Australia: What's the Harm in Loss of a Chance? High Court rejects Loss of a Chance Claims

Tabet v Gett
Last Updated: 4 May 2010
Article by Olivia Dinkha

Judgment date: 21 April 2010

Tabet v Gett [2010] HCA 12

High Court of Australia1

In Brief

In a decision which will have far-reaching ramifications on plaintiffs, the High Court has held that the common law of Australia does not recognise claims for loss of a chance of a better medical outcome.


On 28 December 1990 the plaintiff, then six years old, came under the care of paediatric specialist, Dr Mansour, at the Royal Alexandra Hospital for Children. She had a history of persistent headaches and vomiting for ten days. It was assumed that the plaintiff had a streptococcal infection and accordingly she was prescribed penicillin and discharged that day.

On 29 December 1990 the plaintiff was readmitted to the hospital and remained under the care of Dr Mansour until she was discharged on 31 December 1990. Between her discharge and 11 January 1991 the plaintiff remained at home suffering from chickenpox. Her headaches and vomiting persisted and on 11 January 1991 she was referred to Dr Gett who was caring for Dr Mansour's patients while Dr Mansour was away. The plaintiff was readmitted to hospital on that date and was provisionally diagnosed as having post-chickenpox meningitis.

On 13 January 1991 the plaintiff suffered a neurological episode. The following day she suffered a serious deterioration in her condition and had a seizure. A CT scan was performed which revealed the presence of a medulloblastoma, a type of brain tumour.

On 16 January 1991 the plaintiff underwent surgery to remove the tumour. Removal of the tumour was only partially successful. She underwent chemotherapy and radiotherapy treatment. Although the plaintiff survived she was left with severe brain damage.

Supreme Court of NSW decision

The plaintiff brought proceedings against Dr Mansour and Dr Gett.

The plaintiff pleaded the defendant breached his duty to her and that this breach caused or contributed to her injury, loss and damage. In the alternative, the plaintiff pleaded that the defendant's breach led to "the loss of an opportunity to avoid injury, loss and damage".

The trial judge found that Dr Mansour was not negligent in his treatment of the plaintiff in failing to order a CT scan in December of 1990. There was no appeal of this decision.

However, the trial judge held that Dr Gett was negligent in failing to order a CT scan on 13 January 1991 and that as a result the plaintiff lost the chance of a better medical outcome because if a CT scan was ordered on that day, the plaintiff's tumour would have been detected that day and treatment to reduce intracranial pressure would have commenced immediately, either by the prescription of steroids or, less likely, the insertion of a drain.

In this way Studdert J found that the plaintiff lost the chance of a better medical outcome and in doing so his Honour considered himself bound by the decision in Rufo v Hosking2.

His Honour assessed the plaintiff's damages referable to her entire brain damage in the sum of $6,092,586. His Honour found that it was probable that the plaintiff's decline on 14 January 1991 contributed 25% to her ultimate disabilities, representing an assessment of $1,523,146. His Honour assessed the loss of a chance of a better medical outcome, that is avoiding the damage referrable to the deterioration on 14 January 2010, at 40%. Thus the plaintiff was entitled to 40% of $1,523,146, representing an award of damages in the sum of $610,000 against Dr Gett.

NSW Court of Appeal decision

The defendant appealed, challenging the trial judge's finding that he was negligent in failing to order a CT scan by 13 January 1991. The plaintiff cross-appealed, challenging the finding that the defendant's diagnosis of post-chickenpox meningitis made on 11 January 1991 demonstrated reasonable care on his part at that time. The plaintiff also challenged the trial judge's conclusion that she suffered no more than the loss of a chance of a better outcome and submitted that his Honour should have found on the balance of probabilities that the defendant's negligence caused the whole of the brain injury referrable to the seizure and deterioration on 14 January 1991. All these grounds of appeal failed.

The defendant further challenged the trial judge's findings that the plaintiff was entitled to compensation for the loss of a chance of a better outcome. The defendant was granted leave to reargue the correctness of the line of authority contained in cases such as Rufo and State of New South Wales v Burton3.

Assuming Rufo to be correct and applicable, the Defendant also challenged the trial judge's approach to the calculation of the lost chance. It was held that his Honour misapplied the loss of a chance analysis in coming to 40%. It was held that the relevant lost chance, if a valid approach, was no more than 15%.

In Rufo the question of whether damages for loss of a chance were available was not in issue as the parties had agreed at trial and on appeal that such damages were recoverable. The issue before the Court in Rufo was whether a case for damages for loss of a chance had been made out.

The Court considered that the approach adopted in Rufo and Gavalas v Singh4 involved a departure from conventional principles without clear support from the High Court where there were no compelling reasons to adopt such an approach and without consideration of the difficulties and complexities of the application of the doctrine. It was therefore held that the approach in these cases was "plainly wrong".

In not following Rufo and Gavalas the Court held that the doctrine of loss of a chance in medical negligence cases formed part of no recognised stream of authority and that it was not consistent with or permitted by Sellars v Adelaide Petroleum NL5 which recognised the loss of a chance of commercial value as an actual quantifiable loss. The Court held "the reiteration in Sellars of the statements of general principle as to proof of causation were contradictory to any permission to extend loss of a chance outside the realm of loss of a commercial opportunity".

The Court of Appeal further held that:

"It is for the High Court, and only the High Court, to reformulate the law of torts to permit recovery for physical injury not shown to be caused or contributed to by a negligent party, but which negligence has deprived the victim of the possibility (but not the probability) of a better outcome."

