Life expectancy and expert evidence in the field of medical statistics

Chaplin v Pistol and another [2020] EWHC 1543 (QB), Mr Justice Jay, 16/06/2020

Reduced life expectancy is a common feature of industrial disease cases.  However, it is usually the case that medical experts are able to determine the same.  In the case of Chaplin the matter of expert evidence in the field of medical statistics in relation to life expectancy was considered.  This has general application to personal injury cases including industrial disease practitioners.  

The facts of this case involved a claimant who had suffered a very severe traumatic brain injury with tetraplegia and whose life expectancy has been significantly reduced. 

Although care would be met by the means of a periodical payments order, other head of loss would be determined using traditional multipliers and the Judge accepted that a seven-figure sum rides on the issue in this case. 

The Defendants’ application was made in May 2020, but they had been a previous application in July 2019 when the Defendants had sought permission to rely on expert evidence in the same field and from the same proposed expert.

Each party in this case had obtained neurological evidence and each party’s expert had commented on life expectancy.  The judgment includes an analysis of how each expert came to their views based upon a variety of academic papers in relation to the particular case.

The Judge considered the content and submissions made at the previous application in July 2019 and noted that the statistical evidence sought to reduce the percentage figure that both parties’ neurological experts had made in relation to life expectancy.  

The Judge considered the Note of that earlier hearing where the judge had said “neither experts seek to defer their opinion to anyone else and the evidence is not necessarily appropriate”.  

There was no appeal from that decision.  

At this application the Defendants submitted that things had moved on in relation to the evidence relied upon and therefore the Court was at liberty to determine the matter afresh.  Ultimately the Judge agreed with the Claimant however that there had not been a sufficiently ‘relevant and sufficient’ change in circumstances for the application to be considered again.

However, the Judge then gave Judgment if there had been no previous decision and therefore considered the application on the merits itself as to whether it was ‘reasonably required’ under CPR r35.1.

The Judge considered the case of Royal Victoria Infirmary v B [2002] EWCA Civ 348 noting that evidence from a medical statistician is, in principle, admissible.  However, he noted that medical statistics usually provide the starting point for clinical judgments made by the medical experts.  He commented that medical experts are usually well able to apply and interpret quite complex statistical evidence (especially if peer reviewed) which can be admitted as hearsay without the need to call probative or explanatory evidence.

The Judge also considered the judgment of Master Davison in Dodds v Arif [2019] EWHC 1512 (QB) and considered that his view of the authorities was correct when he set out:

“For these reasons, it seems to me that bespoke life expectancy evidence from an expert in that field 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 (see e.g. Mays v Drive Force (UK) Limited [2019] EWHC 5), or where they deploy, or wish to deploy statistical material, but disagree on the correct approach to it. This case does not, or does not yet, fall into any of these categories.” 

It should be noted that such permission had been granted in Mays.

The Judge commented that in the case in hand the neurological experts had expressed themselves able ‘without qualification or equivocation’ to proffer evidence on life expectancy.  The Judge commented that the courts are well used to deciding cases on the basis of evidence which is adequate but not optimal.  In this particular case the evidence may undermine both parties’ neurological evidence and therefore reliance upon it should have been indicated at an earlier stage in litigation. 

The Judge confirmed that had he been dealing with the case in July 2019 he would have also not allowed the expert statistical evidence to be relied upon.

Finally, the Judge stated that even in the event that the change of circumstance was ‘relevant and sufficient’, the application would fail in any event.

On the facts of this case it appeared that the probable loss of the trial date (October 2020) would override any consideration of allowing the new evidence to be relied upon, and it would result in counter-evidence being sought, the July JSM being adjourned and dates for Schedules and Counter-Schedules pushed back.  

This case is authority for:

  1. Life expectancy statistical evidence is in principle admissible.
  2. However, medical statistics usually provide the starting point for clinical judgments made by the medical experts.
  3. Per Master Davison: “Bespoke life expectancy evidence from an expert in the field 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.”.
  4. Any such application needs to be made at a stage before the medical experts had committed themselves to their conclusions as to life expectancy.