TY - JOUR
AU1 - Purshouse, Craig
AB - Anyone who has glanced at the law reports recently will share Gemma Turton’s view that ‘the approaches of courts and academics to the doctrine of causation have become increasingly complicated and confused’ (p 1). Evidential Uncertainty in Causation in Negligence aims to rectify this and will, therefore, be of interest to readers of the Medical Law Review. After all, many of the leading appellate cases on causation have arisen in the clinical setting. Unlike in, say, a running-down case where a healthy person is left with a broken arm, the claimant in a clinical negligence case will usually already be ill before they have had any contact with a careless healthcare professional. Thus, there will be (at least) two possible causes of the patient’s damage: the doctor’s breach of duty and the patient’s original condition. This makes it difficult to attribute the claimant’s damage to the defendant’s wrongdoing. The normal way of determining whether a defendant’s breach of duty has caused the claimant’s injury is the ‘but for’ test. This requires the claimant to demonstrate that but for the defendant’s breach of duty of care he or she would not have suffered their injury. It provides us with ‘an exclusionary rule designed to identify events that will be treated as not having causal significance’,1 and in straightforward cases it does not cause any problems. Yet, it can lead to counterintuitive results in more difficult cases and so the courts have created convoluted exceptions that are hard to understand. The result is that this aspect of the law appears to be in a state of disarray. Turton advances an alternative approach to determining causation in negligence. She begins by outlining the theoretical framework that underpins her preferred model: corrective justice. This is a principle of interpersonal moral responsibility and is concerned with what is fair between the two parties in tort litigation, the claimant and defendant. There is injustice ‘when one person causes wrongful loss to another’ (p 9) and corrective justice requires the wrongdoer to repair the loss, usually by paying compensation to the victim. What is a wrongful loss? Apparently, this can be derived from the idea of ‘Kantian Right’ and the Golden Rule (that one should do unto others as you would have them do to you). Causation is ‘a central feature of corrective-justice based interpersonal responsibility’ since it is the causal relationship that ‘connects the claimant and defendant as parties to an interaction’ (p 20). This theory is often contrasted with distributive justice, which considers what is fair or just across society as a whole, rather than concerning itself with justice between the claimant and defendant. As such, if one accepts corrective justice as a compelling theory of tort liability, questions of policy or social welfare are irrelevant to determining such cases. Turton’s reasons for preferring corrective justice over alternative concepts of tort law is that it maintains coherence and she believes that this ought to be prioritised over other considerations (p 7). This has important implications for her approach to causation but even if, as I am, you are unconvinced by this framework, it should not put you off reading the rest of the book. Turton’s observations on causation are rewarding, regardless of one’s approach to tort theory. In Chapter 2, Turton contends that the best account of causation is Richard Wright’s NESS test (a Necessary Element in a Sufficient Set).2 This test states that: ‘a particular condition was a cause of (condition contributing to) a specific consequence if and only if it was a necessary element of a set of antecedent actual conditions that was sufficient for the occurrence of the consequence’.3 While the but for test has the attraction of apparent simplicity, ‘it only functions correctly in straightforward cases, and in those cases the NESS test operates just as simply’ (p 42–43). In contrast, the NESS test is able to cope with these more challenging cases without resorting to exceptional tests ‘whose scope and meaning are unclear’ (p 43). To take an example from the medical negligence context, in Barnett v Chelsea and Kensington Hospital Management Committee4 the defendant doctor had instructed the claimant night watchman who presented at casualty feeling sick, to go home and see his GP the next day. It turned out that the claimant’s symptoms were a result of arsenic poisoning and so he died. However, it was found that the claimant would have died anyway even if he had been admitted to the wards and treated with due care. It could not be shown that the defendant’s