5B: BEST INTERESTS AT COMMON LAW AND UNDER THE MENTAL CAPACITY ACT

The evolution of best interests at common law

  1. The power to make medical welfare decisions in the best interests of an incapacitated adult was first formally recognised by the courts in England in a 1990 case in the House of Lords. In Re F,667 the issue was whether a profoundly mentally disabled young woman who was living in a hospital setting and having a sexual relationship with a man in circumstances where contraception was considered unsuitable, should have a hysterectomy to prevent her becoming pregnant and having a child. The House of Lords held that the common law doctrine of necessity allowed the medical treatment of adults who were unable to give consent. Treatment or care, which might otherwise be an assault upon a person who lacked capacity to agree to it, was lawful, provided it was in the best interests of the person concerned.

  2. This jurisdiction was first limited to declarations of lawfulness related to medical treatment668 but later was extended to non-medical issues as well, such as a person’s residence and contact with others. The resulting body of law is described by Fennell as one of the most dramatic manifestations of judicial creativity in recent years.669 The COP recently expanded the declaratory jurisdiction to cover the withdrawal of life-sustaining treatment from someone who was in a minimally conscious state, not a permanent vegetative state.670

667 Re F, above n 125. There were a series of cases involving sterilisation of disabled women at that time, for example, T v T [1988] 1 All ER 613 at 625. There was further recognition of the declaratory jurisdiction in a Court of Appeal decision In Re F (Adult: Court’s Jurisdiction) [2001] Fam 38, Dame Butler-Sloss held that although an 18-year-old mentally handicapped woman did not come within the guardianship principles of the MHA 1983, and was too old for the court’s wardship jurisdiction, the court was entitled under the inherent jurisdiction and bests interests doctrine to make declaratory judgments when there was risk of possible harm in respect of an adult who lacked capacity to make decisions.

668 The declaratory jurisdiction has also been exercised for the continuance of artificial nutrition and hydration: Airedale NHS v Bland, above n 165.

669 P Fennell “Mental Capacity” in LO Gostin, P Bartlett, P Fennell and others (eds) Principles of Mental Health Law and Policy (Oxford University Press, Oxford, 2010) at 168.

670 M v Mrs N [2015] EWCOP 76 (Fam) Hayden J. The Court had to consider whether the best interests of Mrs N, who suffered progressive and degenerative impact of multiple sclerosis to receive life sustaining treatment by means of clinically assisted nutrition and hydration (CANH) currently provided by a (PEG) tube.


  1. In Re F, the House of Lords, in the same judgment, adopted the Bolam test for medical negligence671 as the standard governing health providers’ determinations of best interests.672 This meant that the task of determining a patient’s best interests was effectively delegated to the medical profession, making the question a clinical one to be judged by a narrow “not negligent“ test.673 The adoption of this standard, referred to as the “Bolamisation” of medical law,674 has been adopted in different areas of medical law besides negligence, including informed consent and when determining “Gillick” competence for consent from children.675 More recently, the Bolam test has been put to rest with regard to the duty of a doctor to disclose information to the patient for the purpose of obtaining informed consent. 676

  2. The case law on necessity and best interests continued to evolve after Re F and many of these developments were codified in the MCA. The need to have a wider best interests criterion was recognised in English Law Commission reports, culminating in the enactment of s 4 of the MCA.677 In modern parlance, when applying the MCA both doctors and lawyers refer to “clinical” best interests – that is, what a doctor might think best in the clinical circumstances of a person’s case – as a distinct concept. It contributes to decisions about, but remains distinguishable from, a person’s best interests as understood under the MCA.

671 Bolam v Friern Barnet Hospital Management Committee [1957] 1 WLR 582. The Bolam test is as follows: A doctor is not guilty of negligence if he has acted in accordance with a practice accepted as proper by a responsible body of medical opinion.

672 Re F, above n 125 at 78.

673 M Donnelly “Best Interests, Patient Participation and the Mental Capacity Act 2005” (2009) 17 Med Law Rev 1 at 3.

674 M Brazier and J Miola “Bye-bye Bolam: A Medical Litigation Revolution?” (2000) 8 Medical Law Review 85 at 90.

675 Gillick v West Norfolk and Wisbech Area Health Authority [1986] AC 112. See also, M Dunn, I Clare, A Holland and others “Constructing and reconstructing “Best Interests”: an Interpretative Examination of Substitute decision-making under the Mental Capacity Act” (2007) J Soc Welf Fam Law 117.

