π Key Information Summary
- Decision-making capacity is decision-specific, time-specific, and domain-specific β a patient may have capacity for simple decisions but not complex ones.
- Capacity is presumed unless there is reasonable evidence to the contrary; the burden of proving incapacity lies with the clinician challenging it.
- The four-abilities framework (understand, appreciate, reason, communicate a choice) underpins capacity assessment in all Australian jurisdictions.
- Supported decision-making must be attempted before resorting to substitute decision-making β aligning with the National Decision-Making Principles (COAG).
- Substitute decision-making legislation varies across Australian states and territories; clinicians must know the hierarchy of decision-makers in their jurisdiction.
- Advance care planning (ACP) documents β including Advance Care Directives (ACDs) β are legally binding in all Australian jurisdictions, though statutory frameworks differ.
- Capacity may fluctuate in palliative care due to delirium, medications (opioids, benzodiazepines), disease progression, or metabolic disturbance β reassess regularly.
- Use validated tools such as the ACE (Aid to Capacity Evaluation) or MacCAT-T to structure and document assessment.
- Referral to psychiatry, geriatrics, or the state/territory Public Guardian is appropriate when capacity is contested or complex.
- All capacity assessments, discussions with substitute decision-makers, and advance care planning conversations must be thoroughly documented in the medical record.
- Aboriginal and Torres Strait Islander patients may conceptualise decision-making through collective and family-based models β cultural consultation is essential.
- In palliative emergencies, treatment that is clearly in the patient's best interests may proceed while a formal capacity assessment and substitute decision-making process is arranged.
Introduction & Australian Context
Capacity and consent are foundational to ethical palliative care practice. Every intervention β from initiating opioid analgesia to forgoing life-sustaining treatment β requires valid consent from a person with decision-making capacity, or a lawful process when capacity is absent. In the palliative care setting, capacity assessment carries particular gravity: decisions frequently involve withholding or withdrawing treatment, accepting comfort-focused care, and planning for end of life.
In Australia, no single national statute governs capacity and consent for medical treatment. Instead, a patchwork of state and territory guardianship and advance care planning legislation applies, unified by the National Decision-Making Principles endorsed by the Council of Australian Governments (COAG) in 2018. These principles affirm that all persons should be supported to make their own decisions wherever possible, and that any restriction on decision-making must be the least restrictive necessary.
The Australian Institute of Health and Welfare (AIHW) estimates that approximately 50,000 Australians receive specialist palliative care each year, with many more receiving generalist palliative support in primary care, aged care, and hospital settings. Among these patients, cognitive impairment β whether from disease progression, delirium, or treatment effects β is common, making capacity assessment a daily clinical task. Studies in Australian palliative care units report that up to 30β40% of inpatients have fluctuating or impaired capacity at any given time.
This section provides a structured approach to capacity assessment, supported and substitute decision-making, and documentation β grounded in Australian law, professional standards, and best-practice palliative care principles.
Capacity Assessment
Legal Presumption of Capacity
In all Australian jurisdictions, every adult is presumed to have decision-making capacity unless there is reasonable evidence to the contrary. This presumption cannot be displaced merely because a patient has a particular diagnosis (e.g., dementia, intellectual disability, mental illness), is elderly, or makes a decision that clinicians consider unwise. The focus must always be on the process of decision-making, not the outcome.
The Four-Abilities Framework
Capacity assessment requires that the person demonstrates four functional abilities in relation to a specific decision at a specific time:
| Ability | Description | Assessment Questions |
|---|---|---|
| Understand | Can comprehend the relevant information about the proposed treatment, including its nature, purpose, and likely effects | "Can you tell me in your own words what we are discussing?" "What are the benefits and risks of this treatment?" |
| Appreciate | Can recognise how the information applies to their own situation β that the proposed treatment is relevant to them personally | "Do you understand that this applies to you and your current illness?" "What do you think will happen if you do / do not have this treatment?" |
| Reason | Can weigh the risks and benefits and engage in a logical process to arrive at a decision | "How did you reach this decision?" "Can you compare the options available to you?" |
| Communicate a choice | Can express a clear and consistent decision by any means (verbal, written, gestural, assistive technology) | "What would you like to do?" The choice must be consistent and sustained, though it may change over time. |
Decision-Specific and Time-Specific Nature of Capacity
Capacity is not a global attribute. A patient may have capacity to consent to a simple blood test but lack capacity to decide whether to forgo chemotherapy. Capacity must be assessed in relation to the specific decision at hand, and at the specific time the decision is needed. In palliative care, where delirium, fatigue, medication effects, and disease progression cause frequent fluctuations, reassessment is essential β particularly before major decisions.
