Advance care planning in Australia is supported by both statute law (determined by legislation) and common law (determined by judges’ decisions).

Statute law

Legislation to promote advance care planning exists in Australia in all states and territories. However the extent of legislation and type of statutory directive varies. Statutory advance care directives are legislated state-based advance care directives used to outline a person’s preferences for care or appoint a substitute decision-maker.

All states and territories have legislative provisions allowing a person to appoint a substitute decision-maker in the event that they lose capacity.

All states and territories except New South Wales have a legislative regime for advance care directive documents for preferences of care.

The names of advance care directive documents, and the scope of what can be included in the documents expressing health care preferences, vary between states and territories.

Learn more about state and territory-specific advance care planning laws:

Common law

Common law advance care directives are advance care directives that are recognised by the common law (i.e. decisions made by judges in the courts). They do not follow a particular format and there are no formal requirements other than being made voluntarily by a person with capacity.

General common law principles applicable to advance care planning include:

  • every competent adult person has the right to refuse medical treatment, now and in the future
  • adults are assumed to have the decision-making capacity to consent or refuse consent to medical treatment.

Advance care planning in Australia has relied on the common law respect for autonomy, advance care directives and substitute decision-making. However, the legal standing of common law advance care directives has only been tested in New South Wales. In 2009, the New South Wales Supreme Court ruled that common law directives are valid ways for people to indicate their objection to particular treatment(s).

In all other jurisdictions, there is currently no common law ruling in relation to non-statutory advance care directives. However, in all jurisdictions common law documents provide evidence of the person’s views and preferences.

This is referred to as ‘having evidentiary weight under common law’ and means that if a doctor provides treatment to a patient that is contrary to their written preferences, this can be used as evidence in any court action.

Validity of advance care directives

An advance care directive will be strengthened if:

  • it is consistent with the person’s preferences
  • the person has expressed these preferences previously
  • the person appoints a substitute decision-maker who has a clear understanding of their preferences and is willing to be a strong advocate for them
  • it is a written document
  • there is evidence that when signed and dated, the person was competent and not unduly influenced (witnessing may provide further support, as may the witness’ qualifications)
  • it is recent - a more recent advance care directive may be regarded as more valid because it provides more certainty about its currency
  • it relates to a current condition - an advance care directive that clearly contemplates the current clinical circumstances will reduce doubt about its applicability
  • it is appropriately worded - an advance care directive will be stronger if it avoids vague or imprecise language.

Although there is no requirement for a common law advance care directive to be documented, signed, dated and witnessed, the lack of a written document (i.e. a spoken directive) will likely give rise to genuine and reasonable doubts about validity and current applicability.

Applicability of advance care directives across states and territories

In general, valid advance care directives will apply in other states and territories in Australia although there may be some limitations and additional requirements. Each state and territory manages this issue differently.

Decision-making capacity

Formal advance care planning is only legally possible when a person is competent or has decision-making capacity. Without this, they are unable to make informed decisions.

An adult is presumed to have decision-making capacity unless there is evidence to the contrary.

A judicial declaration of incompetence may be global or limited to certain areas such as financial matters, personal care or medical decisions.

Decision-making capacity is task-specific. Components of decision-making capacity include:

  • the ability to understand information
  • the appreciation of the relevance of that information to the situation
  • the ability to reason or weigh up the risks and benefits
  • the ability to express a choice

People who lack decision-making capacity

It is still possible to conduct advance care planning with individuals who have lost decision-making capacity.

If they have previously legally appointed a substitute decision-maker, there are certain documents that can be completed on the person’s behalf.

Through supported decision-making, a person with limited decision-making capacity can still be involved in advance care planning conversations. They may still be able to discuss certain aspects, such as their overall values and what they consider a reasonable outcome, even if they are unable to discuss specific things.

Decision-making standards

The relevant legislation for each jurisdiction sets out the decision-making principles that the substitute decision-maker should follow when making decisions.

Substituted judgement

Substituted judgement is about making decisions that the person would have made in the circumstances. This means 'to stand in the shoes' of the person who lacks decision-making capacity.

The decision-maker should use the following principles to assist with this:

  • the decision-maker is required to fully take into account the person’s views (current where appropriate, and previous - written or oral) and make the decision they truly believe the person would make in the current circumstances
  • the decision-maker needs to consider whether the outcomes of care and treatment, as they understand them to be, are consistent with the values and preferred outcomes that have been previously expressed by the person.

Whilst substituted judgment in many jurisdictions is the standard for decision-making on behalf of a person lacking decision-making capacity, there are circumstances where the person’s preferences are unknown, and cannot be inferred. This includes circumstances where the person may not have ever had capacity. In these circumstances 'best interests' standards are utilised.

Best interests

The ‘best interests’ standard of decision making requires decision-makers to make the decision that provides the maximum anticipated benefit to person and entails weighing the relative benefits and harms of different treatment options.

This generally includes making decisions that provide: maximum anticipated benefit to the person while minimising restrictions; and that seek to optimise care and protection of the person. There is variation as to what should be included in a best interests decision-making standard.

See also

Last updated: September 2023