the claimant had established a causal link between the breach and the injury she had sustained and held that the defendant was liable in damages. In a detailed and careful judgment the Court of Appeal (Hale LJ, Sir Christopher Slade and Sir Denis Henry) upheld the conclusion of the judge: Chester v Afshar [2002] EWCA Civ 724; [2003] QB 356.

    13.  Counsel for the surgeon submitted that it is contrary to general principles of tort law to award damages when a defendant's wrong has not been proved to have increased the claimant's exposure to risk. He argued that in order to establish causation in a case of a surgeon's failure to warn a patient of a significant risk of injury, the patient must prove both 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. The only qualification was the case where a claimant could prove an accelerated onset of injury. That the claimant could not do on the facts of the case. On analysis it was an all or nothing case. Counsel said that the injury that the claimant sustained was just a coincidence, a piece of abominable bad luck, like lightning striking a person. This was a powerful argument and persuasively presented.

    14.  The legal context requires consideration of a number of other relevant factors. First, the nature of the correlative rights and duties of the patient and surgeon must be kept in mind. The starting point is that every individual of adult years and sound mind has a right to decide what may or may not be done with his or her body. Individuals have a right to make important medical decisions affecting their lives for themselves: they have the right to make decisions which doctors regard as ill advised. Surgery performed without the informed consent of the patient is unlawful. The court is the final arbiter of what constitutes informed consent. Usually, informed consent will presuppose a general warning by the surgeon of a significant risk of the surgery.

    15.  In the case before the House a single cause of action is under consideration, viz the tort of negligence. How a surgeon's duty to warn a patient of a serious risk of injury fits into the tort of negligence was explained by Lord Woolf MR, with the agreement of Roch and Mummery LJJ, in Pearce v United Bristol Healthcare NHS Trust [1999] PIQR P53. After reviewing a trilogy of decisions in Bolam v Friern Hospital Management Committee [1957] 1 WLR 582; Sidaway v Board of Governors of the Bethlem Royal Hospital and the Maudsley Hospital [1985] AC 871 and Bolitho v City and Hackney Health Authority [1998] AC 232, Lord Woolf observed, at P59:

    "In a case where it is being alleged that a plaintiff has been deprived of the opportunity to make a proper decision as to what course he or she should take in relation to treatment, it seems to me to be the law, as indicated in the cases to which I have just referred, that if there is a significant risk which would affect the judgment of a reasonable patient, then in the normal course it is the responsibility of a doctor to inform the patient of that significant risk, if the information is needed so that the patient can determine for him or herself as to what course he or she should adopt."

    16.  A surgeon owes a legal duty to a patient to warn him or her in general terms of possible serious risks involved in the procedure. The only qualification is that there may be wholly exceptional cases where objectively in the best interests of the patient the surgeon may be excused from giving a warning. This is, however, irrelevant in the present case. In modern law medical paternalism no longer rules and a patient has a prima facie right to be informed by a surgeon of a small, but well established, risk of serious injury as a result of surgery.

    17.  Secondly, not all rights are equally important. But a patient's right to an appropriate warning from a surgeon when faced with surgery ought normatively to be regarded as an important right which must be given effective protection whenever possible.

    18.  Thirdly, in the context of attributing legal responsibility, it is necessary to identify precisely the protected legal interests at stake. A rule requiring a doctor to abstain from performing an operation without the informed consent of a patient serves two purposes. It tends to avoid the occurrence of the particular physical injury the risk of which a patient is not prepared to accept. It also ensures that due respect is given to the autonomy and dignity of each patient. Professor Ronald Dworkin (Life's Dominion: An Argument about Abortion and Euthanasia, 1993) explained these concepts at p 224:

    "The most plausible [account] emphasizes the integrity rather than the welfare of the choosing agent; the value of autonomy, on this view, derives from the capacity it protects: the capacity to express one's own character - values, commitments, convictions, and critical as well as experiential interests - in the life one leads. Recognizing an individual right of autonomy makes self-creation possible. It allows each of us to be responsible for shaping our lives according to our own coherent or incoherent - but, in any case, distinctive - personality. It allows us to lead our lives rather than be led along them, so that each of us can be, to the extent a scheme of rights can make this possible, what we have made of ourselves. We allow someone to choose death over radical amputation or a blood transfusion, if that is his informed wish, because we acknowledge his right to a life structured by his own values."