Validated Assessment Tools
When to Seek Specialist Assessment
- Contested capacity β patient, family, and clinical team disagree
- High-stakes decisions β withdrawal of life-sustaining treatment, refusal of blood products, voluntary assisted dying (where legislatively available)
- Underlying psychiatric comorbidity (e.g., major depression, psychosis) that may be treatable
- Suspected undue influence or coercion from family or carers
- Patients under 18 β refer to paediatric-specific capacity/gillick competence frameworks
- Patients subject to mental health legislation (e.g., involuntary treatment orders)
Supported Decision-Making
Principles
The National Decision-Making Principles (COAG 2018) establish that all persons, regardless of disability or cognitive impairment, have the right to participate in decisions affecting their lives. Supported decision-making (SDM) is the preferred approach β it aims to assist the person to make and communicate their own decision, rather than having someone else decide on their behalf.
Practical Strategies for Supported Decision-Making
Supported Decision-Making vs Substitute Decision-Making
| Feature | Supported Decision-Making | Substitute Decision-Making |
|---|---|---|
| Who decides? | The patient, with assistance | Another person, on the patient's behalf |
| Capacity required? | The patient may have partial or fluctuating capacity | Formal finding of incapacity for the specific decision |
| Legal basis | National Decision-Making Principles; inherent in all guardianship legislation | State/territory guardianship and administration acts; powers of attorney legislation |
| When to use | First-line approach for all patients with impaired capacity | Only when supported decision-making has been tried and has failed |
| Documentation | Record strategies used and patient's response | Formal capacity finding, identification of lawful substitute decision-maker |
Substitute Decision-Making
When Is Substitute Decision-Making Required?
Substitute decision-making is invoked when a patient lacks capacity for a specific decision after all reasonable supported decision-making strategies have been attempted, and a clinical decision cannot be deferred. The substitute decision-maker (SDM) must act in accordance with any known wishes of the patient (including advance care directives) and, where wishes are unknown, in the patient's best interests.
Hierarchy of Decision-Makers by Jurisdiction
The hierarchy of substitute decision-makers varies across Australian states and territories. The table below provides a general guide β clinicians should verify the specific hierarchy in their jurisdiction.
| Priority | General Hierarchy (varies by jurisdiction) |
|---|---|
| 1 | Appointed guardian (by tribunal/court) or enduring guardian |
| 2 | Enduring power of attorney (for financial/personal matters, depending on jurisdiction) |
| 3 | Spouse or domestic partner |
| 4 | Adult child (or person who has care of the adult) |
| 5 | Parent (for adults in some jurisdictions) |
| 6 | Other relative or close friend |
| 7 | Public Guardian / Public Advocate (last resort) |
Types of Substitute Decision-Making Arrangements
Appointed by the patient while they had capacity, to make decisions about personal, health, and/or financial matters if capacity is lost. The scope and activation triggers vary by jurisdiction. In some states (e.g., Victoria), a separate appointment may be needed for health decisions.
Appointed by the patient while they had capacity to make personal and health care decisions. Available in NSW, Tas, NT, and ACT. Not available as a separate instrument in all jurisdictions β in some states, EPOA covers health decisions.
When no private arrangement exists, or the arrangement is contested, a guardianship tribunal (e.g., NCAT in NSW, VCAT in Vic, QCAT in Qld) can appoint a guardian and/or administrator. Clinicians, family members, or the Public Advocate may apply.
A written statement by the patient (while capacitous) documenting their values, preferences, and instructions for future health care. ACDs are legally binding in all Australian jurisdictions, though the level of enforceability and formal witness requirements vary.
