Chester (Respondent) v. Afshar (Appellant)
64. But the issue of causation in the form that has arisen in this case was present in Chappel v Hart (1998) 195 CLR 232, a decision of the High Court of Australia. In that case Gaudron, Gummow and Kirby JJ held, on facts which were similar to those of this case, that there was a causal connection between the failure to warn and the claimant's injury. The minority, McHugh and Hayne JJ, held that causation had not been established, as the defendant did not increase the risk to which the claimant was exposed when she underwent the operation.
65. The Court of Appeal in this case, having examined that decision, came to the conclusion that the majority in Chappel v Hart were right and that for the same reasons the decision of the trial judge in this case was right also. Sir Denis Henry, delivering the judgment of the court, explained the reasoning which had guided its decision in this way:  QB 356, 379, para 47:
66. In view of the importance which the Court of Appeal attached to the opinions of the majority in Chappel v Hart it is necessary to look more closely at the guidance which is offered by the views that were expressed in that case on both sides of the argument.
Chappel v Hart
67. Mrs Hart underwent surgery for the removal of a pharyngeal pouch in her oesophagus at the hands of Dr Chappel who was an ear, nose and throat specialist. During this surgery the oesophagus was perforated and an infection set in which damaged a laryngeal nerve. This resulted in damage to Mrs Hart's vocal chords and loss of vocal strength which affected her employment as a teacher librarian. She was assessed as medically unfit and had to retire from her employment. A claim that the operation had been performed negligently was not pursued. Mrs Hart's case was that she had not been warned of the risk, however slight, that perforation of the oesophagus might occur and of the laryngeal damage that might result from this. The trial judge found that no such warning had been given and that, if she had been warned of the risk of vocal damage, Mrs Hart would have postponed the operation and made further inquiries to minimise the risk.
68. The case is complicated by the fact that Mrs Hart maintained that if she had been warned of the risk she would have deferred the operation and had it performed instead by the most experienced surgeon in the field then available. That additional factor is not present in this case. There was no suggestion here that Miss Chester was more at risk at the hands of Mr Afshar due to any lack of experience on his part than she would have been at the hands of anyone else. It is necessary to bear in mind too that the law of Australia favours the objective rather than the subjective, or Bolam, approach to the duty to warn: Rogers v Whitaker (1992) 175 CLR 479, 490. Nevertheless there is obviously much common ground between the two cases.
69. In Chappel v Hart McHugh J, who was in the minority, took as his starting point the proposition that in principle, if the act or omission by the defendant has done no more than expose the plaintiff to a class of risk to which he or she would have been exposed irrespective of the defendant's act or omission, the law of torts should not require the defendant to pay damages: para 28. He developed this theme, drawing upon examples from the negligent acts in Monarch Steamship Co Ltd v Karlshamns Oljefabriker (A/B)  AC 196 and Carslogie Steamship Co Ltd v Royal Norwegian Government  AC 292, by considering how a causal connection might be established in the case of omissions such as the defendant's failure to warn the plaintiff that a particular route was liable to landslides. In para 32 he restated his proposition that a defendant is not causally liable, and therefore legally responsible, for wrongful acts or omissions if those acts or omissions would not have caused the plaintiff to alter his or her course of action, adding these sentences:
70. In para 34 McHugh J set out his conclusions as to whether a causal connection existed between a defendant's failure to warn of a risk of injury and the subsequent suffering of injury by the plaintiff as a result of the risk eventuating. Among these were the following:
71. In para 35 McHugh J said that in his opinion the defendant would escape liability only if the plaintiff did not prove that his failure to warn resulted in her consenting to a procedure that involved a higher risk of injury than would have been the case if the procedure had been carried out by another surgeon. He then reviewed the evidence. In para 41 he said that it was all one way, that perforation of the oesophagus was an inherent risk of the procedure which could occur even when reasonable skill and care were exercised. In para 42 he drew the conclusion that, on this approach, was inevitable. The plaintiff's claim must fail. The defendant's failure to warn did not increase the risk of injury involved in the procedure, and her claim that a causal connection existed between that failure and the injury had to be rejected.
72. Hayne J, the other justice who was in the minority, pointed out in para 116 that the "but for" test was neither a comprehensive nor exclusive test of causation. In his view the only connection between the failure to warn and the harm to the plaintiff was that but for the failure to warn she would not have been in harm's way: para 121. It was not enough to show that the subject matter of the failure to warn was the very subject matter of the damage: para 124. Important as this was, it was not determinative: para 125. Nor was the ambit of the liability to be decided only according to whether enlarging that ambit would promote careful conduct, as the question of causation had still to be answered: para 126. He rejected the plaintiff's case that she had lost the chance of better treatment, and he agreed with McHugh J that there was insufficient evidence to say that the defendant's failure to warn exposed the plaintiff to a greater risk of injury: para 146.
