Life Expectancy in Cerebral Palsy cases: The mechanism behind the crystal ball

The determination of life expectation in cerebral palsy litigation must always be driven by the expert evidence in the particular case.

What is set out below is an approach driven by the evidence received from experts in reported decisions, but – be warned – great care must always be taken to ensure that in each case the court has available to it up to date (i) literature and (ii) experienced clinical expert views specific to the particular claimant.

The key High Court cases which have considered life expectancy in cerebral palsy cases are Whiten v St George’s Healthcare NHS Trust [2011] EWHC 2066 (QB) and Robshaw v United Lincolnshire Hospitals NHS Trust [2015] EWHC 923 (QB).  At the invitation of both sides’ experts in those cases the courts relied on Strauss data. (The latest version of this data – and its  analysis – can be found in Brooks JC, Strauss DJ, Shavelle RM, Tran LM, Rosenbloom L, Wu YW “Recent trends in cerebral palsy survival. Part II: Individual survival prognosis.” Developmental Medicine & Child Neurology, (2014) 56:1065-1071 [“Brooks (2014)”] which can be found along with a plethora of useful articles and commentary on the excellent Life Expectancy Project website.

Having assessed the expert evidence, the first instance judges in both Whiten and Robshaw adopted the following three stage approach (please note – a worked example is included at the end of this article). I should stress that not all experts will agree with this three stage approach or methodology.

Stage 1: Use US/Californian Strauss data to obtain the general life expectancy for a child of the age and disability of the claimant in question.

Depending on age this can be done solely through Table III of Brooks 2014 or by a combination of Table II (table for life expectancy from age 4) and Table III (cohorts from the age of 15 upwards).

In Robshaw given the age of the claimant a small reduction was applied by the defendant’s expert to allow for the risk of mortality pre-15 (the claimant was aged 7 at the time of assessment).

Stage 2: Then uplift that general life expectancy to allow for the higher projected UK life expectancy figures which are used in UK cases.

Both Whiten and Robshaw accepted this approach which derives from Strauss et al “Life expectancy in cerebral palsy: an update”, Developmental Medicine & Child Neurology, (2008) 50: 487–493 at 491 (see the worked example below).

Stage 3: After this, the specific features in the particular case are assessed to determine whether there should be any addition or reduction in that life expectancy.  The deduction or addition is made after stage 2.

In Whiten the approach of making deductions or additions after the uplift was adopted. [§22] On the facts in Whiten no change was made from the general life expectancy.

In Robshaw Foskett J stated:

  1. the “onus of persuading another court that the approach in Whiten is wrong must lie on those instructed by the Defendant in a subsequent case.” [§99]
  2. “it seems to me more logical to alight upon a sensible starting-point and then to adjust the predicted life expectancy to reflect individual factors thereafter, particularly if some of the factors reflect the effect upon life expectancy of future changes of the individual circumstances.” [§87]
  3. “there seems to me some logic in the proposition that in a case such as this the Strauss figures should be converted to the projected life expectancy in the UK to the result of which any adjustments in the light of UK experience and/or conditions should then be made because it will be that experience that will inform the assessment of the individual living in the UK and those conditions in which the individual claimant will live and be cared for.” [§100]

Whilst this approach is disputed by some experts, the expert views in Robshaw led the court to determine that in assessing those individual factors it is appropriate to take into account the benefit to the claimant of being provided with a high standard of care based on the damages they are about to receive.  In Robshaw Foskett J added an additional 2 years for “the quality of the future care and the lifestyle” [§132] having noted the following:

“I do not see why the court cannot, in an individual case, seek to identify the risks that exist in an individual’s life if he or she is a cerebral palsy patient and then consider the life that such a patient is likely to lead in the future and to determine how large those risks in truth are likely to be in that individual’s life. In some cases, of course, the best care in the world may not obviate or materially reduce those risks. But there may be other cases in which it is quite plain that the risks to life are reduced by the quality of care to be received and if that can be demonstrated as the likely scenario I cannot see any reason in logic for the court not giving effect to that conclusion in the individual case by adjusting the life expectancy thrown up in the generality of cases based upon the available statistics.”

