The judgment of the Court of Appeal in Duce v Worcestershire Acute Hospitals NHS Trust [2018] EWCA Civ 1307 deals with a number of matters.  Here I want to look at the question of proving causation in a case where the claimant was alleging that she had not given informed consent.  The Court specifically rejected an argument that a claimant did not have to prove causation in cases where informed consent was not given. The burden remained on the claimant to show that a different course of action would have been taken if they had been given appropriate warnings.


“I accordingly agree with the respondent that the majority decision in Chester does not negate the requirement for a claimant to demonstrate a “but for” causative effect of the breach of duty, as that requirement was interpreted by the majority, and specifically that the operation would have not have taken place when it did.”


The claimant underwent an operation and suffered severe nerve damage. There was no suggestion that the operation was performed negligently. Her case was that she was not adequately warned of the risks of the operation and if she had been warned she would have not have consented.  The claimant failed at trial.  The Court of Appeal dismissed her appeal, it upheld the finding that there had been no breach of duty.  It then considered the arguments relating to causation.


The claimant argued that it as not necessary to prove that she would have taken different steps if she had received adequate warning.

“Ground 2: The Test for Causation
    1. The appellant’s case on causation at trial was that had a warning been given she would not have had surgery on that day. That was the pleaded case and the case put in argument at trial.
    2. The judge rejected that case on the evidence and found at [59] that even if there had been a warning to the effect said to be required the appellant “would have proceeded with the operation on that day”.
    3. The appellant now submits that as a matter of law there was no need to prove this. Reliance is placed on Lord Hope’s judgment in Chester at [86]-[87]:
“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.”
    1. It is submitted that this creates an alternative pathway to causation in consent cases, subject to three requirements:
(1) The injury was intimately involved with the duty to warn.
(2) The duty was owed by the doctor who performed the surgery to which the patient had consented.
(3) The injury was the product of the very risk that the patient should have been warned about when they gave their consent.
    1. The appellant contends that all three of those requirements are satisfied in this case.
    2. Mr Donovan QC submits that this broad reading of the causation test established in Chester is bolstered by the policy arguments identified by the Supreme Court in Montgomery. Reliance is placed, in particular, on references made to the change in doctor-patient relationships, such that patients are now widely regarded as holding rights and treated as consumers exercising choices [75]; changes in general society such that patients should no longer be viewed as generally uninformed [76]; the shift in medical practice towards informed consent [77]; the recognition of informed consent as a human right [80] and to the statements that “the need for informed consent [is] firmly part of English law” [107].
    3. As Mr Havers QC points out, this argument, if correct, amounts to a wholesale disapplication of conventional causation principles in consent cases.
    4. The passages from Lord Hope’s judgment which are relied upon need to be considered in their factual context.
    5. In his majority judgment Lord Steyn summarised the facts at [11]. His summary included the following:

“…..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, i.e. 1%–2%. It is therefore improbable that she would have sustained neurological damage.” (underlining added)

    1. The significance of the underlined passages is explained at [19] of Lord Steyn’s judgment where he says:

“… 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.” (underlining added)

