Expert evidence on life expectancy

May 26, 2021

Christopher Barnes

It is common in more sizeable personal injury and clinical negligence claims for defendants to seek to rely upon expert evidence as to life expectancy. If a claimant smokes, drinks or is obese, the argument goes, then his or her life expectancy must be compromised and it would be inappropriate to use a full multiplier when calculating future losses. With the potential size of some care packages and with the current negative discount rate (which serves to make costs at the end of life disproportionately expensive) even a small reduction can be of significance. Given the importance of the issue, it is worthwhile emphasising the principles that apply to an application for permission to adduce that evidence. They are neatly summarised by Master Davison in the case of Dodds v Arif [2020] PIQR P1 (N.B. his judgment has been cited with approval in the High Court on a number of occasions since – see Ellis v Kelly and Chaplin v Pistol):

  1. As detailed in the Explanatory Notes to the Ogden Tables, unless there is clear evidence in an individual case that the individual was atypical and would enjoy longer or shorter expectation of life, no further increase or reduction is required for mortality alone. Importantly, a claimant will not be “atypical” if they are a smoker or have a depressive illness (Edwards v Martin [2010] EWHC 570). Similarly, a claimant will not be atypical if they are a fit non-smoker with no particular health problems. In neither case would bespoke life expectancy evidence be justified. As noted in para. 12 of the 8th edition of the Ogden Tables:
    Whilst there is no definition of what constitutes atypical, the courts have generally been reluctant to admit expert evidence to argue for a different life expectancy solely on the basis of lifestyle factors, since the average in the Table includes smokers, non smokers, drinkers, teetotallers, people who are overweight and people who have an ideal BMI etc.
  1. If an injury has reduced the life expectancy of a claimant, that will potentially justify a departure from the norm. That can only be done with the aid of expert medical evidence.
  2. Life expectancy is a medical or clinical issue. In practical terms, it is more convenient and cost-effective to ask the clinical experts for their opinion on life expectancy. Even if recourse to statistics is required, then that material is still a matter for the clinicians in the first instance. It is only if they disagree on how to apply the statistics that a statistician or bespoke life expectancy expert might be required.
  3. Bespoke life expectancy evidence should be confined to cases where the clinical experts cannot offer an opinion at all, or where they have stated that they require specific input from a life expectancy expert.

Dodds is also of note in the consideration that was given to the defendant’s proposed expert, Professor Bowen Jones. He is almost ubiquitous and is the favoured expert for many defendants. He features in many of the reported cases and it is often said that, as a Physician, he is a clinical expert and, therefore, permissible. That argument was dismissed by Master Davison who noted that:

In the course of his submissions Mr Vincent pointed out that Professor Bowen Jones, whilst not a neurologist, is, nevertheless, a clinician. He was not offering mere statistics. He was offering an opinion on life expectancy which, whilst based on statistical methodology, was nevertheless tailored to the claimant’s case and her particular health profile. My view is that this submission does not meet the general objection to using a life expectancy expert as a “first port of call”. Professor Bowen Jones describes himself at page 3 of his report as a specialist in endocrinology and diabetes. These do not feature in this claimant’s presentation. His report is a desktop report and at page 10 he acknowledges that the method used is an actuarial method. It is apparent from his lengthy discussion of the various factors bearing on the claimant’s life expectancy (including her head injury) that his approach to these factors is primarily actuarial or statistical. I do not accept that his report can fairly be characterised as a report from a clinician, as that term has been used in the cases I have referred to. Further, to the extent that it could be so described, he is the wrong clinician. His specialism is as stated above when the appropriate clinician in this case would be a neurologist.

Finally, it is worthwhile emphasising that, once bespoke life expectancy is found to be appropriate, it is open to claimants to advance evidence that, pre-accident, they had a greater life expectancy than the norm (whether due to good health, a low BMI, a lack of smoking, area of the country in which they resided or whatever).