    19.  Fourthly, it is a distinctive feature of the present case that but for the surgeon's negligent failure to warn the claimant of the small risk of serious injury the actual injury would not have occurred when it did and the chance of it occurring on a subsequent occasion was very small. It could therefore be said that the breach of the surgeon resulted in the very injury about which the claimant was entitled to be warned.

    20.  These factors must be considered in combination. But they must also be weighed against the undesirability of departing from established principles of causation, except for good reasons. The collision of competing ideas poses a difficult question of law.

    21.  That such problems do not necessarily have a single right answer is illustrated by the judgment of the Australian High Court in Chappel v Hart (1998) 195 CLR 232. A surgeon failed to warn a patient of a small risk of an operation. She underwent the operation. In the result the very injury of which she should have been warned took place. As in the present case the position was that the patient would not have had the operation at the time and place when she did. If the patient had the operation on a subsequent occasion, the outcome would probably have been uneventful. On these facts the court decided by a majority of three (Gaudron, Gummow and Kirby JJ) to two (McHugh and Hayne JJ) that the patient was entitled to recover substantial damages from the surgeon for the physical injuries suffered as a result of the operation performed on her. The judgments are illuminating. For my part I found the dissenting judgment of McHugh J particularly powerful, and rightly counsel for the surgeon relied heavily on it. Chappel v Hart mirrors the issues and arguments in the present case. It will not serve any useful purpose to cite at length from the judgments. I also do not think a process of counting heads in a case such as Chappel v Hart is a particularly helpful exercise in regard to the issue before the House. At the very least, however, this Australian case reveals two fundamentally different approaches, the one favouring firm adherence to traditionalist causation techniques and the other a greater emphasis on policy and corrective justice.

    22.  The House was referred to a valuable body of academic literature which discusses problems such as arose in Chappel v Hart, and in the present case, in some detail. Not surprisingly, the authors approach the matter from slightly different angles. It is, however, fair to say that there is general support for the majority decision in Chappel v Hart, and for the view which prevailed in the Court of Appeal in the present case: see Cane, "A Warning about Causation" (1999) 115 LQR 21; Grubb, "Clinical Negligence: Informed Consent and Causation" (2002) 10 Med LRev 322; Honoré, "Medical non-disclosure: causation and risk: Chappel v Hart" (1999) 7 Torts LJ 1; Jones, 'But for' causation in actions for non-disclosure of risk", (2002) 18 PN 192; Stapleton, "Cause-in-Fact and Scope of Liability for Consequences" (2003) 119 LQR 388; Stauch, "Taking the Consequences for Failure to Warn of Medical Risks" (2000) 63 MLR 261. The case note by the co-author of the seminal treatise on causation is particularly interesting. Professor Honoré said, at p 8:

    "Does it follow that Mrs Hart should not recover ? Or is this a case where courts are entitled to see to it that justice is done despite the absence of causal connection? I think it is the latter and for the following reason. The duty of a surgeon to warn of the dangers inherent in an operation is intended to help minimise the risk to the patient. But it is also intended to enable the patient to make an informed choice whether to undergo the treatment recommended and, if so, at whose hands and when. Dr Chappel violated Mrs Hart's right to choose for herself, even if he did not increase the risk to her. Judges should vindicate rights that have been violated if they can do so consistently with the authority of statutes and decided cases. In this case the High Court did just this, in effect by making Dr Chappel, when he operated on Mrs Hart, strictly liable for any injury he might cause of the type against which he should have warned her. For Dr Chappel did cause the harm that Mrs Hart suffered, though not by the advice he failed to give her. He did so by operating on her and, though he operated with due care, he slit open her oesophagus with disastrous consequences. Morally he was responsible for the outcome of what he did. … All the High Court has therefore done is to give legal sanction to an underlying moral responsibility for causing injury of the very sort against the risk of which the defendant should have warned her.

