Insights

In brief - A patient will not be compensated for physical harm for which he was prepared to take the risk

A medical practitioner will only be liable for a breach of the duty to warn a patient of all material risks if such a breach was the cause of the risk that in fact materialised.

Patient sues neurosurgeon following surgical procedure

The case Wallace v Kam [2013] HCA 19 arose out of a claim by a patient, Mr Ian Wallace, against his neurosurgeon, Dr Andrew Kam, regarding a surgical procedure performed on his lumbar spine.

The case considered the two limb test for causation under section 5D of the Civil Liability Act 2002 (NSW) (CLA), being factual causation and the scope of liability. The High Court of Australia held that Mr Wallace had established the first limb but not the second limb of causation under section 5D of the CLA.

Doctor's duty to warn patient of material risks of physical harm in proposed treatment

It has long been recognised by common law that a medical practitioner owes a patient a single comprehensive duty to exercise reasonable care and skill in the provision of professional advice and treatment (see Rogers v Whitaker [1992] HCA 58). A component of that single comprehensive duty is ordinarily to warn a patient of material risks of physical harm inherent in a proposed treatment.

In Wallace v Kam, Mr Wallace claimed that Dr Kam negligently failed to warn him of two inherent risks with the surgical procedure: neuropraxia (a type of nerve injury) and paralysis. In Mr Wallace's case, the risk of neuropraxia materialised but the risk of paralysis did not. Mr Wallace claimed damages from Dr Kam for the neuropraxia he sustained.

Factual causation and the scope of liability

The central issue in Wallace v Kam was causation, which is a two limb test under section 5D of the CLA, with the first limb being factual causation and the second limb being the scope of liability. Section 5D of the CLA provides that:

1) A determination that negligence caused particular harm comprises the following elements:

(a) that the negligence was a necessary condition of the occurrence of the harm ("factual causation"), and

(b) that it is appropriate for the scope of the negligent person’s liability to extend to the harm so caused ("scope of liability").

(2) In determining in an exceptional case, in accordance with established principles, whether negligence that cannot be established as a necessary condition of the occurrence of harm should be accepted as establishing factual causation, 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.

(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, subject to paragraph (b), and

(b) any statement made by the person after suffering the harm about what he or she would have done is inadmissible except to the extent (if any) that the statement is against his or her interest.

(4) 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.

Supreme Court of NSW finds no factual causation

At trial, the Supreme Court of NSW dismissed Mr Wallace's claim on the basis that he failed to establish factual causation (see Wallace v Ramsay Health Care Ltd [2010] NSWSC 518).

The Supreme Court held that while Dr Kam negligently failed to warn of the risk of neuropraxia, Mr Wallace would have chosen to undergo the surgical procedure even if warned of that risk (i.e. Mr Wallace accepted the risk of neuropraxia).

The court also held that the legal cause of the neuropraxia "could never be the failure to warn of some other risk that did not materialise [i.e. the risk of paralysis]". On this basis, the Supreme Court declined to make any finding about whether Dr Kam negligently failed to warn Mr Wallace of the risk of paralysis.

NSW Court of Appeal finds factual causation but no scope of liability

On appeal to the NSW Court of Appeal, Mr Wallace asserted that, even if he would have accepted the risk of neuropraxia had he been warned, he would not have proceeded with the surgery if he had been warned of the additional risk of paralysis. On this basis, Mr Wallace asserted that the Supreme Court erred in finding that the legal cause of the neuropraxia could not be the failure to warn of the risk of paralysis.

The Court of Appeal dismissed Mr Wallace's appeal. While the Court of Appeal found that Mr Wallace would not have proceeded with the surgery if he had been warned of the risk of paralysis, it was not appropriate to find Dr Kam liable for the neuropraxia on the basis that he failed to warn Mr Wallace of the risk of paralysis, as the risk of paralysis did not materialise. That is, the Court of Appeal found that Mr Wallace had established the first limb of causation (i.e. factual causation) but not the second limb of causation (i.e. scope of liability).

High Court of Australia upholds finding of the Court of Appeal

The High Court of Australia upheld the findings of the Court of Appeal.

In dismissing Mr Wallace's appeal, the High Court held that the determination of causation at common law involves two questions: a question of historical fact as to how 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].

According to the High Court, section 5D of the CLA requires those two questions to be kept distinct [at 12]. The High Court held that:

  • "the determination of factual causation in accordance with section 5D(1)(a) [of the CLA] involves nothing more or less than the application of a 'but for' test of causation" [at 16]; and that
  • the scope of liability in accordance with section 5D(1)(b) of the CLA requires a court to consider "whether or not, and if so why, responsibility for the harm should be imposed on the negligent party" [at 23]. In this regard, the High Court acknowledged that the underlying policy requiring a medical practitioner to exercise reasonable care and skill in providing warnings to a patient of material risks inherent in a proposed treatment is "to protect the patient from the occurrence of physical injury the risk of which is unacceptable to the patient" [at 36].

Patient would have undergone medical procedure even if warned of risk of neuropraxia

Applying the above principles, the High Court held the following:

  • Dr Kam breached his single comprehensive duty to exercise reasonable care and skill in the provision of professional advice and treatment to Mr Wallace by failing to warn Mr Wallace of the risk of neuropraxia and the risk of paralysis inherent in the surgical procedure.
  • Dr Kam's breach of duty was a necessary condition of the neuropraxia Mr Wallace sustained. Factual causation in accordance with section 5D(1)(a) of the CLA was satisfied because Mr Wallace would not have chosen to undergo the surgical procedure and would therefore not have sustained the neuropraxia if warned of all material risks.
  • However, it was not appropriate for the scope of Dr Kam's liability to extend to the neuropraxia sustained by Mr Wallace in circumstances where he would not have chosen to undergo the surgical procedure had he been properly warned of all material risks, but where he would have chosen to undergo the surgical procedure even if he had been warned of the risk that in fact materialised.

In this case, Mr Wallace was willing to accept the risk of neuropraxia and, as such, any failure by Dr Kam to warn him of the risk of paralysis could not be the legal cause of the neuropraxia that materialised. Accordingly, Mr Wallace was not be to compensated for the neuropraxia he sustained.

Court will consider factual causation and scope of liability in assessing causation

In summary, the court will consider the questions of factual causation and the scope of liability in assessing causation under section 5D of the CLA. The determination of factual causation involves nothing more or less than the application of the "but for" test of causation.

The scope of liability for breach of the duty to warn should reflect the policy to protect the patient from the occurrence of physical harm, the risk of which is unacceptable to the patient. A patient will not be compensated for the occurrence of physical harm for which he was prepared to take the risk.

 

This article has been published by Colin Biggers & Paisley for information and education purposes only and is a general summary of the topic(s) presented. This article is not specific legal advice. Please seek your own legal advice for any questions you may have. All information contained in this article is subject to change. Colin Biggers & Paisley cannot be held responsible for any liability whatsoever, or for any loss howsoever arising from any reliance upon the contents of this article.​

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