Decision-making for adults lacking the capacity to consent

Sumytra Menon and Calvin W. L. Ho

Healthcare professionals should have a working knowledge of relevant law and policy concerning their own areas of practice, and also concerning medical decision-making, which encompasses the rights of patients and other decision makers. This backgrounder provides a brief overview of law and policy concerning medical decision-making as it applies to adults lacking capacity, and identifies resources readers can turn to for more detailed information and discussions. For an overview of medical decision-making by competent adults, please refer to the sections, ‘Does a Patient Have a Right to Informed Consent?’ and ‘Are There Exceptions to Informed Consent?’ in the backgrounder on Key Aspects of Medical Law in Singapore.

Whilst this backgrounder is focused on healthcare settings, it is important to recognise that the Mental Capacity Act (MCA) applies to all ‘acts in relation to care and treatment’ of a person lacking capacity. Thus, the provisions of the MCA apply equally to the care of people lacking capacity in community- and family-based care settings as they do to the medical treatment of people lacking capacity. There are also specific legal considerations relating to decision-making by, and on behalf of, ‘vulnerable adults’ who are being abused or neglected, or who has been identified as being at risk of abuse or neglect. These provisions are outlined at the end of this backgrounder.

The Mental Capacity Act (MCA)

Reflecting some recent changes in the UK common law jurisdictions of England and Wales, the MCA of Singapore enacted by Parliament in 2008, and which came into force in 2010, creates a framework for making medical decisions on behalf of patients aged 21 or older who lack decision-making capacity. The MCA was amended in 2016 to reflect the emerging need for professional donees and deputies for individuals who did not have close friends or family members they could appoint as their donees or deputies. The Office of the Public Guardian (OPG) administers regulations under the MCA.

The MCA is built upon 5 core principles that outline the requirement to involve adults lacking capacity in the decision-making process, and to enable them to make their own decisions, wherever possible. It is also a requirement that all adults are presumed to have capacity, until a capacity assessment conducted with due regard to their actual lived circumstances has shown that they lack the ability to make one or more decisions for themselves (Re BKR). This empowering approach to decision-making is supported by additional protections introduced under the MCA, including a new criminal offence that outlaws ill treatment of those people lacking the capacity to consent, including neglect of their health or physical needs.

The MCA also offers additional protections for healthcare professionals by clarifying their roles and responsibilities when making decisions on behalf of adults lacking capacity (see paragraphs below). Specifically, the MCA protects these professionals and caregivers from liability for battery when they are performing acts of care and treatment, as long as they have taken reasonable steps to determine that the individual lacks capacity to make such decisions, and their actions are in the best interests of the individual. Such protections do not extend to: (1) civil or criminal responsibility for negligent acts or omissions, (2) enrolling the patient in a clinical trial (unless authorised under a Lasting Power of Attorney (LPA)), (3) use of inappropriate restraint, and (4) acts not within the individual’s professional skills or experience.

Requirements under the MCA for making decisions on behalf of incapacitated patients

The MCA introduces a number of requirements for those making decisions on behalf of adults lacking the capacity to give consent. The concept that underpins these requirements is that of ‘best interests’. The MCA does not provide a definition for what best interests are. Rather it provides a framework consisting of a list of non-exhaustive factors that the decision-maker should consider when making a decision on behalf of the incapacitated person. The MCA best interests framework incorporates aspects of the substituted-judgment standard by requiring the decision-maker to consider the person’s past and present wishes, their values, beliefs, culture and other relevant matters that the person would have considered important regarding that specific decision. This information, along with all other relevant factors, such as the views of loved ones and donees of an LPA, and the benefits and burdens of treatment are weighed up to determine the decision.

If the patient’s wishes, feelings, beliefs, and values are not – or cannot be – known, the MCA best interests test still applies. In these circumstances, the clinical factors will play a more prominent role, and decision-making is likely to be more paternalistic because the patient’s own perspective is absent although the MCA requires the decision-maker to consider any other factors the patient would likely consider if they were able to do so. In similar circumstances in England and Wales, the decision-maker is required to consider any evidence of pain or pleasure displayed by the person that relates to the decision.

The term ‘best-interests’ can sometimes refer both to a legal process, as described in the MCA, for determining whether there is reliable evidence about an incapacitated adult’s values and preferences and how to proceed if there is such evidence, and also to the ethical standard to follow if no reliable evidence exists. It is important for health care professionals to understand the difference between these two uses of the term and to be clear when communicating about them. Evidence of a patient’s wishes, feelings, beliefs, and values should also be sought in the patient’s advance directives, which are explained in the backgrounder, ‘Advance Directives in Singapore’.

Decision-makers with authority under the Mental Capacity Act

When someone lacks capacity and is without any advance directives pertaining to his or her current situation, the Code of Practice of the MCA in Singapore stipulates that the decision makers for this person include caregivers, nurses, doctors, donees of an LPA, and court appointed deputies (within their respective spheres of authority).

