Wallace v Kam [2013] HCA 19

While I was in the middle of studying for my most recent post-grad course on medical law, the High Court of Australia published its ruling in the case of Wallace v Kam. While only a short judgement, it has set down the law with respect to a medical practitioner's duty to warn of material risks to their patients, in light of the provisions of the Civil Liability Act 2002 (NSW).

Case Note: Wallace v Kam [2013] HCA 19

The recent decision by the High Court of Australia in Wallace v Kam [2013] HCA 19 clarifies the position of medical practitioners in failing to disclose material risks to patients, in situations where an injury unrelated to an undisclosed risk materialises.

Background

Mr Wallace was treated for a condition of his lumbar spine by Dr Kam, a neurosurgeon, who failed to warm him of two inherent risks in a surgical procedure. One was temporary damage to nerves in his thighs, known as ‘bilateral femoral neurapraxia. The second was a 5% chance of “permanent and catastrophic paralysis resulting from damage to his spinal nerves (at [1]). The surgery was unsuccessful, and in addition, Mr Wallace unfortunately sustained neurapraxia. He did, however, avoid the risk of paralysis.

Mr Wallace claimed damages for the neurapraxia, alleging Dr Kam negligently failed to warn him of either risk, and that had he been so warned of either or both, he would not have undergone the surgery.

Harrison J dismissed the claim, finding that even if Mr Wallace had been warned of the risk of neurapraxia, he would have gone ahead with the surgery regardless. His Honour declined to make any finding regarding the risk of paralysis on the grounds that “legal cause” of Mr Wallace’s neurapraxia, “could never be the failure to warn of some other risk that did not materialise” (Wallace v Ramsay Health Care Ltd [2010] NSWSC 518 at [96]).

Mr Wallace appealed to the NSW Court of Appeal where Allsop P and Basten JJA dismissed the appeal on basis that a doctor should not be held liable for a harm that did not directly arise from the alleged breach of duty (Wallace v Kam [2012] NSWCA 82 at [18] (per Allsop P) and [173] (per Basten JA)). Beazley JA dissented on the basis that the risk of paralysis was one that Mr Wallace would not have borne had he been properly informed. The risk was not of the kind mooted by Gummow J in Chappel v Hart [1998] HCA 55 at [66], where his Honour considered the hypothetical situation of Mrs Hart suffering injury through the misapplication of anaesthetic; a risk completely unrelated to Dr Chappel’s duty to inform her of material risks. The risk of neurapraxia and the risk of paralysis were both material risks Dr Kam had a duty to warn Mr Wallace about. In the hypothetical of Gummow J, the harm and the duty owed are unrelated; in the case of Mr Wallace though, the Dr Kam breached his duty to inform, and as a direct result Mr Wallace suffered harm.

The High Court Decision

The High Court (French CJ, Crennan, Kiefel, Gageler and Keane JJ) unanimously upheld the decision of the NSW Court of Appeal, dismissing Mr Wallace’s appeal.

The court restated the common law duty of medical practitioners established in Rogers v Whitaker (1992) 175 CLR 479 as being to “warn the patient of “material risks” of physical injury inherent in a proposed treatment” (at [8]). However, the court held that the damage suffered by the patient was not an impairment of their “right to choose”, nor exposure to an “undisclosed risk” (at [9]). Rather, the damage is, limited to the physical harm sustained by the patient in undergoing the procedure (at [9]). In other words, the patient must sustain physical injury in order for the failure to warn to be actionable. The question therefore, is whether the harm sustained must be the one the medical practitioner failed to warn of. Such a question leads to considerations of causation where the harm sustained is not a material risk that was not disclosed.

The court considered that the issue of causation involved two questions: how the particular harm occurred; and a “normative question as to whether legal responsibility for that particular harm occurring in that way should be attributed to a particular person.” (at [11]). While under the common law, these two questions had often been subsumed under the language of “directness” and “proximity”, the statutory requirements under the Civil Liability Act 2002 (NSW), s 5D, made these two questions distinct, being ss 5D(1)(a) and 5D(1)(b) respectively. The answer to the first question is an entirely factual one: was negligence a necessary condition of the harm suffered? (at [14]). In the case of a medical practitioner failing to exercise reasonable care and skill in warning a patient of material risks, the factual question is to be determined by s 5D(3), “If it is relevant to the determination of factual causation to determine what the person who suffered harm would have done if the negligent person had not been negligent: (a) the matter is to be determined subjectively in the light of all relevant circumstances”. The second, normative, question is whether it is appropriate for the scope of the negligent person’s liability to extend to the harm (at [14]). This is to be answered in accordance with s 5D(4) that states, “For the purpose of determining the scope of liability, the court is to consider (amongst other relevant things) whether or not and why responsibility for the harm should be imposed on the negligent party.”

