A Best Interest decision (Section 4, Mental Capacity Act 2005) is a legally directed process that must be followed when a person has been assessed to lack capacity to make a specific decision at a specific time. By describing the process as ‘Best Interest’ it is purposeful reminder to all those involved that it is a decision that should be made in the Best Interest of the individual, and not any of the other involved parties.
With this in mind, it is therefore absolutely essential that the individual’s preferences, thoughts, wishes, values and beliefs are established before any Best Interest decision can be made.
Lessons from case law
One of the most frequently referenced court cases on this topic can be found in the Supreme Court case of Aintree University Hospital NHS Foundation vs James (2013, UKSC 67). The judgement states:
23. A person who has the capacity to decide for himself can of course make decisions which are not in his own best interests and no doubt frequently does so. Indeed, the Act provides that a person is not to be treated as unable to make a decision simply because he makes an unwise one: section 1(4). But both at common law and under the Act, those who act or make decisions on behalf of a person who lacks capacity must do so in his best interests: section 1(5). How then is it to be determined whether a particular treatment is in the best interests of the patient? […]’
The judgement goes on to reference the Act’s direction on how Best Interest is to be established before noting:
24. […] However, as the Court of Appeal later recognised in Re S (Adult Patient: Sterilisation) [2001] Fam 15, there can only logically be one best option. The advantage of a best interest’s test was that it focused upon the patient as an individual, rather than the conduct of the doctor, and took all the circumstances, both medical and non-medical, into account (paras 3.26, 3.27). But the best interests test should also contain “a strong element of ‘substituted judgment'” (para 3.25), taking into account both the past and present wishes and feelings of patient as an individual, and also the factors which he would consider if able to do so (para 3.28). This might include “altruistic sentiments and concern for others” (para 3.31). The Act has helpfully added a reference to the beliefs and values which would be likely to influence his decision if he had capacity. Both provide for consultation with carers and others interested in the patient’s welfare as to what would be in his best interests and in particular what his own views would have been. […]’
39. […] in considering the best interests of this particular patient at this particular time, decision-makers must look at his welfare in the widest sense, not just medical but social and psychological; they must consider the nature of the medical treatment in question, what it involves and its prospects of success; they must consider what the outcome of that treatment for the patient is likely to be; they must try and put themselves in the place of the individual patient and ask what his attitude to the treatment is or would be likely to be; and they must consult others who are looking after him or interested in his welfare, in particular for their view of what his attitude would be.
This judgement clearly sets out the responsibilities placed upon the decision-maker in the Best Interest process, placing emphasis on the need to put the individual’s thoughts, wishes, values and beliefs in the ‘driving seat’ of what decision to make.
This point has been revisited and highlighted within many cases, including the case held before Mr Justice Hayden in NHS South East London Integrated Care Board and JP (2025, EWCOP 8, T3), wherein it was found that there had been a failure to apply Best Interests in the meaning of the Act, undermining the individual’s ‘inviolable right to be valued, respected and treated ethically’, leading to the individual to suffer compromised dignity. The judge also raised significant concerns around the untimely manner in which the case had been raised before the Court of Protection.
Through these cases, and others, we are not only reminded of the legal responsibility of those in the position of ‘decision maker’ to ensure that the individual’s thoughts, wishes, values and beliefs are upheld, but also that if there is any conflict in this matter, it must be escalated to the Court of Protection without delay.