If capacity is lacking ask if there is a Health and Welfare Lasting Power of Attorney or Court Appointed Deputy, or Advance Decision or Statement of Preferences and Values. If there isn't we must make decisions in the person's best interests.

You must still involve the person in decision making. Find out their current wishes, those they previously may have expressed, and their preferences, beliefs and values that you should take into account in determining best interests.

Family carers have a legal right to be consulted (and you will need them to get the other information in any case).

Health and Welfare Lasting Power of Attorney:
Health and Welfare lasting power of attorney - this is a legal document that allows someone to choose another person to make decisions on their behalf when they lack mental capacity. In effect they have authority to decide as if they were the person themselves.

Court-appointed Deputy:
Court-appointed Deputy is someone appointed by the court to make certain decisions on behalf of a person who lacks mental capacity when the person has not made a Lasting Power of Attorney.

Advanced Decision:
An Advanced Decision is a document signed by the person and a witness which is made to refuse a specific type of treatment at some time in the future. It is legally binding, so long as it complies with the Mental Capacity Act, is valid and applies to the situation concerned. It will take the place of a best interest decision by other people.

Statement of Preferences and Values:
A statement of preferences and values is a less formal document that does not have binding legal force, but which helps you know in general terms what the person would have wanted.