Even if this evidence was reliable, in order to form a rational belief as to whether the claimant’s disease could have been successfully treated it is essential to personalise it to the individual as far as possible. Professor Goldstone had made some attempt to personalise the statistics to Mr Gregg’s post-tort chances in light of the progress of his treatment, suggesting that the likelihood of survival had increased from 10-15% at the time of diagnosis to 20-30% at the time of trial. But there was no corresponding attempt to personalise the statistics in relation to his pre-tort chance of survival despite there being information on which this attempt could have been based. Stapleton explains this argument:
The unpersonalized estimate of [Mr Gregg’s pre-tort chance of being cured] was 42%. But by the time of trial we had an important piece of information about the actual experience of this particular claimant after the commencement of treatment, which could have been used to “personalize” that estimate. By the trial we knew that, even after breach, Mr Gregg was able to achieve complete remission in 1996. Does this not show that, a fortiori, had there been no breach, Mr Gregg would have been one of the 59 out of
80 Gregg (CA) (n28) [11].
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100 who initially achieved complete remission? A member of that group had a pre-tort chance of cure of 42/59 = 71%, not 42%.81
It was noted above that it was assumed that Professor Goldstone’s working example applied to a cohort of 100 patients whose disease was at the same stage as the claimant’s pre-tort disease, and that he did not provide a similar working example for 100 patients whose disease was at the more advanced stage that Mr Gregg’s cancer had reached when treatment commenced. It is thus unclear where the assessment of the claimant’s post-tort likelihood of cure at 10%-15% was derived from. Furthermore, Lord Phillips questioned this assumption, explaining ‘[w]hen describing Professor Goldstone’s model, the judge stated: “The 100 patients in the worked example include all ages, and also people with other unrevealed personal characteristics, one of
which is the stage of the disease at diagnosis”’.82 This means that the court could have made some
attempt to personalise the statistics by considering the claimant’s age, and the stage of his disease. Surely, given the early stage of his disease he was more likely to belong to the survivor category than somebody whose disease is more advanced?
So in any negligence action the court must seek to personalise the evidence to the individual claimant in order to form a rational belief in the likely causes of the damage, and should also evaluate the reliability of the evidence. Mr Gregg’s claim would have been hindered because he had not suffered actionable damage in the form of the final outcome, and because the evidence pertaining to causation had not been personalised and in any case was not reliable. It seems unlikely that he would have been able to prove causation on the balance of probabilities even if he had suffered actionable damage, but there is nothing to suggest that this is a particularly unusual problem requiring an exceptional solution. The claimant’s argument was that the application of conventional principles resulted in an unfair failure of his claim, so exceptionally fairness demanded that the loss of a chance of a better outcome should be substituted as the gist of the action. This section has demonstrated that there were no inherent obstacles to proof of
81 Stapleton, ‘Loss of the chance of cure’ (n10) 1000. 82 Gregg (HL) (n26) [148].
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causation that would have made rejection of his claim ‘unfair’, it is simply that the evidence in his case was weak, so there seems to be no reason why ‘fairness’ should have a claim on the law in preference to corrective justice. The next section turns to the notion of ‘chance’ itself to consider whether it could form the gist of a negligence action if fairness so required.
4. ‘Loss of a chance’ as damage
In this section it will be argued that in the context of medical negligence, specifically the misdiagnosis or mistreatment of an existing illness, the loss of a chance ought to be recognised as damage that can form the gist of a negligence action. Instead of approaching the question of loss of a chance as a way of assisting a claimant who faces difficulties of proof of causation, however, the issue will be approached from the perspective of whether a lost chance can constitute actionable damage. This means that ‘chance’ will be examined in its own right, rather than as leading to recovery of damages that are proportional to the physical harm to which the chance relates. In other words, it will be argued that a lost chance is a distinct form of damage that ought to have a place in the tariff set out in the Judicial College’s Guidelines for the Assessment
of General Damages in Personal Injury Cases.83 This will therefore continue to develop the argument
that the issues of damage, causation and quantification are three distinct issues, and that clarity in the law can only be achieved by having a full understanding of the content and role of each concept and the interrelationship of the three.
This section will begin by addressing the concept of chance in order to demonstrate that, in the limited context of medical misdiagnosis/mistreatment of existing illness, a ‘chance’ is something of value that can be lost and ought to be recognised as being an actionable form of damage. There is a unique relationship between doctor and patient when treating an existing illness since the outcome of treatment is uncertain for both, meaning that both parties value the patient’s chance of being cured. As argued in Chapter One, these issues of interpersonal responsibility
83 Judicial College, Guidelines for the Assessment of General Damages in Personal Injury Cases (11th ed., Oxford University
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present in the doctor’s duty of care should be allowed to shape the negligence inquiry so that loss of a chance can be recognised as damage. This is consistent with a corrective justice based approach to negligence which requires the defendant to repair wrongful loss that he caused. An important aspect of recognising loss of chance as actionable damage is the argument that the concept of the loss of a chance is distinct from the concept of an increase in risk, so recognition of claims for loss of a chance in this limited context would not have the expansionary effect that is often feared.84 Finally the issue of valuing this chance will be addressed in order to show that
since the chance is a distinct loss its value is independent of the final harm that the patient wishes to avoid. It will be clear that loss of a chance is not being presented as a solution to a problem of causation, and that this in turn will lend clarity to future causal problems in medical negligence.