Accident Compensation successfully appealed a High Court test case requiring ACC to compensate all adverse medical outcomes. Accident compensation for ‘treatment injury’ requires an outcome outside the ordinary, occasioning a measure of surprise, the Court of Appeal ruled.
Since its 1970s introduction, ACC statutory insurance cover for accidents has struggled to accommodate compensation for medical misadventure. Clinicians can never predict surgical outcomes with certainty. What is a medical ‘accident’ has proved difficult to define. The Accident Compensation Act has been amended multiple times. Since 2005, patients claiming accident compensation for ‘treatment injury’ must prove their injury was ‘not a necessary part or ordinary consequence of treatment.’
Consumer advocates sued ACC in two test cases. In the first, a woman had suffered a stroke following emergency surgery to isolate an aneurysm in the brain. Specialist advice was that strokes were possible in 15-22 per cent of cases. The second suffered partial paralysis after surgery on her spine. This adverse consequence might occur in 10-38 per cent of cases, specialists said.
The High Court ruled any outcome with a statistical probability of less than fifty per cent was ‘not an ordinary consequence of treatment.’ For ACC, practical effect of this ruling was that all adverse surgical outcomes became eligible for accident compensation. The Court of Appeal was told it was very rare for surgeons to operate when there was a risk of adverse outcomes in excess of fifty per cent; such surgery would be attempted only when the patient’s life was otherwise at risk.
To be ‘not an ordinary consequence’ the outcome must be unexpected, the Court of Appeal ruled. Chemotherapy cancer treatments provide an example, it said. Many patients suffer severe side effects, but this is not a ‘surprise;’ it is an ordinary consequence of treatment.
Accident Compensation Corporation v. Ng – Court of Appeal (7.07.20)
20.118