676 Montgomery v Larnarkshire [2015] UKSC 11. This case concerned a pregnant diabetic patient who was not warned by her consultant about the risk that her baby, being relatively large size in relation to the mother’s pelvis, would have shoulder dystocia. The doctor thought the mother would opt for a caesarean section, which the doctor considered to not be in her best interests.

677 Szerletics, above n 209.


Best interests under the MCA
  1. The MCA therefore now provides the framework for the application of the best interests test and the Court of Protection provides important guidance on its interpretation. Although a comprehensive definition of a person’s “best interests” is deliberately not provided by the MCA, it sets out a number of rules which must be followed. These require that a decision- maker must consider all relevant circumstances, and in particular:678
  • Equal consideration and non-discrimination: Determinations must not be made merely on the basis of the person’s age or appearance, or on the basis of unjustified assumptions from the person’s condition or behaviour;

  • Regain capacity: Consider whether the person is likely to regain capacity and, if so when that is likely to occur;

  • Permitting and encouraging participation: Encourage the person to participate as fully as possible in the decision before making it for the person;

  • Best interests decisions in relation to life-sustaining treatment: These decisions must not be motivated by a desire to bring about the person’s death;

  • Person’s past and present wishes, feelings, beliefs and values: This includes consideration of written statements, the person’s beliefs and values, and any other factors that the person would be likely to consider if they were able; and

  • The views of other people: Consult a number of people including carers, holders of lasting powers of attorney, deputies and anyone else named by the person.
Constructing decisions
  1. Assessing best interests (or “benefit” under Scottish law) is described by Adrian Ward, a Scottish lawyer, as a process of “constructing decisions” on behalf of the person who cannot make the decision themselves.679 Neither the MCA nor its Code of Practice provides an indicationoftherelativeweighttobegiventothevariousfactors.680 Forexample,itispossible for two individuals conscientiously to apply the s 4 “checklist” and come to different views as to where the person’s best interests lie, but both views could be “reasonable”. Under s 5 of the MCA, both could then act on their beliefs to carry out routine acts of care and treatment safe in the knowledge that they were protected from liability.681 The duty to consult the person and others is wide. In Winspear v City Hospitals Sunderland NHS Foundation Trust,682 the Court emphasised that, where the duty to consult under s 4(7) of the MCA has arisen and has not been complied with, there will be no defence available under s 5 of the MCA.683 While the duty to consult is not absolute, the person carrying out an act in connection with care and treatment will not be able to proceed as if they had the consent of the individual lacking capacity.

678 The factors listed here in s 4 of the MCA are set out in the Law Commission Report at 160. See Appendix C for s 4 of the MCA.

679 The methodology for assessing benefit under the Adults with Incapacity Act (Scotland) is set out in A Ward above n 128 at Chapter 17 (A Douglass, Interview with Adrian Ward, Edinburgh, 29 May 2015).

680 See, for example, MCA Code of Practice, above n 285 at 86 [5.5] to [5.7]. Note that the framework under the MCA creates the role of a best interests assessor. The design of the Act is that if a person is a decision-maker whether the person making the decision is acting as a family carer, a paid care worker, an attorney, a court appointed deputy or a health professional. As long as these acts or decisions are in the best interests of the person who lacks capacity to make the decision for themselves, or to consent to acts concerned with their care or treatment, then the decision maker or carer will be protected from liability under ss 5 and 6.

681 Example given in Ruck Keene and Butler-Cole, above n 201. In the ZH v Commissioner of Police, above n 415 at [40], the Court of Appeal emphasised that the defence afforded to health and social care professionals delivering routine acts of care and treatment is “pervaded by the concepts of reasonableness, practicality and appropriateness”.

682 [2015] EWHC 3250 (QB).

683 The provisions of MCA s 5 are based on the common law doctrine of necessity as set out in Re F, above n 125. See MCA Code of Practice, above n 285 at Chapter 6: “What protection does the Act offer for people providing care and treatment?” In addition, s 6 places clear limits on the use of force or restraint by only permitting restraint to be used for example, to transport the person to their new home, where this is necessary to protect the person from harm and is a proportionate response to the risk of harm. It is beyond the scope of this report to consider whether statutory protection for carers and health practitioners, as provided for in ss 5 and 6 of the MCA would be appropriate or necessary in New Zealand’s medico-legal environment under the no-fault treatment injury provisions of the Accident Compensation Act 2001.


