Written word helps guide decisions

New Zealanders can express a wish to stop life-sustaining treatments, although the ultimate legal test is what is in the person's best interests and that is a medical decision.

Auckland family law expert Stephen McCarthy says the best way for people to express their wishes is through what is called an enduring power of attorney. This is intended to benefit people who become unable to make or communicate decisions about their property or personal care and welfare, by getting someone they know and trust to act on their behalf. Any action taken by the person with power of attorney, in relation to the donor's personal care and welfare, must have the same effect as what the donor would do if they had the capacity to make the decision.

McCarthy says that in the case of turning off life support, if the attorney made that decision alone they could potentially be in the gun for aiding and abetting suicide.

In New Zealand there have been at least two cases where applications were made to the court for a life-sustaining treatment to be stopped. In each case the legal test applied was based on what was in the best interests of the patient.

"The express wish of the person does not override everything," McCarthy says. "You can't express that wish in advance and expect it to be honoured regardless of medical opinion or anything else. The legal test is what's in the person's best interests and that ultimately ends up being a medical question." McCarthy says that without a "best-interests test" that was ultimately based on medical evidence, "you would have euthanasia".

People should talk to their family about what they wanted in such circumstances, much as discussion about wishes around organ donation is encouraged. An enduring power of attorney could also be used in cases of temporary incapacity, for example if someone had an accident and was in a coma.