In assessing the statutory tests, the court concluded that in reality they simply restated the common law. Therefore, the factual test under s 5D(1)(a) is “nothing more or less” than the “but for” test: on the balance of probabilities, would the harm that occurred not have occurred but for the negligence alleged? (at [16]). Under the s 5D(1)(b) test, the court considered that the cases will fall into one of two categories: an established class; and novel cases. Those falling into the established class will be answered by the application of precedent; “appropriate” is determined by reference to the limits of the duty to inform at common law. The novel class is answered through the application of s 5D(4): “What is required in such a case is the identification and articulation of an evaluative judgment by reference to “the purposes and policy of the relevant part of the law”” (at [23]).

In the case of a failure to warn of a material risk that does not materialise, but nonetheless a patient suffers an injury as a result of agreeing to the procedure, the court held that there was a limiting principle, being, “the scope of liability in negligence normally does not extend beyond liability for the occurrence of such harm the risk of which it was the duty of the negligent party to exercise reasonable care and skill to avoid.” (at [24]). The court cited with approval the decision of the House of Lords in Banque Bruxelles Lambert SA v Eagle Star Insurance Co Ltd [1997] AC 191, where, at 213, it held that a person is only responsible for the consequences of the information they provided being wrong; not all the consequences of a particular course of action a person may embark upon as a result of that information. The rationale given for this principle was that the elements of duty and causation of damage in negligence serve different functions. The duty of care imposes a “forward-looking rule of conduct” while causation imposes “a backward-looking attribution of responsibility for breach of the rule” (at [26]).

The court drew a distinction though, between cases where an injury occurring is the accumulated risk of several factors, and separate and distinct possible harms (at [34] and [36]). In the former, a failure to warn of one of the risk factors, which if known would lead to the patient not consenting to a procedure, will render the medical practitioner liable. In the latter case however, the potential harms are unrelated. Thus the injury is not the consequence of the lack of information they failed to provide regarding a distinct harm. Such was the finding of the court with regard to Mr Wallace; the risk of paralysis was not a contributing factor to the risk of neurapraxia, and as Mr Wallace was found to be willing to proceed with the procedure if he had known of the risk of neurapraxia, his appeal was ultimately unsuccessful.

Analysis and Conclusions

While the High Court in Wallace v Kam [2013] HCA 19 has reaffirmed the widely held understanding of the law regarding material risks, the reliance on precedent under the ss 5D(1)(a) and 5D(1)(b) tests does not solve the issue illustrated starkly by the differences between its judgment and those of Allsop P and Basten JA of the NSW Court of Appeal on the one hand, and Beazley JA on the other. Indeed, the issue is discussed in the judgment at [26], where their Honours note that while the “consequences of negligence is often coextensive with the content of the duty of the negligent party” it “is not always so coextensive.” The problem arises insofar as the court accepted that because the duty of care is forward looking and causation of damage is backwards looking, the “policy considerations” informing each may be different. But, this begs the question as to how the duty of care is to be enforced if the only means by which it can be enforced is not considered to be coextensive? There is no doubt that Dr Kam failed to warn Mr Wallace of the risk of paralysis, but should Dr Kam therefore be able to breach this duty with impunity simply because it was another harm that eventuated? Such was inherent in the reasoning of Beazley JA (Wallace v Kam [2012] NSWCA 82 at [136]-[151]). In her Honour’s view, “the causation question has to be determined having regard to the content of the duty, namely a duty to warn of material risks.” (at [148]). That being said, the passages cited in support of this view (at [147]) from Rosenberg v Percival [2001] HCA 18 at [86] (per Gummow J) refers to “that risk” in regard to a risk not warned of eventuating, not to a different risk. The other passages her Honour cites from Chappel v Hart [1998] HCA 55 at [7] (per Gaudron J) and [65] (per Gummow J) simply state the content of the duty to warn, not how it relates to the coextensive duty of causation. While the foregoing may address precedential issues, does not address the logical ones that are at the core of Beazley JA’s judgment as to ability to enforce the duty, which remain unanswered. Nonetheless, we now have a clear ratio as to the state of the law with regard to a failure to warn of material risks that do not eventuate, but where injury occurs otherwise. While this may set at ease the minds of medical practitioners and lawyers, it will do little to assuage the worries of patients in future who may be in a similar position to Mr Wallace.