Definition – A healthcare substitute decision-maker (SDM) is a person who has legal power to make medical decisions on another’s behalf if they are unable to make these decisions for themselves. The role of SDMs for medical decisions is very significant as decisions about healthcare intervention or non-intervention, can include consenting to, withholding and/or withdrawing life-sustaining treatments.

The Role as a SDM
As a substitute decision-maker, you have some important responsibilities that may include:

• speaking with the person about their preferences and values for health care

• making important decisions on their behalf if they are ever unable to communicate

• encouraging them to make an advance care directive

People are called upon to act as substitute decision-maker (SDM) when a family member or friend is approaching end of life and are no longer able to make their own medical decisions. SDMs may be formally appointed to the role, or automatically eligible through a family relationship (eg spouse) as stipulated under legislation, which varies across Australian States and Territories.

A SDM will not need to make the decision if the person without capacity has an Advance Care Directive that applies to the situation. Where a person has impaired capacity and there is no Advance Care Directive, a substitute decision-maker will be required to make the treatment decision.

In Australia, a person’s ability to appoint an SDM, and for the SDM to act appropriately, depends on the level of awareness of the requirements of these roles. However, as determined in a study by Advance Care Planning Australia, the low to moderate knowledge of the SDM role in Australia indicates this may be problematic.
Who may be a substitute decision-maker and the terminology given to them differs throughout Australia. Find out more about who may be a substitute decision-maker in your state or territory at End Of Life Law in Australia.

Tips for SDM’s
It is important for you to understand the beliefs, values, beliefs, health care preferences and acceptable outcomes of the person who has appointed you.

The best way for you to understand these things is by Talking openly and honestly with the person who has appointed you is the best way for you to understand these things. To help you, we’ve created resources to help you get the conversation started. YourLifeTalks.com

Ensure you understand and respect their preferences for health care, living well and end of life decisions.
If you and the person have conflicting beliefs, it is important to be honest with them. Keep in mind that you may be called upon to advocate for them, and if your beliefs differ, it may be better for them to choose another person.
Talk about any potential issues that may arise with family members who have different views. How will you manage any disagreements that may arise? If you are chosen as the SDM for that person, will their family and friends be informed?

The SDM role presents challenges about knowing the best decision to make under the given circumstances. Making decisions about end of life health care are reported as being the most stressful. If you are in a situation needing to do this, ask doctors, nurses and care workers for health care information about the person. A SDM should fully understand the various treatments that are available, and it is particularly important to understand life-prolonging treatment options.

The following pages explore Australia’s laws relating to:

Withholding and withdrawing life-sustaining treatment from adults
Guardianship law
Children and end of life decision-making
Futile or non-beneficial treatment

Substitute decision-making for adults (by State and Territory):
Australian Capital Territory
New South Wales
Northern Territory
Queensland
South Australia
Tasmania
Victoria
Western Australia
Emergency medical treatment (by State and Territory):
Australian Capital Territory
New South Wales
Northern Territory
Queensland
South Australia
Tasmania
Victoria
Western Australia

Complaints and dispute resolution (under ‘Emergency medical treatment’ on each State and Territory page).

Capacity and consent to medical treatment in Australia’s laws are discussed here.

Despite Australia’s ageing population and the provision of legislation in every Australian jurisdiction allowing for substituted medical decision-making, there are identifiable gaps in available information and support to assist people to make these weighty decisions with confidence and ease.

Advance Care Planning Australia offers a range of online resources and a free helpline to support people making medical decisions for others, but highlights that doctors and health professionals play a critical role in supporting and educating the Australian public regarding both substitute decision-making and advance care planning.