On 9 April 2009, the NSW Court of Appeal handed down its long-awaited judgment in Gett v Tabet. The case required the Court to rule on the vexed issue of loss of a chance - where a defendant's negligence lessens a plaintiff's chances of avoiding greater loss or damage, but falls short of being causative of such loss or damage under traditional principles of legal causation.

Recent years have seen an increased frequency of damages awards for loss of a chance, most commonly in medical negligence cases where misdiagnosis or, more frequently, delay in diagnosis deprives the patient of an opportunity to receive treatment which may have resulted in an improved outcome. Authorities supporting the proposition that damages can be awarded for loss of chance are Gavalas v Singh (2001) and Rufo v Hosking (2004), appellate decisions in medical negligence cases in Victoria and NSW respectively. The concept of damages for loss of a chance, however, is not limited to the sphere of medical negligence.

Reema Tabet, aged 6 at the time, was admitted to hospital on 11 January 1991 with symptoms including headaches and vomiting. She came under the care of Dr Gett, a paediatrician, who initially considered Tabet to be suffering symptoms of resolving chicken pox and possibly meningitis. On 13 January Tabet exhibited a number of abnormal neurological signs. On 14 January her neurological condition deteriorated further and she suffered from a seizure. A CT scan was performed and a brain tumour diagnosed. Tabet underwent surgery and other treatment but was left with significant brain damage.

At first instance, Studdert J found that Dr Gett had breached his duty of care by failing to order a CT scan on 13 January, but was not persuaded that the discovery of the tumour on 13 January would have led to Tabet being treated in such a way as would have avoided the brain damage which occurred on 14 January. Therefore, he was not satisfied that the damage had been caused by Dr Gett's negligence.

However, Studdert J did find that, had the tumour been detected by a CT scan on 13 January, treatment would have commenced prior to the deterioration on 14 January and Tabet would have had a chance of a better outcome. On this basis, he determined that Tabet was entitled to damages for loss of a chance.

In assessing damages, Studdert J found that the deterioration on 14 January contributed 25% to Tabet's ultimate disabilities, so multiplied the agreed quantum figure by 25% to give the proportion of damages referable to the deterioration. His Honour then awarded Tabet damages of 40% of this proportion, on the basis of a finding that arrangement of a CT scan on 13 January would have provided a 40% chance of a better outcome.

Dr Gett appealed to the Court of Appeal and Tabet filed a cross-appeal. The appeal covered several issues including the finding of breach against Dr Gett and whether legal causation had in fact been established. However, the issue of central importance and interest on the appeal and the issue upon which Studdert J's judgment was overturned was the validity of the awarding of damages for loss of a chance.

The Court of Appeal (comprising Allsop P, Beazley JA and Basten JA) determined that the decisions in Gavalas and Rufo were "plainly wrong" and that damages for loss of a chance could not be awarded. The Court of Appeal's findings included the following:

  • the concept of loss of a chance departs from conventional principles of tort law and forms no part of a recognised stream of authority
  • in neither Gavalas nor Rufo were the difficulties and complexities of the application of the concept of loss of a chance considered, and no clear limitations had been formulated for the application of the concept
  • the loss of a chance concept was inconsistent with definitions in tort reform legislation concerning the nature of harm required to justify a finding of negligence, and the appropriate test of causation to give rise to an obligation to pay damages
  • the setting of the law of torts on a new path of proof of causation based upon creation of risk and policy for fair recompense is a matter of policy for the High Court, rather than an intermediate appellate court.

The last of these findings would appear to be a thinly veiled call by the Court of Appeal for the High Court to consider the issue. Should Tabet make an application, special leave to appeal to the High Court would appear likely to be granted given the now inconsistent authorities of Gavalas, Rufo and Gett, and the importance of the issue, not only to medical negligence cases, but to the law of negligence in general.

Perhaps militating against Tabet making an application for special leave is the Court of Appeal's finding that, had loss of a chance been good law, Tabet's loss of a chance was of the order of 15% rather than the 40% found by Studdert J. This may cause Tabet's advisers to consider whether, leaving aside the wider implications, the amount in issue for Tabet makes a High Court appeal worthwhile pursuing.

Even if it is not pursued, a similar issue may soon be revisited by the NSW Court of Appeal in O'Gorman v Sydney South West Area Health Service. In that case, radiologists negligently failed to detect changes on a mammogram leading to a delay in diagnosis of a breast tumour from March 2006 to January 2007. Some time after January 2007, the tumour metastasised (spread). Despite accepting expert evidence that the risk of the tumour metastasising had increased by only 10% between March 2006 and January 2007, Hoeben J of the NSW Supreme Court found that full damages should be awarded on the basis that the tumour and metastasis should be regarded as separate and that the delay in diagnosis of the tumour should be viewed as an independent cause which materially contributed to the injury.

Whether Hoeben J's distinction of the facts in O'Gorman from other loss of chance cases is accepted as valid by appellate courts remains to be seen. In the meantime, the law on loss of a chance can still not be considered to be settled. The High Court's consideration of the issue, be it through Gett, O'Gorman, or another case, will be keenly awaited.

Gett v Tabet [2009] NSWCA 76

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