    1. This is a finding of “but for” causation, or causation in fact. The injury was a result of the breach of duty because (i) the operation would not have taken place when it did and (ii) the risk of injury was very small and so was unlikely to have occurred if the operation had been carried out on a subsequent occasion.
    2. Lord Hope at the outset of his judgment at [39] emphasises that the issue of law “rests upon two findings of fact”. The first was the finding of failure to warn and the second was that “if she had known of the actual risks of the proposed surgery, Miss Chester would not have consented to the operation taking place on 21 November 1994 and that before deciding what to do she would have sought a second, or possibly, a third opinion.”
    3. At [40] Lord Hope then identified the “question of law which arises from these findings” as being “whether it was sufficient for Miss Chester to prove that, if properly warned, she would not have consented to the operation which was in fact performed and which resulted in the injury, or whether it was necessary for her to prove also that she would never have had that operation” (underlining added).
    4. At [61] Lord Hope explained that proof that, if properly warned, she would not have consented to the operation establishes “but for” causation:
“It can be said that Miss Chester would not have suffered her injury “but for” Mr Afshar’s failure to warn her of the risks, as she would have declined to be operated on by him on 21 November 1994.”
The same point is made at [81].
    1. He also notes at [61] that it is difficult to say that Mr Afshar’s failure to warn was “the effective cause of the injury” given that it had not been proved that she would never have had the operation or that the failure to warn had exposed her to an increased risk of injury – see also [73].
    2. At [62] he stresses the fact that the risk of injury from any subsequent injury would have been very small:
“If she had been given the warning she would have avoided that risk, and the chances of her being injured in that way if she had had the operation later would have been very small—between 1% and 2% on Mr Findlay’s evidence.”
    1. Lord Hope then discusses the issue of causation more generally, noting at [73] that:
“It is plain that the “but for” test is not in itself a sufficient test of causation”
    1. In the section of his judgment headed “The answer to the problem of causation in this case” Lord Hope stresses the relevance of the particular facts of the case and considers whether “in the unusual circumstances of this case justice requires the normal approach to be modified”. He then concludes that justice does so require for the reasons set out at [86]-[87] and, in particular, the fact that the injury “was the product of the very risk that she should have been warned about when she gave her consent” [87].
    2. When paragraphs [86]-[87] of Lord Hope’s judgment are considered in context in my judgment it is clear that he is not setting out a free-standing test, as the appellant contends, but rather the circumstances which justify the normal approach to causation being modified. That modification was to treat a “but for” cause that was not an effective cause as a sufficient cause in law in the “unusual” circumstances of the case.
    3. This is also how the third member of the majority, Lord Walker, approached the matter. At [94] he observes that in this case:
“Bare “but for” causation is powerfully reinforced by the fact that the misfortune which befell the claimant was the very misfortune which was the focus of the surgeon’s duty to warn.”
  1. It was the powerful reinforcement provided by the close link between the injury suffered and the duty to warn that led Lord Walker also to conclude that “but for” causation was sufficient.
  2. I accordingly agree with the respondent that the majority decision in Chester does not negate the requirement for a claimant to demonstrate a “but for” causative effect of the breach of duty, as that requirement was interpreted by the majority, and specifically that the operation would have not have taken place when it did.
  3. It is also to be noted that in the recent case of Correia v University Hospital of North Staffordshire NHS Trust [2017] EWCA Civ 356 the court emphasised at [28] that if “the exceptional principle of causation” established by Chester is to be relied upon it is necessary to plead and prove that, if warned of the risk, the claimant would have deferred the operation.
  4. For all these reasons, I reject Ground 2. For completeness it should be noted that Mr Havers QC reserved the right to argue that Chester was wrongly decided if this case was to go to the Supreme Court.”


The claimant also attempted to overturn the trial judge’s finding that she would have proceeded with the operation in any event. The Court of Appeal rejected that argument.

  1. This is a challenge to the finding of fact made by the judge that even if the appellant had been warned as it was contended she should have been, she would still have proceeded with the operation as she did.
  2. This finding is set out in [59] of the judgment. Mr Donovan QC treats the factors identified in that paragraph as being the sole factors considered by the judge and contends that this shows that the judge failed to take into account a highly material consideration, namely that, since the predominant reason for seeking the operation was pain relief, a warning of the risk of further and different chronic pain would have caused her to reconsider.
  3. The finding made by the judge in [59] was made against the background of all the evidence at trial. This includes relevant evidence referred to at various earlier parts of the judgment, such as [6](i)(v)(vii) and [9]-[13]. It also includes the compelling evidential points made at [56]-[58].
  4. As the respondent submits, there was abundant evidence to support the judge’s finding. The appellant had on several occasions been urged by medical practitioners (both GPs and gynaecological surgeons) to consider the less invasive alternatives to TAH, which she was aware was major surgery which carried significant risks; she nonetheless declined to pursue those less invasive options and elected instead to undergo TAH.
  5. Further, paragraph [59] itself stresses the important point that the appellant was willing to go ahead despite the fact that there were “a number of other quite serious risks”. As the judge found, “she wanted it all taken away” despite known serious risks.
  6. There is in any event no substance in the suggestion that the judge omitted from consideration the appellant’s motivation(s) for proceeding to surgery. The judge considered in detail the applicant’s long history of symptoms from which she hoped to gain relief by undergoing surgery. That history was justifiably rightly considered to weigh in favour of her choosing to undergo surgery when she did, even if a different warning as to the risk of pain had been given.
  7. For all these reasons, I reject Ground 3.”