breach was the but for cause of the injury and so the claim failed. The NESS test is equally capable of dealing with simple cases like Barnett where there is only one set of conditions sufficient to cause the damage. In those scenarios, the NESS test collapses into the but for test. As Turton acknowledges, ‘the but for test is short for the NESS test where there is only one set of conditions’ (p 45). The NESS test comes into its own in more complex cases, such as where there are over-determined causes. Take the example of the Desert Traveller: A puts poison in the water keg of a desert traveller which is sufficient to kill her if she drinks it but before she drinks the water, B empties the keg, and the traveller dies of thirst. The but for test would produce the ‘absurd result’5 that nobody caused the traveller’s injury—but for A’s actions the traveller would still have died, and but for B’s actions the traveller would still have died. Neither of them caused her death. The NESS test, however, can deal with such problems: A’s act was prevented from becoming part of an actually occurring set of conditions that were together sufficient to cause the death, so A is not a cause of the harm. A set of conditions jointly sufficient to cause the death now exists containing just B’s act of emptying the flask. This set of conditions runs its course so it is an actually occurring set, so B is a cause (p. 48, emphasis in original). Space constraints prevent a detailed discussion of all the applications of this theory here, but of particular interest to me is Chapter 4, where Turton considers loss of a chance.6 The House of Lords has twice considered such claims. In Hotson v East Berkshire AHA,7 the claimant developed avascular necrosis after falling from a tree. There was a 75% chance that he would have suffered this injury anyway due to the fall and only a 25% chance that the defendant had caused this injury by carelessly failing to diagnose him. In Gregg v Scott,8 the claimant had non-Hodgkin’s lymphoma and alleged that the defendant’s delay in diagnosis had reduced his chances of surviving for 10 years from 42% (if he had been treated properly) to 25%. In neither of these cases could the claimants show on the balance of probabilities that but for the defendant’s negligence they would have avoided the damage. Instead, they reframed their cases as ones for a loss of a chance of a better outcome. Turton maintains that the House of Lords was correct to reject these claims. She states that ‘[a]lthough the loss of chance argument ostensibly reformulates the damage as the chance of avoiding physical harm … what it in fact achieves is to “discount” liability to reflect the degree of doubt over the fact of causation’ (pp 122–23). These loss of a chance arguments are ‘attempts to sidestep the difficulties of proof of causation of the physical harm on the balance of probabilities standard of proof’ (p 122). Instead, Turton advocates ‘recognition of a different conception of loss of a chance in the form of the opportunity to access treatment before the patient’s prospects of recovery declined’ (p 123). This opportunity ‘reflects an aspect of the patient’s autonomy interest and is lost when there is a worsening in the patient’s statistical chance of cure by the time she is properly diagnosed and given the opportunity for treatment’ (p 123). Since the damage is to the patient’s autonomy interest rather than his or her physical welfare, this damage ‘would be actionable whether or not the patient also suffers the eventual physical harm she sought to avoid’ (p 123) and valued independently. I have argued elsewhere that allowing negligence claims for lost autonomy would be hard to reconcile with established doctrine.9 But it is far from obvious that recognising this new form of damage is even consistent with the principles of corrective justice that Turton adopts. Under this theory, a loss is only wrongful if it interferes with an individual’s rights. Taking the mainstream definition of autonomy as the interference with a person’s desires or choices,10 one cannot have a ‘right’ to autonomy. I do not have a moral ‘right’ not to have my choices interfered with for the simple reason that giving me such a right would interfere with the same right of others.11 Negligence cases involve ‘making the choice of either preserving the ability of the defendant to act without legal hindrance or awarding damages to the injured claimant so as to restore (so far as possible) his or her ability to enjoy an autonomous existence’.12 As Christian Witting states, ‘[a]utonomy is a policy-based reason that can swing both ways.’13 It cannot, therefore, be justified