Toby Chaplin (by his mother and litigation friend, Diane Chaplin) v Ben Pistol, Allianz Insurance Plc [2020] EWHC 1543 (QB),2020 WL 03254432

Key Points

Mr Justice Jay explored the admissibility of evidence from medical statisticians as to life expectancy under CPR 35.1. The Court re-affirmed the principle that statistical evidence will be reasonably required only where the medical experts:

(i) cannot express a view on life expectancy;

(ii) expressly state that such input from a medical statistician is needed; or

(iii) disagree as to the application of available statistics.

This case is also a useful reminder to us all of the importance of prompt action by a party who is unhappy with a court direction. A party will be deemed to accept a direction if they do not appeal it within 14 days of the order being made and will be unable to revisit the issue by way of a later application unless circumstances have changed. (CPR29 PD6)

The burden will be on the party applying to show the change in circumstances.


At 28, the Claimant had acquired a traumatic brain injury and been rendered tetraplegic in an accident caused by the negligent driving of the Defendant. The case came before Master Eastman in July 2019 for case management. At that stage, it was common ground between the experts in neurology for each party that the Claimant’s injuries had significantly reduced his life expectancy. However, they disagreed as to the extent of the reduction, Dr Liu for the Claimant estimating that his life expectancy to be 30-35% of normal; Professor Collin for the Defendant adopting a figure of 30-44% of normal. There were also differences in the experts’ approach to available statistics. Whilst the range of figures adopted by each expert were not far apart and it was likely that the Claimant’s care costs would by awarded by way of a PPO, it was nonetheless accepted that the difference between the parties translated to a 7-figure sum. At the CMC before Master Eastman in July 2019, the Defendant’s application for permission to rely on a report, from medical statisticians on the issue of the Claimant’s life expectancy, was dismissed on the basis that neither party’s neurology expert deferred to evidence from a statistician to assist them in determining the Claimant’s life-expectancy and such evidence would not add to their existing analysis of the available statistics. The Defendant did not appeal.

At a hearing almost one year later, Mr Justice Jay considered the Defendant’s further application, dated 21st May 2020, to admit the evidence from the medical statisticians. By the date of the hearing of the application in June 2020, the neurology experts had revised their opinions as to the Claimant’s life expectancy, Dr Liu for the Claimant estimating the range to be 35-40% of normal; Professor Collin for the Defendant adopting a figure of 30-35% of normal.

The Defendant’s application was opposed by the Claimant on grounds that the Defendant had not appealed the dismissal of his first application and the circumstances had not changed sufficiently to justify the Court re-visiting the issue at this stage. A JSM was imminent and the trial of the action was to take place in October 2020, admission of the evidence at this late stage would jeopardise the trial date as the Claimant would need to review the statistics admitted which were, as yet, unpublished.

Judgment of Mr Justice Jay

  • Pursuant to CPR29 PD6, a party aggrieved by a court order must either appeal it or demonstrate a relevant or sufficient change in circumstances since it was made on a further application.
  • Professor Collin, instructed by the Defendant, had stated in her recent report that, “if the Court requires an accurate estimate based on more detailed stratification of the survival data, then it would be extremely helpful if the Life Expectancy Project authors…could be approached to provide this greater detail.” However, Professor Collin could have said that in her earlier report dated March 2019 or in a letter before the CMC in July 2019. No change in circumstances had taken place in the intervening period.
  • The statistical evidence on which the proposed evidence of the medical statisticians was based was unpublished material. If admitted, the large measure of methodological consensus achieved by the neurological experts would be fundamentally and radically upset. This was as much the case at the time of the earlier application as it was at the time of the application dated May 2020, thus nothing had changed.
  • Since the Defendant did not appeal the original case management decision refusing permission to rely on the statistician’s evidence and considering that there has been no relevant or sufficient change in circumstances, his application would be dismissed.
  • In any event, the evidence is not reasonably required for the purposes of CPR r.35.1. Evidence from a medical statistician is, in principle, admissible although ordinarily it should be seen as the starting point for the clinical judgments made by medical witnesses. Medical experts are usually well able to apply and interpret quite complex statistical evidence without the need to call probative or explanatory evidence.
  • As summarised in Dodds v Arif [2019] EWHC 1512 (QB), bespoke life expectancy evidence should be confined to cases where the relevant clinical experts cannot offer an opinion at all or state that they require specific input from a life expectancy expert or where they deploy, or wish to deploy statistical material, but disagree on the correct approach to it.
  • Whilst Professor Collin commented that input form a medical statistician would be desirable as it would give the Court greater confidence in its conclusions, courts are well used to deciding cases on the basis of evidence which is adequate but not optimal.
  • Late applications should be determined in line with the overriding objective and there are powerful reasons to preserve the imminent trial date. If the evidence of Professor Strauss was admitted, the Claimant would be entitled to have it subjected to appropriate scrutiny by an expert in medical statistics and there would be an unacceptable jeopardy to the trial date.