Some of it depends on the age of the person. An elderly person would probably be assessed by a geriatrician initially, maybe have a MOCHA done by an OT and also have to speak to a psychiatrist.
Anyone else, over the age of 18 would probably be spoken to by the oncologist initially, then assessed by a psychiatrist, then the person's solicitor would probably get them assessed by another psychiatrist before finally ending up at a hearing where medico-legal judges would decide.
It’s really not that easy to have someone declared incompetent or mentally unsound, just because they want to decide for themselves what treatment the do/don't want. Any doctor who wanted to take this route would have to be fairly certain that it would lead to the judgement that they were looking for. It’s extremely costly as well for the NHS Trust or public hospital (if you’re not in the UK).
I nursed someone who had refused treatment for a very easily cured cancer. Long story short, they died, and I often think about them, and all the other patients I’ve lost. It’s heartbreaking and I know that people have this whole thing about medical practitioners don’t have feelings and need to maintain professional boundaries, but it’s hard. When you look after somebody for a long time, care for them to the best of your ability, get to know their family, it’s bloody heart-wrenching.
Ultimately though, the patient is always at the centre of the treatment plan and their wishes, assuming they are of sound mind, will be taken in to account. Good practitioners will want to help the person to draw up a plan for their care, especially for later on, once the disease has really taken hold and the patient may not be able to verbalise their wishes at that point.
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