Whilst patients depend on medical practitioners for an accurate diagnosis and effective treatment, errors such as misinterpretation of test results, miscommunication of symptoms, or inadequate follow-up can lead to delayed, missed or incorrect diagnoses. Although these errors range in severity, and may not always be detrimental to the patient’s care, medical professionals are under increasing pressure to ensure that the care they provide meets accepted clinical standards.
This article examines the elements that need to be established to prove that a diagnostic error constitutes medical negligence, defences that medical practitioners can rely on and case examples in Australia.
The criteria of proving medical negligence, by way of diagnostic error is as follows:
A medical practitioner can prove that their actions were not negligent if their actions or omissions were consistent with a practice that is widely accepted by peer professional opinion to be competent professional practice: Section 5PB of Civil Liability Act 2002 (WA) (‘CLA’).
The practice does not have to be universally accepted, but does need to be widely accepted. For example, if a GP fails to order an MRI for persistent headaches, but expert evidence shows that most GPs wouldn’t order a scan in those circumstances, then breach will not be established.
Consideration is given to factors such as whether the medical professional has appropriately documented a detailed history of the patient’s symptoms, arranged necessary referrals for further tests and investigations, and recognised the urgency required in treating certain medical conditions. A patient can also be overly serviced, such as undergoing unnecessary tests that do not relate to their present symptoms, which may result in a differential misdiagnosis.
The correctness and reasonableness of the medical practitioner’s decision and diagnosis is also to be assessed based on the information available at the time the decision or diagnosis was made.
Even where a claimant can prove negligence, their claim may fail because of causation. By reference to section 5C of the CLA, the claimant must show that the ‘diagnostic error’ was a necessary condition of the occurrence of the harm, and it is appropriate for the scope of the medical practitioner’s liability to extend to the harm so caused. Proving the error is not enough.
Proving that the error caused harm can be difficult. There may be conflicting or insufficient evidence of whether an event would or would not have occurred. The issue is further complicated when multiple medical practitioners are involved, and there are multiple events or omissions that may have contributed to a diagnostic error. Courts rely on expert opinion to draw inferences regarding the probable link between the diagnostic error and the harm rather than mere possibilities.
In circumstances where it is alleged there was a delayed diagnosis, courts would look at whether an earlier diagnosis would have led to a materially better outcome, such as higher survival rates, less invasive treatment or a reduced disability. The case of Austen v Tran [2022] ACTSC 114 is an example where the plaintiff alleged that the defendant failed to take steps to diagnose terminal non-Hodgkin’s lymphoma at an earlier stage. The court considered that the initial presentation of leg pain, weakness and other symptoms were rare in with this condition, and that it would not have been reasonable for a general practitioner to consider that as a differential diagnosis. In any event, an earlier diagnosis would only have improved the chance of an extended remission period, rather than completely avoiding the disease.
A similar causation issue was raised in Alrifai v Australian Capital Territory [2022] ACTSC 48 regarding the failure to consider an earlier diagnosis of pancreatic cancer based on CT scans. The court accepted the evidence of two experts who said that even if the tumour had been diagnosed earlier, the earlier diagnosis would not have altered the terminal diagnosis or the need for adjuvant chemotherapy.
Causation was established in a WA decision of East Metropolitan Health Service & South Metropolitan Health Service v Martin [2017] WASCA 7. The claimant was treated for suspected arthritis in his lower spine. Multiple failed attempts were made to insert a catheter line with one attempt causing significant pain in his right arm. The claimant reported ongoing arm pain, numbness, tingling and grip difficulty, and was later confirmed to have right median nerve palsy, and a haematoma compressing the nerves and blood vessels. Breach was made out because the doctors should have ordered an ultrasound within 10 days of the failed catheter line, which would have diagnosed the haematoma and he could have undergone treatment. The Court of Appeal held that causation was made out as the delay in diagnosing and treating the haematoma caused the claimant to develop the nerve palsy.
Delays are not excusable where symptoms clearly warranted a timely investigation, regardless of service standards and hospital constraints.
This article was written by Sara Stamenkovic, Lawyer Insurance & Risk