Most health care providers (HCPs) will at some stage have adult patients who are incapable of making their own health-related decision. Various arrangements allow substitute decision-makers to make decisions for such adults. It is important that HCPs understand the hierarchy of substitute decision-makers and when substitute consent is required.

Impaired capacity

An adult has “impaired capacity” to make a decision about a health matter under the Guardianship and Administration Act 2000 (GAA) if they are unable to carry out any part of the below decision-making process:[1]

  • Understanding the nature and effect of decisions about the matter.
  • Freely and voluntarily making decisions about the matter.
  • Communicating the decisions in some way.

It is important to note that an adult may lack capacity regarding some health matters but not others. For instance, they may have capacity to consent to non-invasive treatment but not be able to evaluate the benefits and risks of complicated surgery.

Who is the substitute decision-maker?

If an adult lacks the capacity to make a decision about a health matter, the HCP should identify the appropriate substitute-decision.

For matters other than Special Health Care matters[2] the priority begins with any ADVANCED HEALTH DIRECTIVE (AHD) made by the adult.

An AHD records an adult’s wishes about their future health care. It must be made while the adult still has decision-making capacity.

If the AHD does not apply to the particular health matter, the substitute decision-maker will be, in order of priority:-

View table

Disagreement as to who should be the substitute decision-maker can be referred to the Office of the Public Guardian.[5]

HCPs should sight the appointing instrument to satisfy themselves that it is validly drafted and executed and is applicable to the particular circumstances.[6] Seek legal advice if in doubt.

When making decisions, substitute decision-makers must apply the Health Care Principles[7]. These include that power should be exercised in the way least restrictive of the adult’s rights and only if it is necessary and appropriate for the adult’s health and in the adult’s best interests. The principles also state that the substitute decision-maker must, to the greatest extent practicable, seek and take into account the adult’s wishes and the information given by the HCP.

When substitute consent is not required

Substitute consent is not needed for urgent health care[8] provided it is not reasonably practicable to obtain consent from the adult’s attorney or guardian for health matters (if they have one) or their SHA, except if the health provider knows that the adult has objected to the health care proposed in an AHD.[9]

Additionally, health care to prevent significant pain or distress to the adult can be carried out if the adult has minimal or no understanding of what the care involves or why it is necessary, and the care is unlikely to cause distress that is outweighed by the benefit.[10]

A life-sustaining measure may be withheld or withdrawn for an adult without consent in certain circumstance where the measure is inconsistent with good medical practice.[11]

Minor and uncontroversial health care[12] may also be carried out without consent if the health provider reasonable considers that the health care is required and will best promote the adult’s health and wellbeing.

If the health care is carried out, the HCP must certify in the adult’s records the circumstances enabling the care to be carried out.[13]

In all cases the health care cannot be provided if the health provider knows (or could reasonably be expected to know) that the adult objects to the health care.

Obtaining substitute consent

HCPs must give the substitute decision-maker all information necessary for them to exercise their power in relation to a health matter unless they have a “reasonable excuse” for not doing so.[14] The GAA says that it is a “reasonable excuse” if giving the information might tend to incriminate the HCP.

This includes information about:

  • The adult’s condition(s).
  • The particular form of health care proposed/or carried out.
  • Why it was/will be necessary.
  • Alternative forms of health care available for the condition at the time of treatment and the general nature and effect of each.
  • Long and/or short term significant risk.
  • Why a particular treatment should be carried out.[15]

Potential conflicts

Conflict can occur between family members (or other substitute decision-makers) as well as with the HCP.

If there is a conflict between family members and there is no attorney or guardian, HCPs should allow time (where possible) for them to make the decision, ensuring they have all necessary information.

Where the conflict is between the family members and the HCP again ensure the substitute decision-maker has time and make all efforts to communicate the necessary information. If helpful, explain the HCP cannot provide treatment that is not consistent with good medical practice. If the substitute decision-maker is not satisfied, they can seek a second medical opinion.

If you, as a HCP, believe the substitute decision-maker is not making decision in the adult’s best interest, contact the Office of the Public Guardian for further guidance and consider seeking legal advice.