73. The approach of the minority is strong on logic and, so far as it goes, may be said to be impeccable in its reasoning. It is plain that the "but for" test is not in itself a sufficient test of causation. It is also plain that the requirements of causation would have been satisfied if Mrs Hart had been able to show that the failure to warn had exposed her to an increased risk of injury or that she would not have had the operation at all if she had been warned of the risk. But if the application of logic is to provide the answer, the consequences for a case where those elements are absent, as they are here, are stark. A duty was owed, the duty was breached and an injury was suffered that lay within the scope of the duty. Yet the patient to whom the duty was owed is left without a remedy.
74. Gaudron J, who was one of the three justices in the majority, observed that causation was to be approached as a question of fact to be answered by applying common sense to the facts of the particular case: para 6. She pointed out that questions of causation are not answered in a legal vacuum. Rather, they are answered in the legal framework in which they arise and for present purposes that framework was the law of negligence: para 7. It was not disputed that the defendant was under a duty to inform his patient of the risk. The duty was called into existence because of the foreseeability of that risk, it was not performed and the risk eventuated. That was often the beginning and the end of the inquiry whether breach of duty materially caused or contributed to the harm suffered: para 8. She accepted that where there is a duty to inform it is necessary for the plaintiff to give evidence as to what would or would not have happened if the information had been provided. But it was to apply sophistry rather than common sense to say that, although the risk of physical injury which came about called the duty of care into question, breach of that duty did not cause or contribute to that injury but simply resulted in the loss of an opportunity to pursue a different course of action: para 9. The physical injury having occurred, breach of the duty was treated as materially causing or contributing to that injury unless there was sufficient reason to the contrary: para 10.
75. Gummow J began his discussion by quoting the following passage from the Mason CJ's highly influential judgment in March v E & MH Stramare Pty Ltd (1991) 171 CLR 506, 509:
He referred also to Mason CJ's observation in that case at p 514 that, generally speaking, a sufficient causal connection is established if it appears that the plaintiff would not have sustained the injuries complained of had the defendant not been negligent. He then introduced his approach to the case with these words, in para 68:
In his opinion it was for Dr Chappel to demonstrate some good reason for denying to Mrs Hart recovery in respect of injury which she would not have suffered at his hands but for his failure to advise her, and he had failed to do so: para 69. To make good her case and obtain damages, Mrs Hart was not required to negative the proposition that any later treatment would have been attended with the same or a greater degree of risk: para 76.
76. Kirby J, the third justice in the majority, said in para 95 that for a time he was attracted by Dr Chappel's arguments, which had laid emphasis upon a logical examination of the consequences which would have flowed had he not breached his duty to warn his patient, but that ultimately he had concluded against them:
In para 96 he said that the standards which the court had set in Rogers v Whitaker (1992) 175 CLR 479, 490 as to the doctor's duty to warn the patient of a material risk inherent in the proposed treatment had fairly been described as onerous, but that they were the law and they had been established for good reason:
77. Academic comment on Chappel v Hart favours the view that was taken of the case by the majority. Peter Cane, "A Warning about Causation" (1999) 115 LQR 21, 23 said that the effect of adopting the central sense of "cause", which was that favoured by the minority, as appropriate to determining liability and compensation for breach of the duty to inform and warn would be very much to weaken the force and importance of that duty. At p 25 he said that, so far as Dr Chappel's role in the causal chain was concerned, it seemed to him that the majority view was correct. The desirable rule was that a doctor might be held liable for injury about the risk of which he had a duty to inform the patient, but not for injury the risk of which fell outside the duty to warn. Marc Stauch, "Taking the Consequences for Failure to Warn of Medical Risks" (2000) 63 MLR 261, 267, suggests that the High Court reached the correct conclusion in favour of liability, but not necessarily for the right reasons. The rationale which he favours is based on the special nature of the doctor's duty to advise his patient of risks of treatment. The principal reason for imposing this duty is to promote the patient's decision making autonomy. The law should deem the doctor to have assumed the risk of injury as though, in failing to mention it, he had warranted that it would not materialise. Or one could say that the doctor is estopped from pointing to the existence and unavoidable nature of the risk.
