Health professionals come to different conclusions about the ‘right thing to do’ when applying the terms of a living will to the way they treat a patient, says new research from Bristol University, published in the British Medical Journal.

People write living wills to set out the sorts of medical treatments they want (or don't want) if they become mentally incapacitated and are unable to speak for themselves.  People assume that if they write a living will the doctors will carry it out - though in the UK there is no statutory law compelling them to do so.

In the Bristol study, doctors and nurses were shown the living will of a factitious patient in which the patient refuses consent to antibiotics in certain circumstances.  They were then given a scenario in which this same person has become mentally incapacitated and has developed pneumonia.  They were then asked what they considered the ‘right thing to do’.

Approximately half the participants thought that treating the patient with antibiotics was the right thing to do and the other half though the patient should not be treated.

The reasons participants gave for treating the person were either that it was consistent with the living will to treat her or that her quality of life was worth preserving regardless of the living will.  Those making the former case looked to the ambiguity of words in the living will such as ‘life threatening’ and ‘irreversible’.

Those opposed to treatment cited respect for the autonomy of the patient as the main reason.

Dr Trevor Thompson, clinical lecturer at Bristol University, and co-author of the study said:“This research highlights the fact that living wills, though made in good faith, will always be subject to interpretation by doctors and other carers.  In some cases this amounts to a flagrant breach of patient autonomy, while in others it reflects the exercising of good clinical judgement.

“Doctors need to find additional ways of understanding the perspectives of incapacitated patients who finds themselves needing critical care such as drugs, surgery or ventilation.  Even if compliance with living wills was made a legal requirement for doctors it would still be difficult to enforce the law due to the inherent complexity of these situations and the ambiguity of medical language.”

Adherence to advance directive in critical care decision making: vignette study by Trevor Thompson, Rosaline Barbour and Lisa Schwartz.  BMJ Volume 327, pp 1011