under the Golden Rule. Given the mess that occurs when negligence extends its protection to intangible interests, it might be wiser not to recognise this nebulous interest, particularly if one wishes to prioritise coherence in the law. The remainder of the book addresses problems associated with the ‘evidentiary gap’.14 The most notorious of these cases is Fairchild v Glenhaven Funeral Services,15 where a negligent action was brought by the widow of a man who died of mesothelioma after being exposed to asbestos by a number of different employers during his working life. At the time, the mechanism initiating the genetic process which culminated in mesothelioma was unknown. It was accepted in the case that the trigger may have been a single asbestos fibre and that the condition was not aggravated by further exposure. Lord Rodger summarised the problem with this case: Because of the current state of medical knowledge about the aetiology of mesothelioma, it was impossible for the claimants to prove on the balance of probabilities that the men's illness had been triggered by a fibre or fibres inhaled while working with any particular employer and, more especially, while working with the particular defendants whom they had sued.16 In response, the House of Lords created or, more accurately given their earlier decision in McGhee v National Coal Board,17revived18 an exception to normal principles in cases of scientific uncertainty. A defendant who has materially increased the risk that a claimant would suffer from injury will be held to have caused that injury. It is undoubtedly true that the but for test cannot cope with the evidentiary gap. However, the NESS test does not fare much better for those who intuitively believe that the claimants in Fairchild should have succeeded. In this type of case, unlike the cases where claimants struggle to demonstrate that the defendant’s breach was a necessary element of a sufficient set, ‘the claimant faces the prior problem that the state of scientific uncertainty prevents the definition of a sufficient set of conditions from the harm that she has incurred’ (p 164). Cases such as Fairchild hold a defendant liable where they may not have been the cause of the claimant’s loss. If one accepts corrective justice, then ‘these claims ought to fail for want of proof of causation’ (p 165). While I can see the logic in this, I doubt I am alone in finding a theory unattractive if it cannot compensate dying workers whose employers have exposed them to known carcinogens just because other employers acted equally as reprehensibly. Despite my disagreements with some of Turton’s conclusions, I cannot recommend this outstanding book highly enough. Evidential Uncertainty in Causation in Negligence is a tremendous piece of scholarship that is lucidly written, thoroughly researched, and packed with stimulating insights. It can hold its own against the other excellent monographs that have recently been published on this topic,19 and clarifies many issues in this notoriously recalcitrant area of tort doctrine. Footnotes 1 M Jones, ‘Proving Causation: Beyond the “But For” Test’ (2006) 22 PN 251, 251. 2 ‘Identifying the Proper Function of Causation’. 3 R Wright, ‘Causation in Tort Law’ (1985) 73 Cal L Rev 1735, 1790. 4 [1969] 1 QB 428. 5 A Beever, ‘Cause-in-Fact: Two Steps Out of the Mire’ (2001) 51 U Toronto LJ 327, 331. 6 ‘Loss of a Chance’. 7 [1987] AC 750. 8 [2005] 2 AC 176. 9 C Purshouse, ‘Liability for Lost Autonomy in Negligence: Undermining the Coherence of Tort Law?’ (2015) 22 Torts LJ 226. 10 C Purshouse, ‘How Should Autonomy be Defined in Medical Negligence Cases?’ (2010) 15 Clin Ethics 107. 11 See R Dworkin in Taking Rights Seriously (Duckworth, 1977) 266–71. 12 C Witting, ‘The House that Dr Beever Built: Corrective Justice, Principle and the Law of Negligence’ (2008) 71 MLR 621, 634. 13 ibid. 14 ‘The Evidentiary Gap’, ch 5. 15 [2002] 3 WLR 89. 16 ibid, [124]. 17 [1973] 1 WLR 1. 18 In Fairchild Lord Bingham stated that Lord Bridge’s view in Wilsher v Essex AHA [1988] AC 1074 at 1090 that McGhee ‘laid down no new principle of law whatever’, should ‘no longer be treated as authoritative’ [22]. 19 See, eg S Green, Causation in Negligence (Hart 2015) and S Steel, Proof of Causation in Tort Law (CUP 2015). © The Author 2017. 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TI - Gemma Turton, Evidential Uncertainty in Causation in Negligence
JF - Medical Law Review
DO - 10.1093/medlaw/fwx006
DA - 2017-07-01
UR - https://www.deepdyve.com/lp/oxford-university-press/gemma-turton-evidential-uncertainty-in-causation-in-negligence-SM8gopzH2A
SP - 511
EP - 515
VL - 25
IS - 3
DP - DeepDyve
ER -