Having said that, even accounting for the momentum from cases like Fairchild v Glenhaven Funeral Services Ltd and Chester v Afshar, it appears as though the judiciary are unwilling to take that giant leap forward, as they could have done in Gregg v Scott. These three cases show how the horizons of causation have been broadened from the formulaic ‘but for’ test and yet steps remain to be taken to compensate those who have been injured through neglect of a duty.
An exercise in semantics?
For our purposes, the first quantum leap in causation principles comes from Fairchild. This is a case where three applicants claimed that a number of previous employers had, in turn, exposed them to cancer causing asbestos dust. The causal problems arise when one realises that asbestos definitely created their cancer but, without knowing which employer actually exposed them to the specific fibre that caused their disease, they could not claim for their damages. Lord Bingham makes it clear when he says: ‘there is no way of identifying, even on a balance of probabilities, the source of the fibre or fibres which initiated the genetic process which culminated in the malignant tumour.’ Traditional causation is based on the ‘but for’ test, which is an exercise in semantics that weighs the likelihood of negligence having caused injury on the balance of probability. Fairchild is special because, as some learned practitioners suggest, ‘the “but for” rule, which was evolved in days of litigation over cattle trespass, fire and flood, is not surprisingly too crude a tool to provide a just solution in the context of litigation involving the complex causation of disease, where there have been successive employments and where there is no clear scientific evidence as to causation’. Consequently, the decision is one that allowed a break from tradition, namely the ‘but for’ test, through a test where ‘material contribution’ to risk was sufficient for proving causation. It should also be noted that this is an instance where the House decided to hold defendants strictly to their duty, despite difficulties with proving causation. The second leap comes from Chester v Afshar, where Miss Chester went to Doctor Afshar for surgery on her spine. During the consultation, Afshar failed to mention a small risk of nerve damage from the proposed surgery. After the procedure, the very injury that Afshar had failed to warn Chester about had eventuated. Their Lordships expressly decided to compensate Chester with a ‘modest departure from traditional causation principles’, asserting that ‘the breach of the surgeon resulted in the very injury about which the claimant was entitled to be warned’. This does not show that the breach caused the injury. In the words of Lord Hope: ‘on policy grounds, therefore, I would hold that the test of causation is satisfied in this case.’ Consequently, the ‘but for your actions, it is more likely than not I would not have suffered my injury’ test is jettisoned in order to make it possible for a claimant to recover, even though there is no factual possibility that a failure to warn caused the injury, nor did it materially contribute to the risks of surgery. Chester makes causation an issue of policy and duty.
Patient autonomy
There are academics who believe that the House could have ‘afforded the remedy’ which Miss Chester sought by using traditional principles of causation. Stapleton asserts that ‘it would have been more likely than not that, but for the breach, [Miss Chester] would not have suffered the syndrome’ because her chances of being injured on a subsequent date would also only have been one to two per cent. This position, respectfully, over-simplifies the idea that a small change in time or events would have prevented the injury, an argument Lord Hoffmann cites in his dissent.

Their Lordships have simply decided that a patient’s autonomy and right to make informed decisions must never be violated. This is a noble decision that prioritises observance of duty over the ‘crude tool’ that is the ‘but for’ test. Gregg v Scott conversely shows that their Lordships don’t want to apply their altered principles and move towards a next generation of causation. In this case, Doctor Scott negligently misdiagnosed a lump in Mr Gregg’s armpit that turned out to be cancerous. Gregg sued on the basis that the negligent misdiagnosis had reduced his chances for disease free survival for ten years from 42% to 25%. Lord Neuberger explains the decision by saying: ‘the claimant should not be compensated, as the simple fact was that, on the balance of probabilities, the claimant was not going to survive for ten years whether or not he had the treatment.’ In the judgment, the traditional principle that ‘on the balance of probabilities that what the defendant negligently did or failed to do caused the claimant’s damage’, is rigorously applied. In Gregg, the defendant, it is submitted, did cause the claimant’s damage, namely his diminution of a chance of disease-free survival, but respectfully, their Lordships won’t use the modified causation principles developed in Chester and Fairchild, because Mr Gregg has not died. Baroness Hale goes on to say: ‘what, if anything, has the doctor’s negligence caused in this case? We certainly do not know whether it has caused this outcome, because happily Mr Gregg has survived each of the significant milestones along the way.’ Since his chances before surgery were, on a balance of probabilities, null, he lost nothing by negligence.
Vindication of rights
The new regime of causation principles should be strongly in favour of holding professionals to their duty. Some ask, ‘Why should the “right” to decide whether to accept treatment be accorded greater protection and value by the law than the logically and chronologically prior right to be told that such treatment is available and could be beneficial?’ It is submitted that Fairchild and Chester do make it possible for Gregg’s ‘right’ to be vindicated provided causation is framed in terms of a dangerous breach of duty; and policy demands it. This truly would be the final frontier for these modified principles of causation.

Jim Kapches is in the third year of a Law LLB