Robshaw cited Owen v Brown [2002] EWHC 1135 (QB) noting it took:

 “account the guidance given by the Court of Appeal in The Royal Victoria Infirmary and Associated Hospitals NHS Trust v. B (A Child) [2002] EWCA Civ 348, an important case in this context, Silber J said this [88]: “….I strongly agree…a significant positive factor that [was] correctly [taken] into account was and is the very high standard of care that the claimant receives and will receive. The effect of the award in this case is that the claimant will be the beneficiary of very high quality care in all the areas in which he requires it.” [§119]

Further a similar approach had been adopted in Sarwar v Ali and the MIB [2007] EWHC 274 (QB) and  Burton v Kingsbury [2007] EWHC 2091 (QB) [§120-121]


Three further points are worth noting.

First, Strauss data was adopted in Whiten and Robshaw because this was the preferred approach of the experts before the court. Other experts may take a completely different approach. Some may reject Strauss entirely; for example, by arguing (i) that the Strauss data is too difficult to apply consistently because it does not adopt a standard classifications such as the Gross Motor Function Classification System (“GMFCS”) and different health systems and doctors may have different thresholds for prescribing tube feeding (one of the key Strauss criteria), or (ii) the data is too out of date to be used for estimations today as care for those with cerebral palsy has improved vastly in recent years, or (iii) quite simply the Californian experience just cannot be transposed to the contemporary UK context.

Alternatively other experts may choose to fold the Strauss data into a wider consideration of information available from other sources in the literature and their own clinical experience.  A comprehensive review of the key available papers including a proposed approach to the analysis of the respective underlying data is set out in Plover, Life expectancies for individuals with cerebral palsy (2019) (It remains to be seen whether experts or the courts will consider applying the detailed life expectancies for each age generated by Plover’s approach at Tables B to J in this actuarial analysis – which has not yet appeared in a peer-reviewed journal – or whether they will be seen as an extrapolation too far).

Second, great care should be taken to ensure the court is provided with the most up to date and comprehensive view as possible on a cerebral palsy claimant’s condition. If the Strauss data is to be used a lot turns on precise aspects of a person’s condition (for example can they lift their head or chest). It is therefore important that not only paediatric neurology experts comment on the condition but that also information is obtained from the family and from other experts – in particular treating and medico-legal physiotherapists – all of which can then feed into that paediatric neurology assessment.  If there is a dispute between the experts about the extent of someone’s disability, a court may also be assisted by video evidence.

Third, returning to the three stage approach to Strauss set out above, different  experts may adopt different methods for the calculation of life expectancy of those under 15. Table II addresses children aged 4 to 15.  Table III then provides data for those 15 and above. One suggested approach – especially for those closer to age 4 than 15 – is to assume a linear reduction in life expectancy throughout the period from age 4 to 15 then apply that to reduce the years of life in that period but then use table III to assess the life expectancy thereafter.

This is best illustrated with a worked example. Suppose a male cerebral palsy child aged 8 who can lift their head and chest and is tube fed. Table II indicates a probability of a male child with this type of debility aged 4 surviving to age 15 of 71%, that is a mortality of 29%.

Assuming a linear reduction in life expectancy this equates to a 2.6% p.a. reduction (29% divided by 11), which in turn over 7 years equates to 18.5% (7 x 2.6%). 18.5% of 7 years is a 1.29 year reduction.

One then turns to Table III to assess the position assuming the child reaches the age of 15: this indicates an additional 18 years’ life expectancy; that is until aged 33 when the general Californian population life expectancy at the time was 76.4 (15 + 61.4).

But it is necessary to allow for the chance of not reaching age 15 which based on the initial Table II calculation implies a 1.29 year reduction giving a further 16.71 years (18 minus 1.29) and a survival until aged 31.7 (15 + 16.71). That concludes the suggested stage 1 Strauss analysis.

Stage 2 requires an uplift to provide a UK projected life expectancy. Current Ogden life expectancy for a male aged 8 is a further 79.6 years to age 87.63. Life expectancy of the Strauss general population is 76.4 or a further 61.4 years. A further 16.71 years from aged 15 represents 27% of that general population figure (16.71 divided by 61.4). 27% of the further years of the UK population from aged 15 is a further 19.8 years (27% x 72.63) and hence a life expectancy to about age 35 (the overly precise calculation is to 34.8). Stage 3 would then require consideration of the specific factors in the individual case which reduce or increase that general life expectancy figure.

All of this must be set out with a warning in bold flashing letters that “other methodologies are available”.