Who the decision maker is in a particular situation depends on the nature of the decision that needs to be made. When a decision is made collaboratively within a care team, it is the person who would normally take responsibility for making that type of decision that would be identified as the decision-maker. The following people are potential decision-makers on behalf of a patient who lacks decision-making capacity:

  • Donee of a Lasting Power of Attorney: A patient’s LPA may expressly authorise a specific person to make decisions about that patient’s medical treatment and personal welfare. This person may be someone the patient knows and trusts, or it may be a professional donee with specific expertise, e.g. investment advisors, who are equipped to manage a complex investment portfolio. The decisions made by the donee must be in line with the patient’s best interests, and can be challenged if they are judged not to be so. The MCA does not authorise donees to make decisions relating to life-sustaining treatment or treatment to prevent a serious deterioration in the donor’s health. However, the donee for personal welfare may make care decisions such as where the individual should reside.Many elderly persons prefer to live in the comfort of their own home rather than a nursing home. This move may be contemplated because relatives find it difficult to provide the individual with appropriate medical or nursing care at home. Although this matter has not been litigated in Singapore, the English Court of Protection, which applies the English Mental Capacity Act (on which our own MCA is based) recently decided such a case. An elderly lady (MS) with vascular dementia expressed a strong preference to remain in her own home before she lost capacity. She was detained under the Mental Health Act for her own safety because of self-neglect and hazardous living conditions. The local authority wanted to move her to a nursing home for her own safety and to meet her care needs but MS, and her personal welfare donee opposed this. The court applied the best interests test and decided that given her strong preference, they would try a one-month trial at home to see if she could manage. Although this case is not binding on the Singapore courts, it may be referred to for guidance. It should also be noted that, in Singapore, the MCA was amended in 2016 to allow the court to temporarily suspend a donee’s or deputy’s powers even where no application has been made to the court in relation to the donor or to the person for whom the deputy is appointed by the court. In addition, the court has the power to revoke an LPA under a number of conditions, including when it is satisfied that the donee is behaving in a way that is not in the donor’s best interests.
  • Court-appointed deputies: When a patient has not designated a donee in an LPA, the Court may appoint a deputy to make decisions about medical treatment and personal welfare on behalf of the patient lacking capacity. A court application is required to authorise such a deputy. The deputy may be a paid professional deputy, who is registered with the OPG, and likely to be a lawyer, accountant, or licensed trust company. Again, the decisions made by a deputy must be in line with the patient’s best interests, and can be challenged if they are judged not to be so.
  • Physicians: Decisions concerning a patient’s medical treatment, when no LPA or court-appointed deputy has been designated. Decisions concerning life-sustaining treatment or treatment to prevent a serious deterioration in a patient’s condition can be made only by a physician, even if an LPA or court-appointed deputy has been designated.
  • Nurses and other paid caregivers: Decisions concerning a person’s nursing, social or personal care when no LPA or court-appointed deputy has been designated.
  • Family caregivers: Decisions concerning a person’s personal and social support when he or she is living in a family care environment, and when no LPA or court-appointed deputy has been designated.

In making a best interests decision, the decision-maker must consult anyone named by the person for inclusion in discussions, any caregivers, anyone interested in the person’s welfare (such as family members, close relatives, and friends), any donees and court-appointed deputies. [For best interests decisions under emergency conditions or when a person is experiencing fluctuating capacity, and case examples of personal welfare and medical treatment decisions, see the MCA Code of Practice, Chapter 6 on Best Interests, OPG.]

Decision-making for ‘vulnerable adults’

The 2016 Vulnerable Adults Bill (VAB), which is widely expected to be debated by Singapore’s parliament, will potentially impact on the general legal rules around decision-making in care settings. If introduced into law, the VAB allows additional interventions into the lives of adults lacking capacity for their own protection. A ‘vulnerable adult’ is a person who is, by reason of physical or mental infirmity, disability or incapacity, incapable of protection himself or herself from abuse, neglect, or self-neglect. If identified as ‘vulnerable’, and also judged to have experienced, to be experiencing, or to be at risk of abuse, neglect, or self-neglect, the premises of this adult could be entered, these legal powers would allow an assessment to be carried out, and the person to be removed from their premises, if they lack capacity to consent and it be judged as necessary to protect them. It is expected that these powers will enter into law later in 2017.


Menon, S, The mental capacity act: implications for patients and doctors faced with difficult choices, Annals of the Academy of Medicine, Singapore 2013; 42(4): 200-202,

Johnston, C., and Liddle, J. (2007), ‘The Mental Capacity Act 2005: a new framework for healthcare decision making’. Journal of Medical Ethics, 33, 2: 94-97,

Re BKR [2015] SGCA 26,

Westminster City Council v Manuela Sykes [2014] EWHC B9 (COP)


Sumytra Menon and Calvin W. L. Ho, 'Decision-making for adults lacking the capacity to consent' in Chin, Jacqueline, Nancy Berlinger, Michael C. Dunn, Michael K. Gusmano (eds.), A Singapore Bioethics Casebook, 2 vols (Singapore: National University of Singapore, 2017),