This article originally appeared in Issue 5 (May 2020).
Somewhat surprisingly, the Court of Appeal has upheld the controversial judgment of Stewart J (covered in Issue 3) that the Claimant’s wife would not have died if she had been referred to hospital, despite having made a specific finding that the Claimant had not proved the precise train of events by which her death would have been prevented.
The Defendant GP admitted that he had negligently failed to refer the Deceased to hospital when she attended his surgery with chest pain and breathlessness. It was common ground that, had the Deceased been referred to hospital at the proper time, she would have been diagnosed as having a pulmonary embolism. However, causation was denied.
As noted in our consideration of the High Court judgment in Issue 3, a large amount of detailed evidence was led as to what would have happened to the deceased had she been admitted to hospital, and whether such treatments would have led to her survival. The key parts of Stewart J’s judgment were his comments that “the Claimant has the burden of proving causation. Yet the Claimant needs to prove no more than that Mrs Marshall would probably have survived had she been admitted to hospital. The Claimant does not need to prove the precise mechanism by which her survival would have been achieved.” Stewart J then went on to hold that there “cannot be an inference, much less a finding, merely on the basis that a number of possibilities amount to a probability that death would have been avoided.” However, he ultimately went on to find in the Claimant’s favour on causation, making the following comments at  to :
“Thus the expert medical evidence to which I have referred and the statistical evidence demonstrate that at the time when Mrs Marshall should have presented at hospital, anybody rating her chances of survival would have put them at being very high. Tragically, she did in fact die out of hospital. In the situation which occurred, detailed analysis of such evidence as we have cannot lead the court to find that by such and such a mechanism, or at any particular stage, the course of events would probably have been different. This is overwhelmingly because of a large number of unknowns. The court, in looking at the evidence as a whole, must take a common sense and pragmatic approach to that evidence, in circumstances where it is equivocal. The court must also be wary of relying on the statistical evidence in the literature which has a number of variables. Had the statistical evidence, in conjunction with the expert evidence, have led to the conclusion that Mrs Marshall’s chances of dying would have been assessed on presentation as only slightly better than 50-50, I would have found for the Defendant. However, the above evidence of Professor Empey and Doctor Gomez, in conjunction with the medical literature, drives me to the conclusion that on the clear balance of probabilities she would have survived.”
The Court of Appeal
The Claimant argued in the Court of Appeal that where a claimant establishes a breach of duty of care and shows that the injury that follows is of a kind likely to have resulted from a breach of that kind, that is usually enough to enable the court to find that the injury has resulted from the breach. Here the Defendant admitted a breach of duty in failing to refer the Deceased to hospital on 25 April 2014 in respect of what he should have seen as the signs of the pulmonary embolism, which in fact she had. The likely result of that breach was that she would die from the embolism, in the absence of specialist treatment. She did die and it was submitted that was enough to sustain the finding that the death was caused by the breach. It was not necessary for the Claimant to show on the balance of probability, the precise mechanism, or route of treatment, that would have led to the Deceased’s survival.
The Defendant argued that where a judge found that the Claimant had failed to establish to the necessary standard that the Deceased would have survived by the receipt of either or both of the only possible treatments for her condition, then the claim must fail. The judge should not have posed a separate overriding question based on general survival rates of patients with pulmonary embolisms in hospital and/or a general analysis that most people do not die from pulmonary embolisms in hospital.
McCombe LJ at  cited with approval Clerk and Lindsell to the effect that:
“If the evidence is that, say, 80 per cent of patients survive with prompt treatment, but 20 per cent die even with prompt treatment, the fact that the patient died following delayed treatment does not establish that he probably fell into the 20 per cent category at the outset and therefore the delay did not contribute to the death. The assessment of causation would turn upon the detailed medical evidence, both as to the overall statistical chances of survival and the particular condition and circumstances of the patient…. Proof of causation is almost inevitably about a burden of persuasion and sometimes statistics can be highly persuasive.”
McCombe LJ at  held that Stewart J had not fallen into error by asking the question “Looking at the evidence as a whole, is it nevertheless more likely than not that the Claimant would have survived had she been referred to Southend Hospital?” McCombe LJ held that Stewart J was right to take the “common sense and pragmatic view” of “the evidence as a whole“. He concluded at  that:
“…without being able to prove the precise mechanism of survival to the requisite standard, after exhaustive consideration of all the material, the Respondent did satisfy the judge “clearly” that the result that occurred was caused by the breach of duty. In my judgment, he was entitled to be so satisfied. This was not a case in which statistics were used to transpose a strong case in the Appellant’s favour into a decision in favour of the Respondent. I also reject the argument for the Appellant that to uphold the judge’s judgment would be to say that statistics are determinative of causation issues such as the present. The judge’s decision was heavily focused upon the Deceased’s condition and likely presentation at hospital. As the Appellant’s own case on the pleadings and the authorities showed, there is a legitimate place for statistical evidence in cases of this type. The employment of that evidence by the judge in this case was closely linked by him to his assessment of the evidence as to the Deceased’s own particular condition, in which her prospects of survival (on hypothetical admission to hospital) were very good indeed. I remind myself that, on the judge’s assessment (at paragraph 146) this was not simply a 50/50 case on the statistics. That will not be so in every case. Each case (like this one) will be intensely “fact-specific”.”
Any decision involving causation, clinical negligence, and statistics is likely to be highly fact sensitive. However, this case will potentially be of some assistance to claimants faced with complex counter factual scenarios where there are a number of different causal hoops to jump through on the way to establishing a clear causal chain. Not least because of the Court of Appeal’s specific endorsement of the authority of Drake v Harbour  EWCA Civ 25, where Toulson LJ held at :
“In the absence of any positive evidence of breach of duty, merely to show that a claimant’s loss was consistent with breach of duty by the defendant would not prove breach of duty if it would also be consistent with a credible non-negligent explanation. But where a claimant proves both that a defendant was negligent and that loss ensued which was of a kind likely to have resulted from such negligence, this will ordinarily be enough to enable a court to infer that it was probably so caused, even if the claimant is unable to prove positively the precise mechanism. That is not a principle of law nor does it involve an alteration in the burden of proof; rather, it is a matter of applying common sense. The court must consider any alternative theories of causation advanced by the defendant before reaching its conclusion about where the probability lies. If it concludes that the only alternative suggestions put forward by the defendant are on balance improbable, that is likely to fortify the court’s conclusion that it is legitimate to infer that the loss was caused by the proven negligence.