  1. In weighing the factors under s 4 of the MCA, the Courts have endorsed a “balance sheet” approach whereby the relevant benefits and burdens of a particular course of action are listed and, only where the “account” can be said to be in “significant credit” can a decision be said to be in a person’s best interests.684 Although case law has confirmed that there is no hierarchy between these factors, in that the weight attached to each will vary in the circumstances of each case, certain factors can become “magnetic” and tilt the balance.685
The person’s wishes, feelings, beliefs and values
  1. Section 4(6) requires the decision-maker:
So far as is reasonably ascertainable to consider –
  1. The person’s past and present wishes and feelings (and, in particular, any relevant written statement made by him when he had capacity),

  2. The beliefs and values that would be likely to influence the decision if he had capacity, and

  3. The other factors that he would be likely to consider if he were able to do so.
  1. The practical effect of s 4(6) is to require the decision-maker to attempt to ascertain what the person’s subjective preferences would have been, had they been able to express them. This does not require the decision-maker to make a formal substitute judgement, by trying to put themselves in the shoes of the person, as the matters itemised in subsection (6) are merely considerations when deciding what the person would have wanted. Therefore, although there is an element of substituted judgement involved, the MCA represents a compromise between the objective and subjective approaches to decision-making for people with impaired capacity.

  2. Where the person’s reliably identifiable wishes and feelings suggest a course of action that would be profoundly risky for them, the relative weight to be given to the person’s wishes and feelings has been contentious,686 as the statute does not set out a hierarchy of these considerations.687
Conflict between past and present wishes and feelings
  1. Nor does the MCA expressly indicate whether it is the present or the past wishes and feelings of a person that should be given priority, and neither are determinative. There may be situations where there is a conflict between the person’s own views pre- and post-incapacity. A person’s past preferences may not be relevant if their present circumstances have changed radically. Ward suggests that a person should “not be treated as irrevocably ‘owned’ by the past adult, and ... present wishes and feelings should prevail”.688 For example, under an advance directive,689 a person, while capable, may express a strong preference that they would not wish to live with profound disabilities but when in that situation may appear to be contented.690

  2. Such conflicts are an inevitable feature of the hybrid, participatory approach taken to best interests by the MCA and do not diminish the value of its approach.691

684 Re A: (Mental Patient: Male Sterilisation) [2000] 1 FCR 193 at 206, Thorpe LJ.

685 Re M [2009] EWHC 2525 (FAM) At [35] Munby J lists the relevant factors, including: the degree of the person’s incapacity, for the nearer to the borderline the more weight should be attached to their wishes and feelings; the strength and consistency of the person’s view; and the extent to which P’s wishes and feelings, if given effect to, can properly be accommodated within the Court’s overall assessment.

686 A Ruck Keene and C Auckland “More presumptions please? Wishes, feelings and best interests decision-making” (2015) Eld LJ 293.

687 MCA Code of Practice, above n 285 at 81 [5.38].

688 A Ward Greens Essential Legislation: Adults with Incapacity Legislation (Thomson Reuters/W Green, London, 2008) at 15.

689 The requirement to take account of the person’s past wishes in s 4(6) of the MCA may be conflict with the advance refusal provisions provided for in ss 24-26 of the MCA.

690 M Donnelly “Determining Best Interests under the Mental Capacity Act 2005” (2011) 19 Med Law Rev 304 at 311; Re Martin (1995) 538 N.W n.99.

691 Donnelly, above n 673 at 2.


Whose best interests?
  1. Although there is a general obligation to consult certain people during the course of a best interests assessment, the overall aim is to have a better understanding of what would be in the individual’s best interests.692 The court has accepted, however, there are certain situations where the interests of others are inseparable from the interests of the protected person and therefore seem to carry moral relevance when making decisions on the person’s behalf. In the case of Re Y,693 a woman with severe disabilities was deemed to be the best suitable donor for her sister who suffered from a bone marrow disorder. The Court held that the required operations were in Y’s best interests as she would tend to prolong her sister’s life and Y would continue to receive emotional, psychological and social support from her sister in return.

