The High Court interpreted the meaning of “ordinary consequence” of treatment in ACC v Ng [2018] NZHC 207, an important determinant of cover for treatment injury.

The Accident Compensation Act provides cover for personal injuries caused by medical treatment, such as surgery, in certain circumstances. The treatment must be by a registered health professional. The personal injury must be caused by the treatment, and must not be a “necessary part, or ordinary consequence” of the treatment, taking into account all the circumstances of the treatment including the person’s underlying health condition. For example, a stroke may be a risk of surgery for a brain aneurysm, but if it occurs, was it an “ordinary consequence” of treatment?