However, “best interests” decision making should always be collaborative. Whoever is the best interests decision maker, there is an obligation in the MCA to consult “others engaged in caring for [the patient] or interested in their welfare” about best interests, and in particular to make sure that the decision maker is as fully informed as possible about the patient’s wishes, values and beliefs, and what they want for themselves (MCA s4(6) and 4(7)). For decisions about medical treatment, “best interests” is to be interpreted as much wider than simply medical risk / benefit, and includes social, emotional and all other aspects.
Often, for serious decisions, it will be appropriate to have one or more meetings to discuss the decision among the professionals and others, such as the family, friends and others who are engaged in caring for the patient or interested in their welfare. Disputes about best interests can be resolved by the Court of Protection, and the onus should be on the public body proposing the treatment to take any dispute to Court, so there should be no costs to the family.