  2. There have also been cases of substituted “financial altruism”. In Re G (TJ),694 Morgan J directed the court-appointed deputy of an elderly woman who lacked capacity, to make maintenance payments from her funds to her daughter on the basis that the payments were in the best interests of Mrs G. The approach taken in this case was a substituted judgment approach. Both the previously expressed wishes of Mrs G, as well as the hypothetical wishes and feelings that she would express if she were able, were considered.695

  3. The impact of the best interests decision on others is considered relevant regarding the court’s power to make gifts. In David Ross v A,696 Senior Judge Lush authorised the payment of A’s brother’s school fees from A’s clinical negligence award in circumstances where it was clear that A’s well-being depended in large part upon the well-being of her family as a whole. A, who was severely disabled at birth, will never have the capacity to make or contribute to a decision of this kind and reliance was placed on the views of the professional deputy who managed her funds and knew her family well.
Best interests and “the patient’s point of view”
  1. Aintree University Hospital NHS Foundation Trust v James697 was the first decision of the Supreme Court of the United Kingdom under the MCA. It concerned a seriously ill man who lacked capacity to make decisions about his medical treatment. The hospital sought a declaration that it would be in the best interests of Mr James to withhold specified life- sustaining treatments should they be needed. His family opposed the application. The High Court declined the application and the Court of Appeal reversed that decision. Mr James died following a cardiac arrest but in view of the importance of the issues and the different approaches taken in the lower courts, the Supreme Court gave Mr James’s widow leave to appeal. The Supreme Court was unanimous in rejecting the widow’s appeal but disagreed with the Court of Appeal’s reasoning, preferring the approach adopted by the High Court.

  2. In Aintree, the Supreme Court addressed the question of how doctors and courts should decide when it is in the best interests of the person to be given, or not given, treatments necessary to sustain life. The Court held that the question for the Court is whether it is in the patient’s best interests to receive the treatment, rather than in their best interests to have it withheld or withdrawn. Where there is complete agreement among clinicians that life-sustaining treatment should not be offered and their stance is confirmed by an independent expert who would also be unwilling to provide such treatment, there is, in effect, no best interests decision to be taken, as there is no treatment option available to the patient. Lady Hale corrected the Court of Appeal’s suggestion that the test for considering a patient’s wishes and feelings is an objective one of what a reasonable patient would think. As Lady Hale noted: 698
    The purpose of the best interests test is to consider matters from the patient’s point of view. That is not to say that his wishes must prevail, any more than those of a fully capable patient must prevail. We cannot always have what we want. Nor will it always be possible to ascertain what an incapable patient’s wishes are. Even if it is possible to determine what his wishes were in the past, they may well have changed in light of the stresses and strains of the current predicament.
  3. 5.41 Lady Hale confirmed that “the preferences of the person concerned are an important component in deciding where his best interests lie.” She went on to state:699
    ... 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 on what his attitude would be. [Emphasis added]

692 Mental Capacity Act 2005, s 4(7).

693 Re Y (Mental Patient: Bone Marrow Donation) [1997] Fam 110.

694 Re G (TJ) [2010] EWHC 3005 (COP) Morgan J.

695 Re G (TJ), above n 694, at [35].

696 [2015] EWCOP 46.

697 Aintree, above n 164.

698 Aintree, above n 164 at 18 [45].

699 Aintree, above n 164 at 15 [36].


  1. Some cases have suggested that, in certain circumstances, the person’s wishes and feelings will be determinative. In Re S,700 Hazel Marshall QC J accepted that the person’s views are not ordinarily paramount, but went on to say that where a person’s wish is not irrational (in the sense of being a wish that a person with full capacity might reasonably have), is not impracticable as far as its physical implementation is concerned, and is not irresponsible, having regard to the extent of the person’s resources, then a presumption arises in favour of implementing their wishes, unless there would be some sufficiently detrimental consequence for the person to outweigh this.
Best interests and proposed law reform under the MCA
  1. It has been argued that the Supreme Court judgment in Aintree has given a new impetus to the centrality of the person at the heart of the best interests process.701 However, the recent House of Lords’ report on the operation of the MCA notes that one of the problems was that the wishes and feelings of the person lacking capacity were not routinely prioritised in best interests decision-making and, instead, “clinical judgements or resource-led decision-making predominate”.702

  2. Moreover, for pragmatic reasons, it will not be possible for every decision by a person lacking capacity to be the subject of a best interests determination under the MCA.703 The House of Lords report found that “the best interests principle is widely praised but its implementation is problematic”.704 There have been a number of cases where insufficient recognition has been given to the person’s wishes and feelings when making a best interests decision, as well as to the presumption that living or contact with family is in the person’s best interests.705

