Good health cannot be taken for granted.
There are a number of different types of health insurance policies available. The most cost effective cover is one that reimburses 100% of the cost (less a voluntary excess) of any hospital treatment.
Some policies, including some brands which are household names only cover surgical admission to hospital which means if you need chemo therapy for example, you have no cover.
Some policies will also cover the cost of drugs which are not funded by Pharmac, though most do not. This means that if a new drug is available, which costs thousands of dollars for a course, and is not subsidised by Pharmac, you aren’t covered, even if your life depends on it.