The Court also held that no clear limitations have been formulated for the application of the doctrine in relation to whether or not it only applies to medical negligence claims or to personal injury at large. In this regard the Court noted that allowing recovery for the loss of a better outcome "would not readily be limited to medical negligence cases, but would potentially revolutionise the law of recovery for personal injury".

Although it was not raised on appeal, the Court noted that the Civil Liability Act includes a codified definition of injury which does not include a risk of physical or mental injury. It was also noted that recognition of damages for loss of a chance of a better outcome, if involving a reformulation of the concept of causation, could not be reconciled with the principles relating to causation set out in ss 5D and 5E of the Civil Liability Act, the later which requires the plaintiff to prove "on the balance of probabilities, any fact relevant to the issue of causation".

The Court further held that there is no evidence that insurance companies or members of the public have adapted their personal or commercial relations in reliance upon authorities like Gavalas and Rufo.

High Court of Australia decision

The plaintiff was granted special leave to appeal to the High Court. The issues for determination were:

  1. Whether the Court of Appeal erred in holding that negligence should be assessed on the balance of probabilities alone and not on the basis of loss of a chance of a better outcome.
  2. Whether in any event the evidence established that the plaintiff lost an opportunity.
Gummow ACJ

Distinguishing between possibilities and probabilities, Gummow ACJ held that the Court of Appeal properly decided that it could not reformulate the law of torts to allow a plaintiff to recover for physical injury which was not caused or contributed to by a negligent party but where the negligence deprived the plaintiff of the possibility, as distinct from the probability, of a better outcome.

However, his Honour went on to state that:

"...this outcome will not require acceptance in absolute terms of a general proposition that destruction of the chance of obtaining a benefit or avoiding a harm can never be regarded as supplying that damage which is the gist of an action in negligence."

His Honour noted that had the plaintiff been able to establish a greater than 50% likelihood of a better outcome then she would have been able to establish causation on the balance of probabilities and thus would have succeeded in establishing the main branch of her claim in negligence.

Kiefel J

Her Honour affirmed that damage is the gist of a cause of action in negligence. Whilst the plaintiff suffered severe damage she was unable to prove that it was probable that had the treatment of corticosteroids been administered earlier the brain damage which occurred on 14 January 1991 would have been avoided.

Her Honour held that:

"Such a claim could only succeed if the standard of proof were lowered, which would require a fundamental change to the law of negligence. The appellant suffered dreadful injury, but the circumstances of this case do not provide a strong ground for considering such change. It would involve holding the respondent liable for damage which he almost certainly did not cause."
Hayne and Bell JJ

Hayne and Bell JJ agreed with the reasons of Kiefel J but added that:

"It need only be observed that the language of loss of chance should not be permitted to obscure the need to identify whether a plaintiff has proved that the defendant's negligence was more probably than not a cause of damage (in the sense of detrimental difference). The language of possibilities (language that underlies the notion of loss of chance) should not be permitted to obscure the need to consider whether the possible adverse outcome has in fact come home, or will more probably than not do so."
Heydon J

Heydon J rejected the plaintiff's appeal on the basis that there was no evidence that the plaintiff did lose a less than even chance of avoiding an adverse medical outcome as a result of the defendant's negligence. Given this finding, his Honour refused to answer the question of law raised by the parties on the basis that it had become a hypothetical issue and was therefore "purely abstract and academic".

Crennan J

Crennan J agreed with the reasons of Kiefel J that Australian law does not and should not permit the recovery of damages for the loss of a chance of a better medical outcome because such recognition would represent a major development in the common law. Her Honour held that such a shift in the common law should be left to the legislature:

"From the present vantage point, the alteration to the common law urged by the appellant is radical, and not incremental, and is therefore the kind of change to the common law which is, generally speaking, the business of Parliament."

Her Honour held that policy considerations against displacing the requirement of proof of causation in medical negligence cases included the fact that it would encourage defensive medicine which is the practice of safeguarding against possible malpractice claims as opposed to ensuring the health of a patient and the impact of this on the Medicare system and private medical insurance schemes as well as the impact on professional liability insurance of medical practitioners.


The High Court has rejected the availability of claims for the loss of a chance of a better medical outcome. This will have the effect of reducing the number of medical negligence claims because a plaintiff bringing such a claim will have to prove on the balance of probabilities that the injury suffered was caused by a breach of duty on the part of the defendant and not the possibility that a defendant's breach deprived the plaintiff of a better outcome.

The onus on a plaintiff to establish that a defendant's breach was causative of the injuries suffered on the balance of probabilities is codified in s 5E of the Civil Liability Act.

This decision represents a victory for defendants as the High Court refused to weaken the "requirement for proving causation such that...the plaintiff should have the benefit and the defendant the detriment of an easier proof of actionable damage for a negligence action".

Defendants and their insurers who did not reassess claims for loss of a chance of a better medical outcome following the Court of Appeal decision in Gett v Tabet6 should do so to take into account that the recovery of damages in such claims is now but a thing of the past.

1 Gummow ACJ, Haybe, Heydon, Crennan, Kiefel and Bell JJ
2 (2004) 61 NSWLR 678
3 [2006] NSWCA 12
4 (2001) 3 VR 404
5 (1994) HCA 4
6 (2009) 254 ALR

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

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