Loss of chance
Dimitra Dubrow, Principal
Last year, the High Court delivered a very important decision
about the 'balance of probabilities' standard, which was tested in
the case of Tabet v Gett.
Tabet v
Gett
Tabet was a case about the delayed diagnosis of a brain tumour
in a young girl and the effect of that delay on her severe brain
damage. The judge hearing the case decided that there was a 40 per
cent (less than even) chance that the girl would have avoided 25
per cent of the brain damage had the tumour been diagnosed in an
appropriate timeframe, which was about 24 hours before the actual
diagnosis was made. Over that 24 hour period, the girl's condition
worsened, her raised intracranial pressure was not treated and she
suffered a seizure.
The case was appealed all the way to the High Court. The court
did not agree with the judge and confirmed the 'balance of
probabilities' test of causation, that is, the need to show that
the negligence more likely than not caused the injury or medical
condition. The court said it was not enough to show that there was
a chance - such as a 40 per cent chance - that the outcome would
have been better. Rather, it had to be shown that diagnosis of the
brain tumour a day earlier would have more likely than not avoided
25 per cent of the brain damage. The court was not prepared to
change the law and 'lower' the test for causation.
Implications of High
Court decision
The decision has a number of implications for medical law
claims, especially ones involving progressive illnesses, for
example, where a doctor unreasonably fails to act on a patient's
symptoms which leads to a delayed diagnosis of cancer. In those
cases, it can sometimes be hard to work out what part of the
condition would have been avoided with timely treatment. Because of
the court's decision, it is important that medical evidence focus
on the likely or probable difference and not on possibilities or
lost chances.