Advance decisions to refuse medical treatment can be made by people over 18. Only advance decisions to refuse life sustaining treatment must be made in writing, and witnessed. They will come into operation if at the material time the person lacks capacity, and they must be directly relevant to current circumstances. Advance decisions cannot refuse basic care, they are not valid if the person is capable of withdrawing the decision, or there is a subsequent Lasting Power of Attorney relating to eh same treatment, or the person has acted in a way inconsistent with that decision.
More information on your right to refuse treatment is available on the NHS Choices website.
Last updated: 14 August, 2017