78. Professor Andrew Grubb, "Clinical Negligence: Informed Consent and Causation" (2002) 10 Med LRev 322, in his commentary on the decision of the Court of Appeal in this case (see also his Principles of Medical Law, 2nd ed (2004), p 200, para 3.161-3.162, where the same comments are repeated), referred, at p 324, to the fact that it had approved and applied the majority view in Chappel v Hart. After quoting part of the passage from para 47 of the Court of Appeal's judgment which I have set out above he said:
79. In "Medical non-disclosure, causation and risk: Chappel v Hart" (1999) 7 Torts LJ 1, Professor Tony Honoré said, at p 7, that at first sight the argument which commended itself to the minority in Chappel v Hart was cogent. Dr Chappel's advice related to a risk which Mrs Hart was bound, sooner or later, to run. On the assumption that the risk to her would have been the same whenever she had the operation (for reasons given earlier in this case note, he was proceeding on the assumption that the risk would have been exactly the same if she had been operated on by a surgeon more experienced in that type of operation than Dr Chappel), Dr Chappel neither exposed her to a risk that she need never run nor increased the risk she was bound to run in any case. So his failure to warn was not, on that assumption, a cause of the injury that she suffered.
80. But he was not content to leave the matter there. At p 8 he asked himself these questions:
His answer was that the latter proposition was the right one, for the following reason:
In his concluding remarks on the case he explained that, while he believed that the courts have power in certain cases to override causal considerations in order to vindicate a plaintiff's rights, this right must be exercised with great caution. He saw Chappel v Hart as an illustration of one of the types of case that he had in mind, where a plaintiff is entitled to recover from a defendant who has without negligence caused the sort of injury the risk of which the defendant should have warned the plaintiff. These, he said, were very unusual types of case in which causal principles have to be overridden so that a defendant bears the risk of harm that the defendant did not cause.
The answer to the problem of causation in this case
81. I would accept that a solution to this problem which is in Miss Chester's favour cannot be based on conventional causation principles. The "but for" test is easily satisfied, as the trial judge held that she would not have had the operation on 21 November 1994 if the warning had been given. But the risk of which she should have been warned was not created by the failure to warn. It was already there, as an inevitable risk of the operative procedure itself however skilfully and carefully it was carried out. The risk was not increased, nor were the chances of avoiding it lessened, by what Mr Afshar failed to say about it. As Professor Honoré in his note "Medical non-disclosure, causation and risk: Chappel v Hart" (1999) 7 Torts LJ 1, 4 has pointed out, to expose someone to a risk to which that person is exposed anyhow is not to cause anything.
82. Nor does it seem to me that an appeal to common sense alone will provide a satisfactory answer to the problem. In Stapley v Gypsum Mines Ltd  AC 663, 681 Lord Reid said that the question as to what caused an accident must be determined as a properly instructed and reasonable jury would decide it, by applying common sense to the facts of each particular case. The problem that had to be resolved in that case was whether the fault of the deceased's fellow workman, they both having disobeyed their foreman's instructions, was to be regarded as having contributed to the accident. Lord Reid's dictum was referred to by Mason CJ in March v E & MH Stramare Pty Ltd, 171 CLR 506, 515 in a passage which laid the basis for the approach to the issue of causation in Australia and was much referred to in Chappel v Hart.
83. An appeal to common sense when determining issues of causation is valuable in the right context. But out of its proper context, and without more, it may pull in two or more directions. This can be seen in Chappel v Hart where, following the guidance of Mason CJ in March, common sense was referred to and relied upon by justices on either side of the argument: Gaudron J at para 6; McHugh J, paras 23, 24; Kirby J, para 93; Hayne J, para 148. On its own common sense, and without more guidance, is no more reliable as a guide to the right answer in this case than an appeal to the views of the traveller on the London Underground. As I survey my fellow passengers on my twice weekly journeys to and from Heathrow Airport on the Piccadilly Line - such a variety in age, race, nationality and languages - I find it increasingly hard to persuade myself that any one view on anything other than the most basic issues can be said to be typical of all of them.