  3. The Law Commission has now proposed that the MCA should be aligned, as far as possible, with the CRPD. However, the UN Committee has effectively rejected best interests decision- making, saying national laws must ensure that the person’s “rights, will and preferences” are respected, rather than decisions being based on an objective assessment of their best interests.706 While the MCA refers to “wishes and feelings” in this context, the CRPD adopts the term “will and preferences”.707 The Law Commission did not consider that there was any substantial difference between these phrases, although they are deployed for different purposes.708 The Law Commission has recommended that there should be a presumption that the person’s wishes and feelings will be followed, to make the best interests standard more compliant with the CRPD.709 In Wye v Mr B, Peter Jackson J defended the existing provision in the MCA and questioned this proposal: 710
    ... my respectful view is that the Law Commission proposal would not lead to greater certainty, but to a debate about whether there was or was not "good reason" for a departure from the assumption. To elevate one important factor at the expense of others would certainly not have helped the parties, nor the court, in the present case. All that is needed to protect the rights of the individual is to properly apply the Act as it stands.

700 [2008] EWHC (16) FAM.

701 House of Lords Select Committee, above n 3 at [99].

702 House of Lords Select Committee, above n 3 at [104].

703 IM v LM, above n 591 at [77].

704 House of Lords Select Committee, above n 3 at [90].

705 Cases include: Hillingdon v Neary, above n 462, (which was referred to extensively in the House of Lords report). In G v E and others [2010] EWHC 621, although a Local Authority’s decision to remove a mentally incapacitated adult from a continuing placement with a person who had fostered him as a child breached his rights under Article 5 and 8 of the European Convention on Human Rights, it would be in his best interests to continue at the residential care unit to which he had been transferred until there was a final hearing to consider whether he might be returned to the foster carer.

706 CRPD General Comment No. 1, above n 242 at [20]-[21].

707 Article 12(4) of the CRPD uses the formulation ‘rights, will and preferences’. The ALRC formulation follows the spectrum of decision-making based on the will and preferences of a person, through to a human rights focus in circumstances where the will and preferences of a person cannot be determined. See Chapter 2 Supported Decision-making.

708 Law Commission, above n 199 at 165.

709 Law Commission, above n 199 at 164.

710 Wye Valley v Mr B, above n 172 at [17].


Summary
  1. In New Zealand, the phrase “best interests” is found in both the PPPR Act and in Right 7(4) of the HDC Code, but it cannot be regarded as a specified legal standard for decision-making of the kind codified in the MCA.711 Nor does New Zealand law actively encourage supported decision-making as envisaged in the CRPD, and in the case law of the COP applying s 4 of the MCA.712

  2. The UK Supreme Court decision of Aintree713 provides some insights into how the best interests test might apply to end-of-life decision-making under the court’s inherent jurisdiction in New Zealand.714 However, withdrawal or withholding of treatment type cases rarely come before the High Court under the inherent jurisdiction in New Zealand. Most “best interests” decisions in respect of a person’s care and welfare and property are made by those substitute decision-makers appointed under the PPPR Act or the Family Court under that jurisdiction. Or, they do not come before the courts at all, such as treatment and healthcare decisions that need to be made for people who lack capacity under Right 74) of the HDC Code. The net result is that the decision-making process for reaching “best interests” decisions – where the decisions are made by others – is largely invisible.

  3. The scheme of the MCA and its Code of Practice is pragmatic as it allows the great majority of decisions to be made in the person’s best interests by informal decision-makers, such as carers and family without recourse to the court or for the appointment of formal decision- makers at all.715 It is also consistent with supported decision-making principles under the CRPD, to provide reasonable accommodation of support measures that are tailored to an individual’s needs.716 To this end, New Zealand should develop a decision-making standard that is similarly consonant with both human rights obligations and the need to ensure there is a clear and transparent process for decision-making that takes into account a person’s will and preferences.

711 There has been limited discussion about the meaning of “best interests” in the New Zealand context within the parens patriae jurisdiction,
see Re G [1997] 2 NZLR (HC) and Auckland Healthcare Services v L [1998] NZFLR 998 (HC).

712 See Re M (Best Interests) and Wye Valley v Mr B, case examples discussed in Chapter 2E Supported decision-making in practice and in English case law.

713 Above n 164.

714 N Peart “Withholding Treatment” [2014] NZLJ 117 at 119.

715 Interview with Lady Brenda Hale, Deputy President, Supreme Court of the United Kingdom (A Douglass, London, 6 May 2015).

716 B Hale, discussing discrimination on the grounds of not providing reasonable accommodation (Toulmin Lecture, Kings College London, 12 March 2015).

  © 2019 Alison Douglass