Introduction
This was an appeal by Dr Mario Shembri against a finding of Mr Justice Stewart [1]. Mrs Marshall had died on 26/04/2014 as a result of an untreated pulmonary embolism. It had been admitted that Dr Shembri was in breach of his duty of care in failing to refer Mrs Marshall to hospital but it was denied that this failure was causative of death. At trial the claimant had argued that had Mrs Marshall been promptly referred to hospital she would not have died. At the appeal it was argued on behalf of Dr Shembri that the claimant had failed to prove that Mrs Marshall would have survived had she been admitted to hospital and on that basis the claim must fail.
The Facts
Mrs Marshall had attended her GP Dr Shembri at about 16.00 hours on 25/04/2014. She was complaining of chest pain and breathlessness. She had previously suffered a pulmonary embolism [2] or PE in 2008 and she has been successfully treated for that at hospital.
Dr Shembri had examined Mrs Marshall and told her that the most probable cause of her symptoms was muscular strain affecting her hiatus hernia [3].
Mrs Marshall returned home and took some ibuprofen as advised and rested for the rest of the day. She went to bed at about 20.20 and at that stage was breathless as she went upstairs. In the morning she collapsed and an ambulance was called. She suffered a cardiac arrest and died.
It was agreed that had she been referred to hospital she would have been diagnosed as having a PE and the potential treatment options were anticoagulation [4] and/or thrombolysis [5].
The drug that would have been used for thrombolysis would have been alteplase which works by dissolving or removing any clots formed. This would have only have been used when indicated rather than automatically when the potential benefits outweigh the risks and in particular the risk of bleeding.
At the trial it was found that if the deceased been referred to hospital she would have received heparin [6] by 9.00pm on 25th April which would have taken effect to prevent further clotting by about midnight at the latest. Thereafter the arguments for each party were different.
Arguments at Trial
At trial it was argued on behalf of the claimant that had the deceased attended hospital, she would have had anticoagulant treatment and in that situation, it was unlikely that the massive PE that caused her death would have occurred. Even if it had occurred, she would have received thrombolysis and supportive treatment and on balance of probabilities would have survived.
The defendant argued that she would only have had less than 12 hours of full anticoagulation before she suffered the massive PE that caused her death. Heparin does not dissolve clot but stops propagation of the clot. It is likely that the clot which embolised on the morning was already present on the 25th. Failure to achieve stable full heparinisation within 24 hours of venous thromboembolism is associated with a 4-12 fold increased risk of recurrent pulmonary embolism. On balance of probabilities even had she been anticoagulated she would still have suffered the massive PE and died.
Decision of the court at trial
The judge first considered whether a specific chain of events could have saved Mrs Marshall. Having decided that he could not do so he then considered the statistical and other evidence to address causation. It was found that the claimant could not prove on balance of probabilities that Mrs Marshall would have been in the 64-75% who would have survived. She may not have been. Nevertheless, her chances of survival would have been significantly increased has she been in hospital overnight and at the time she became haemodynamically unstable.
The judge noted that the burden of proving causation lay with the Claimant, but that he needed do no more than prove that Mrs Marshall would probably have survived had she been admitted to hospital. The claimant did not need to prove the precise mechanism by which her survival would have been achieved. He noted that people did not die in hospital from PE and found in favour of the claimant.
The Appeal
The appeal by Dr Schembri was not successful and the Appeal court upheld the decision of Stewart J on the causation question and considered his approach was legitimate. He was correct to first consider whether the claimant had established a specific train of events that would have avoided the death. Having determined the question in the negative it was then legitimate for him to consider the statistical and other evidence and take a pragmatic and common sense view of the evidence as a whole including the statistical evidence.
Comment
The burden of proof in relation to causation questions rests with the claimant. The standard of proof is “balance of probabilities”. In this case and in many cases the court requires to address a hypothetical or “counter factual” situation.
It has always been accepted that a claimant does not need to prove the precise mechanism of harm, or of avoiding harm, to be able to succeed in proving causation [7]. On one view in this case there was sufficient evidence for the court to conclude that on balance of probabilities that the death would have been avoided but the court was not persuaded to do so.
There was a cross-appeal on behalf of the claimant that the court should have concluded that the deceased would have survived had she been in hospital. Ultimately this point did not require to be addressed but it does seem likely that the Appeal court would have been sympathetic to this argument.
What is of important in this decision is how “counter-factual” or hypothetical causation scenario (what would have happened as a matter of hypothetical fact had there not been a breach of duty) is to be addressed in circumstances when a precise mechanism that would have avoided the death cannot be ascertained.
The claimant’s argument was that where a claimant establishes a breach of duty of care and shows that the injury that follows it is of a kind likely to have resulted from a breach of that kind that is enough to enable him to succeed.
Reference was made to the decision in Drake v Harbour [8] Toulson LJ where it was said [9].
“In the absence of any positive evidence of breach of duty, merely to show that a claimant’s loss was consistent with a 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.”
In Schembri the likely result of the breach of duty was that the deceased would die from the pulmonary embolism in the absence of specialist treatment. In that situation the inference on causation is in the claimant’s favour. It was argued that the courts should not set too high a threshold for a claimant in such cases as the claimant is disadvantaged precisely as a result of the defendant’s breach of duty. The court should assess all the evidence as a whole to reach its conclusion applying a benevolent test to questions of causation.
[1] Marshall v Shembri [2019] EWHC 283 (QB)
[2] A pulmonary embolism is a blockage of an artery in the lungs by a substance, usually a clot, that has moved from elsewhere in the body through the bloodstream (embolism)
[3] A hiatus hernia is where the top part of the stomach slides upwards into the chest through an opening in the diaphragm
[4] Drugs used to treat blood clots
[5] The breakdown of clots using medication
[6] This is an anticoagulant that prevents the formation of further clots
[7] AXO v Salisbury NHS Foundation Trust [2019] EWHC 1454 (QB)
[8] [2008] EWCA Civ 25
[9] [28]