84. As Lord Hoffmann sought to emphasise in Environment Agency (formerly National Rivers Authority) v Empress Car Co (Abertillery) Ltd  2 AC 22, 29F, common sense answers to questions of causation will differ according to the purpose for which the question is asked. He supported this proposition by examples. He then said, at p 31H, that before answering questions about causation it was first necessary to identify the scope of the relevant rule and that this is a question of law, not of common sense fact. But even with this guidance, with which I agree, I find myself back at the same answer. The relevant rule is the duty which the law has imposed on the doctor - the duty to warn. Did the doctor's breach of that duty cause the patient's injury? It would appear that this question can only be answered in the negative. He did nothing which increased the risk to the patient, or even altered it. It was a risk to which she was exposed anyway. It was the same risk, irrespective of when or at whose hands she had the operation.
85. But the issue of causation cannot be separated from issues about policy. As Hart and Honoré point out in the Preface to Causation in the Law, 2nd ed (1985), pp xxxiv -xxxv, questions about causation which lie beyond the simple issue as to whether the harm could have occurred in the absence of the wrongful conduct tend to be issues of legal policy in disguise. They are better answered by asking whether, all things considered, the defendant should be held liable for the harm which ensued, or, on another view, whether the harm was foreseeable as within the risk, or was within the scope of the rule violated by the defendant. I would prefer to approach the issue which has arisen here as raising an issue of legal policy which a judge must decide. It is whether, in the unusual circumstances of this case, justice requires the normal approach to causation to be modified.
86. I start with the proposition that the law which imposed the duty to warn on the doctor has at its heart the right of the patient to make an informed choice as to whether, and if so when and by whom, to be operated on. Patients may have, and are entitled to have, different views about these matters. All sorts of factors may be at work here - the patient's hopes and fears and personal circumstances, the nature of the condition that has to be treated and, above all, the patient's own views about whether the risk is worth running for the benefits that may come if the operation is carried out. For some the choice may be easy - simply to agree to or to decline the operation. But for many the choice will be a difficult one, requiring time to think, to take advice and to weigh up the alternatives. The duty is owed as much to the patient who, if warned, would find the decision difficult as to the patient who would find it simple and could give a clear answer to the doctor one way or the other immediately.
87. To leave the patient who would find the decision difficult without a remedy, as the normal approach to causation would indicate, would render the duty useless in the cases where it may be needed most. This would discriminate against those who cannot honestly say that they would have declined the operation once and for all if they had been warned. I would find that result unacceptable. The function of the law is to enable rights to be vindicated and to provide remedies when duties have been breached. Unless this is done the duty is a hollow one, stripped of all practical force and devoid of all content. It will have lost its ability to protect the patient and thus to fulfil the only purpose which brought it into existence. On policy grounds therefore I would hold that the test of causation is satisfied in this case. The injury was intimately involved with the duty to warn. The duty was owed by the doctor who performed the surgery that Miss Chester consented to. It was the product of the very risk that she should have been warned about when she gave her consent. So I would hold that it can be regarded as having been caused, in the legal sense, by the breach of that duty.
88. The reasoning of Kirby J in Chappel v Hart, 195 CLR 232, para 95, which I would respectfully endorse, supports this approach. I am encouraged too by the answer which Professor Honoré gave to the question which he posed for himself in his case note on that case at p 8: "is this a case where courts are entitled to see to it that justice is done despite the absence of causal connection?" I would hold that justice requires that Miss Chester be afforded the remedy which she seeks, as the injury which she suffered at the hands of Mr Afshar was within the scope of the very risk which he should have warned her about when he was obtaining her consent to the operation which resulted in that injury.
89. For these reasons, and those which have been given by my noble and learned friends Lord Steyn and Lord Walker of Gestingthorpe, I would dismiss the appeal.
LORD WALKER OF GESTINGTHORPE
90. I have had the great advantage of reading in draft the opinions of my noble and learned friends Lord Steyn and Lord Hope of Craighead. I agree with them, and for the reasons which they give I would dismiss this appeal. But because of the general interest and difficulty of the issue of causation that arises in the appeal, and in view of the differences of opinion between your Lordships on that issue, I add some brief comments of my own.
91. In his opinion (para 51) Lord Hope rightly emphasises that the issue of causation cannot be properly addressed without a clear understanding of the scope of the defendant's duty: in this case, the surgeon's duty to warn his patient of the risk, small though it was, of nerve damage occurring during lumbar surgery. This is a point which your Lordships' House has noted in several recent decisions, including Banque Bruxelles Lambert SA v Eagle Star Insurance Co Ltd  AC 191, 212-213; Environment Agency (formerly National Rivers Authority) v Empress Car Co (Abertillery) Ltd  2 AC 22, 29-32; Kuwait Airways Corpn v Iraqi Airways Co (Nos 4 and 5)  2 AC 883, 1091, 1106.