Causation in stroke case
Mr Hooper, a self-employed businessman aged 50, felt unwell at work on 18 July 2011. He was taken home by a colleague and his wife called an ambulance. He was admitted to Basildon Hospital at 13.04. The attending doctor thought he had suffered a transient ischaemic attack (TIA). Later that afternoon Mr Hooper was discharged home. The following day he had a stroke.
Before trial the trust made a number of admissions, including that Mr Hooper should have been assessed as a high risk patient, admitted on 18 July and kept under observation, and been prescribed 300mg of aspirin that day. He should have undergone a CT or MRI scan on the morning of 19 July and would have been in hospital when the stroke occurred. However, the defence argued that stroke would still have happened and therefore the claimant had not suffered any detriment as a consequence of the admitted negligence.
The main implication of a TIA is that the patient is at risk of an early stroke. Aspirin prevents platelet cells forming a blood clot and thus can stop a stroke from occurring.
A medical expert instructed on behalf of the claimant initially accepted that there was no scientific evidence to support the view that immediate use of aspirin would have prevented the stroke. However he was referred to a leading authority, Professor Rothwell, who whilst initially agreeing with that proposition based on published studies, then re-analysed data and came to the conclusion that Aspirin substantially reduced the risk of stroke within the first 24 hours. He expressed this opinion in an email to the claimant’s expert. This view was disputed by the trust’s expert, hence our defence of this claim.
The respective experts were of equivalent clinical experience. However, Professor Rothwell was not called to give evidence by the claimant’s legal team and had indicated that he did not wish to become involved in medico-legal matters. He had published a paper in May 2016 which was an analysis of previous academic studies. There was no indication the professor knew that his email might be cited in court, and its conclusions had not been subject to peer review. Professor Rothwell had emphasised that the 12 trials considered in his paper were not of hyperacute cases. He had not been informed of all the facts surrounding the present case and therefore had not been able to take them into account.
The Rothwell paper lent strong support to the use of aspirin in stroke cases but not to its efficacy within 24 hours. Ultimately the claimant’s expert had accepted in court that “I can’t give you evidence that proves for certain on the balance of probability that less than 24 hours is effective”. Consequently, having regard to the totality of the evidence, the claimant had not established on the balance of probabilities that aspirin would have prevented his stroke. That stroke would have happened in any event. Although certain academic writers had demonstrated some benefit from this medication in the first day following a TIA, that was not sufficient to discharge the burden. Similarly there was no evidence that aspirin would have ameliorated the effects. The claim therefore failed.
This was a sad case where a comparatively young man suffered life-changing disability. There had undoubtedly been negligence during the first hospital attendance and that was admitted. The claim turned upon expert causation evidence. Professor Rothwell’s paper and email have been used to support a number of claims, but need to be analysed carefully and in the present case it was unfortunate that his email was used as the basis for a causation argument when the professor did not have the benefit of full details of the claim in order to refine his opinion. A number of clinical negligence claims turn upon the assessment of academic papers, and this ruling demonstrates how careful the parties must be in deploying such evidence. Full understanding of its implications is essential.