    Do the courts have power in certain cases to override causal considerations in order to vindicate a plaintiff's rights? I believe they do though the right must be exercised with great caution."

In my view Professor Honoré was right to face up to the fact that Chappel v Hart - and therefore the present case - cannot neatly be accommodated within conventional causation principles. But he was also right to say that policy and corrective justice pull powerfully in favour of vindicating the patient's right to know.

    23.  It is true that there is no direct English authority permitting a modification of the approach to the proof of causation in a case such as the present. On the other hand, there is the analogy of Fairchild v Glenhaven Funeral Services Ltd [2003] 1 AC 32 which reveals a principled approach to such a problem. The facts were that claimants had developed mesothelioma after exposure to asbestos dust while employed by different and entirely separate employers. Breach of duty was established against all the employers. But on a balance of probabilities the employees could not prove the onset of the disease due to any particular or cumulative exposure. Given that each employer's wrongdoing had materially increased the risk of contracting the disease, the House of Lords held that a modified approach to proof of causation was justified. Lord Bingham of Cornhill ended his opinion by observing (para 35, p 68) "I prefer to recognise that the ordinary approach to proof of causation is varied than to resort to the drawing of legal inferences inconsistent with the proven facts." Similarly, Lord Nicholls of Birkenhead expressly proceeded on the basis that the ordinary "but for" standard of causation was not satisfied. He said (para 45, p 71) that "Instead the court is applying a different and less stringent test". Relying on "the justice and the policy of common law and statute", Lord Hoffmann arrived at the same conclusion: para 63, p 75. Relying on policy reasons Lord Rodger of Earlsferry concluded that on policy grounds a lower threshold test was justified: para 168, p 118. The Fairchild case is, of course, very different from the facts of the present case. A modification of causation principles as was made in Fairchild will always be exceptional. But it cannot be restricted to the particular facts of Fairchild. Lord Bingham of Cornhill observed in Fairchild that "It would be unrealistic to suppose that the principle here affirmed will not over time be the subject of incremental and analogical development": para 34, p 68. At the very least Fairchild shows that where justice and policy demand it a modification of causation principles is not beyond the wit of a modern court.

    24.  Standing back from the detailed arguments, I have come to the conclusion that, as a result of the surgeon's failure to warn the patient, she cannot be said to have given informed consent to the surgery in the full legal sense. Her right of autonomy and dignity can and ought to be vindicated by a narrow and modest departure from traditional causation principles.

    25.  On a broader basis I am glad to have arrived at the conclusion that the claimant is entitled in law to succeed. This result is in accord with one of the most basic aspirations of the law, namely to right wrongs. Moreover, the decision announced by the House today reflects the reasonable expectations of the public in contemporary society.

    26.  The result ought to come as no surprise to the medical profession which has to its credit subscribed to the fundamental importance of a surgeon's duty to warn a patient in general terms of significant risks: Royal College of Surgeons: "Good Surgical Practice" (2002) chap 4, guidelines on consent.

    27.  For these reasons as well as the reasons given by my noble and learned friends Lord Hope of Craighead and Lord Walker of Gestingthorpe I would dismiss the appeal.


My Lords,

    28.  The purpose of a duty to warn someone against the risk involved in what he proposes to do, or allow to be done to him, is to give him the opportunity to avoid or reduce that risk. If he would have been unable or unwilling to take that opportunity and the risk eventuates, the failure to warn has not caused the damage. It would have happened anyway.

    29.  The burden is on a claimant to prove that the defendant's breach of duty caused him damage. Where the breach of duty is a failure to warn of a risk, he must prove that he would have taken the opportunity to avoid or reduce that risk. In the context of the present case, that means proving that she would not have had the operation.

    30.  The judge made no finding that she would not have had the operation. He was not invited by the claimant to make such a finding. 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 evidence was that the risk could have been precisely the same if she had it at another time or by another surgeon. A similar argument has been advanced before this House.