Adelaide medical negligence lawyer Mal Byrne writes about the importance of showing “causation”, illustrated by an Australian cancer misdiagnosis case.
Proving medical malpractice in medical negligence claims is difficult and does not necessarily mean that you will get compensation. In virtually every case, you will need to find a suitably qualified expert in the relevant field of medicine who will say that the doctor or hospital concerned failed in their care of the patient. Even if you succeed in finding an expert to support your case, you can be confident that the defendant’s insurer will find an equally qualified expert with an opposing view.
However while proving malpractice is difficult, the majority of medical negligence claims that fail do so in circumstances where the patient was able to prove malpractice on behalf of the doctor or hospital, but was not able to prove that the bad medical outcome that s/he suffered would have been substantially different if the negligence had not occurred. This is particularly so in cases of delayed diagnosis of cancer. All doctors will tell you that early detection is the key to getting the best outcome for the cancer patient but where a doctor fails in his or her care to the patient by not following through on symptoms or scans that should have alerted him or her to the risk or presence of cancer, the patient will only get compensation if he or she can show that he would have been in a substantially better position in terms of treatment and the prognosis of the cancer if it had been detected earlier.
The case: Coote v Dr Kelly
The difficulty that patients face in these circumstances is illustrated by the Supreme Court of New South Wales decision of Coote and Dr Kelly handed down on 14 March 2012 (Coote v Dr Kelly  NSW SC 219). In that case, Mr Coote presented to Dr Kelly in September 2009 with a lesion on the side of his foot which Dr Kelly diagnosed as a plantar wart when the lesion turned out to be a virulent form of skin cancer called Acral Lentiginous Melanoma. Dr Kelly had continued to treat the lesion as a wart up to March 2011. The lesion was not correctly diagnosed until March 2011 and by that stage it had metastasised. Mr Coote was so ill that he was allowed to give his evidence on commission (on video) just in case he passed away before the matter went to trial.
The oncologists who gave evidence for each side agreed on the following:
– That the lesion diagnosed in March 2011 was a very advanced 4.4 millimetre melanoma;
– The melanoma had two different colours;
– A melanoma of that size with two positive lymph nodes had been around for a considerable time, at least a period of a year.
Noting that the lesion when diagnosed was 4.4 millimetre thick, the expert witnesses were asked to give an opinion as to the size of the tumour in 2009. Mr Coote’s lawyers argued that the tumour was less than 2 millimetres in September 2009 and that Mr Coote’s prognosis if the tumour had been diagnosed at that stage was that he had an 89% chance of surviving five years where as in April 2011, he had only 18.8% chance of surviving five years. That substantial difference in life expectancy would be enough to establish causation. However, the Court preferred the evidence of the defendant’s expert. When the doctors thought that the melanoma was a plantar wart, they repeatedly picked at it and pared it with a pumice stone. Hence, even though the tumour was 4.4 millimetres when cut out in March 2011, the Judge agreed with the defendant’s expert who thought that the tumour was probably thicker than 4.4 millimetres in reality due to the amount of work that had been done on it beforehand. Given that it was more than 4.4 millimetres when excised, His Honour preferred the evidence of the defendant’s expert that in September 2009, it probably had a thickness of 2.1 to 4 millimetres. That range of thickness meant that it was not a melanoma that could be surgically excised with complete cure. Even if it was excised, the defendant’s expert said that it probably had already metastasised in September 2009. Given that the Court therefore accepted that the tumour had metastasised in September 2009, the court held that any treatment for melanoma would have been the same no matter when it was diagnosed and that there would have been little or no difference in life expectancy. Metastasis was the key. Once the tumour had metastasised, the chance of cure was gone. As such, causation was not established and the claim failed. The Court referred to the High Court decision of (Tabet v Gett) which found that the loss of a chance of a better medical outcome was not compensable.
What it means for future delayed diagnosis/misdiagnosis cases:
To establish causation in a delayed diagnosis case, the person suing must show that she/he would have been in a substantially better position than what she/he is in now if the illness had been detected earlier. In cancer cases, this will probably mean that the cancer was at a different stage and that the treatment plan and life expectancy/prognosis would have been substantially different. Hence, if you are the victim of a delayed diagnosis of cancer on any serious progressive illness, you should seek legal advice not only on whether malpractice has occurred, but whether you can obtain the evidence needed to show causation i.e. that the delayed diagnosis has caused damage in that you would have been in a substantially better position if the delay had not occurred.
Author: Mal Byrne
Tindall Gask Bentley is South Australia’s largest personal injury law firm. To arrange a free initial appointment with Mal, contact TGB’s Adelaide or Salisbury offices, or register online here.