Monday, 19 November 2012

Proving Reduced Life Expectancy after Delay in Diagnosing Cancer

A recent High Court decision underlines the importance of using median life expectancy to prove loss in cases of delay in diagnosing cancer.

If a claimant's GP has been negligent in failing to refer them for investigation for  a suspected cancer, and as a result there has been a delay in diagnosis with a resultant delay in commencing treatment, then there are likely to be various kinds of injury to consider. The delay may have lead to more radical or extensive treatment being required: for example the patient might need a mastectomy rather than a lumpectomy. They might require adjuvant treatment when, without the delay, surgery alone may have sufficed. The patient might have suffered psychiatric injury as a result of the delay. But many patients/claimants are most concerned about the effect of the delay on their life expectancy.

Oncologists tend not to advise their patients in terms of years of life expectancy. They do not say that evidence shows that median life expectancy for someone with a T1N1M0 tumour is 8.5 years. Rather, they talk of the chances of a cure, or of survival beyond 5 or 10 years. Gregg-v-Scott [2005] 2AC 176 established that there is no valid claim for a reduced chance of a cure. So there was no compensation for delay which reduced the chance of a cure (survival beyond 10 years) from 42% to 25%.

However, two of the judges in the House of Lords in Gregg-v-Scott , described how the impact of negligent delay in diagnosis on life expectancy might have been argued. It might have been possible to assess the claimant's median life expectancy (MLE) without the delay, and compare that with his MLE as it was in fact (following the delay). The difference - a number a months or years - would be the loss. That approach might allow for calculation of a claim for loss of earnings in "the lost years", for example. In a fatal case, a difference in MLE without delayed diagnosis, and the date of actual death might allow for calculation of a period of dependency.

MLE is the period of time for which 50% of patients with the same grade, stage and size of tumour as the claimant will live, given the treatment which the claimant ought to have had on earlier diagnosis (or which he had following actual diagnosis). On the balance of probabilities the claimant will live (or would have lived) at least as long as MLE. On the balance of probabilities he will not live (or would not have lived) any longer.
In the recent decision of JD-v-Mather [2012]EWHC 3063 (QB) Bean J held that the evidence showed that even without the negligent delay the claimant's chances of survival for at least 10 years were below 50% and that therefore, following Gregg-v-Scott, the claimant's principal and pleaded claim failed. However, an alternative case had been brought, late in the day, that the delay had caused a reduction in MLE. That claim succeeded.

It is a question of how the evidence is presented. In some cases of mine, expert evidence has been obtained for medical statisticians.

The use of MLE to prove a reduction in life expectancy will not work in every case. It helps if the cancer is one for which there is sufficient data to allow for a "calculation" of MLE. Of course every patient is an individual, but statistical evidence is surely of great assistance in such cases (as Bean J found). Just because a patient had a less than 50% chance of survival for at least 10 years even without the negligent delay, it does not follow that their life expectancy has not been reduced by the delay. The use of MLE allows the reduction to be established.

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