Earlier this month, Master Davison rejected a defendant’s application for permission to rely on ‘bespoke’ expert life expectancy evidence. This week, the Master handed down judgment, explaining why he prohibited reliance on Professor Bowen Jones at the case management conference.
Ordinarily, pre-condition life expectancy and the multipliers derived from life expectancy are taken from the Ogden Tables. Ogden life expectancy tables are designed to achieve ‘broad justice’ for personal injury cases and are based on a cohort affected by a variety of medical conditions, lifestyles and localities, as is explained by paragraphs 4 and 5 of the Explanatory Notes to the Tables (7th edition):
‘The tables are based on a reasonable estimate of the future mortality likely to be experienced by average members of the population alive today and are based on projected mortality rates for the United Kingdom as a whole …
The tables do not assume that the claimant dies after a period equating to the expectation of life, but take account of the possibilities that the claimant will live for different periods, e.g. die soon or live to be very old. The mortality assumptions relate to the general population of the United Kingdom. However, unless there is clear evidence in an individual case to support the view that the individual is atypical and will enjoy longer or shorter expectation of life, no further increase or reduction is required for mortality alone’.
When can the Ogden Tables not be trusted?
Typically, ‘bespoke’ expert evidence on life expectancy is not permitted unless a claimant is ‘atypical’, which refers to:
‘... outliers from the population cohort comprised in the Tables who, because of special factors relating to their general health, could be expected to enjoy longer or shorter life expectation’.
In this particular case, the claimant was suffering from a traumatic brain injury, but Master Davison’s decision applies to all personal injury claims.
The claimant had obtained expert medical reports from a neurologist and a geriatrician, both of whom addressed her symptoms. The expert neurologist concluded that, unless the claimant developed epilepsy (there was a 5% risk), her life expectancy was ‘unlikely to be significantly reduced’.
The defendant disclosed their own report, which had been produced by Professor Jones. They did so ‘without first canvassing the instruction with the claimant’, as is encouraged by the Pre-Action Protocol. As a specialist in life expectancy, he applied ‘The Rating of Substandard Lives’ method, otherwise known as the ‘Brackenbridge’ method, and adjusted the claimant's pre- and post-accident life expectancies downwards from the ‘Ogden predictions’.
The claimant resisted the defendant’s application for permission to rely on ‘bespoke’ life expectancy evidence, on the basis that she was not ‘atypical’ and that clinical experts were best suited to address the issue.
Firstly, Master Davison deemed that life expectancy evidence was required, pursuant to CPR 35.1, because the claimant’s head injury had had an ‘impact on her life expectancy’. Whether or not the claimant was ‘atypical’ was therefore irrelevant.
Having established that evidence was required, it was necessary to determine whether this had to be ‘bespoke’. On this issue, he found in favour of the claimant.
Life expectancy has traditionally been viewed as a ‘medical, or clinical, issue’. By contrast, statistical evidence, which forms the basis of a life expectancy expert’s assessment, is only a ‘useful starting point’, or ‘no more than a starting point’.
Professor Bowen’s report could not be characterised as a report from a clinician. Although he was a clinician, he was not a neurologist and was therefore the ‘wrong’ type of clinician. He also acknowledged that his approach was ‘primarily actuarial or statistical’.
The Master went on, at paragraph 18 of his judgment, to reason that:
‘... it is usually very much more convenient and cost-effective to ask the clinical experts for their opinion on life expectancy. They will already be instructed and can deal with life expectancy together with the other matters they are concerned with (in this case the claimant's cognition and other neurological problems). It is commonplace for clinical experts to express their opinion as to life expectancy by reference to a reduction from the Ogden Tables average – sometimes called a "top-down" approach. This is a clear and accessible method which, if adopted, makes the choice of a suitable multiplier a simple matter. It is certainly not in every case that recourse (or further recourse) to statistics is required. But if it is, then such material is still, in the first instance, a matter for the clinicians and it is only in the case where they disagree on how to apply the statistics that an expert such as Professor Bowen Jones might be required. A further factor pointing in favour of the clinical experts and against bespoke life expectancy experts is that the latter are in very short supply. If it became a frequent practice to instruct them, then that would have the effect of introducing delay as well as considerable extra cost – to no great advantage’.
Despite highlighting what is ‘commonplace’ clinical expert practice, Master Davison clarified that it ‘is not for the court to dictate’ how an expert arrives at their opinion. An expert has a ‘clean sheet’:
‘(S)he may use a "top down" approach, which starts with the Ogden Tables and discounts as appropriate or a "bottom up" approach which starts with the impact of the injury’.
So, when is ‘bespoke’ life expectancy evidence required? The Judge concluded that:
‘... [it] 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’.
The decision was helpfully summarised by the following propositions:
Full text judgment can be accessed here.