Duties of the Substitute Decision-Maker
- Act in accordance with the patient's known wishes, values, and preferences (including those in ACDs)
- If wishes are unknown, act in the patient's best interests β considering the patient's values, cultural background, and the least restrictive option
- Consider the patient's current wishes, even if they lack formal capacity β a capacitous expression of preference overrides a prior ACD in most jurisdictions
- Consult with the treating team and, where appropriate, other family members
- Cannot consent to certain treatments (e.g., sterilisation, experimental treatment) without tribunal approval in most jurisdictions
Special Circumstances
- Voluntary Assisted Dying (VAD): Where state/territory VAD legislation applies (Vic 2019, WA 2021, Tas 2022, SA 2023, QLD 2023, NSW 2024), capacity is assessed under a separate, stricter statutory process β the patient must have decision-making capacity at the time of each request. A substitute decision-maker cannot request VAD on behalf of an incapacitated patient.
- Refusal of life-sustaining treatment: A valid ACD refusing treatment is binding and must be followed, provided it applies to the current circumstances. If there is doubt about validity or applicability, seek tribunal guidance.
Documentation
Thorough documentation is a clinical, ethical, and legal imperative. Incomplete or absent records of capacity assessment are a major source of medicolegal risk in palliative care. The following documentation standards apply to all capacity and consent processes.
What to Document for a Capacity Assessment
| Element | Detail |
|---|---|
| Date, time, setting | Capacity is time-specific β record when the assessment was conducted and by whom |
| The specific decision | "Capacity to consent to commencement of subcutaneous morphine for pain management" β not a generic statement of capacity |
| Information provided | Summarise the information given to the patient β diagnosis, proposed treatment, alternatives, risks, benefits |
| Patient's responses | Direct quotes where possible, demonstrating understanding, appreciation, reasoning, and expression of choice |
| Supported decision-making strategies used | What was done to support the patient (e.g., interpreter used, simplified language, multiple sessions, support person present) |
| Clinical opinion | Clear statement: "In my clinical opinion, [patient name] [has / does not have] capacity to [specific decision]" with reasoning |
| Contributing factors | Note reversible factors assessed (delirium, pain, medication effects, metabolic derangement) and actions taken |
| Tool used (if any) | Name of validated tool (e.g., ACE) and score |
| Witnesses | Names and roles of those present during assessment |
What to Document for Consent
- The decision made by the patient or SDM
- Whether consent was informed (information given, patient's understanding confirmed)
- Whether consent was voluntary (absence of coercion or undue influence)
- If a substitute decision-maker was involved: their name, relationship, legal authority (e.g., EPOA, guardian), and confirmation that they were acting within scope
- Any refusal of treatment β document the patient's stated reasons and that the consequences of refusal were explained
What to Document for Advance Care Planning
- Date and participants in the ACP conversation
- Patient's values, goals, and preferences discussed
- Specific treatment preferences (e.g., CPR, intubation, artificial hydration, antibiotics)
- Location of the ACD (copy in medical record, with patient, with SDM, uploaded to My Health Record if applicable)
- Review date β ACP should be reviewed at key transitions (hospital admission, change in condition, patient request)
Special Populations
Paediatrics
Children under 16 may have capacity for specific decisions (Gillick / Fraser competence) β assessed using the same four-abilities framework adapted for developmental stage.
Parental consent is generally required for minors, but mature minors may consent independently if assessed as competent.
In paediatric palliative care, the focus is on family-centred decision-making, with the child's views given increasing weight as they mature.
Referral to hospital ethics committee or guardianship tribunal is recommended when parents refuse treatment that clinicians consider in the child's best interests.
Pregnancy
A pregnant woman with capacity has the right to refuse treatment, even if refusal may harm the fetus β upheld by Australian courts.
Pregnancy does not create a presumption of incapacity. Capacity assessment follows the same four-abilities framework.
In rare emergencies involving a capacitous woman who refuses treatment critical for fetal survival, seek legal advice and hospital ethics input immediately.
Document all discussions regarding treatment decisions in pregnancy with particular care.
Older Adults
Age alone is never a basis for presuming incapacity. Cognitive screening (e.g., AMT, MoCA) should not be conflated with capacity assessment.
Older adults in residential aged care have the same rights to consent and refuse treatment as community-dwelling adults.
Delirium is extremely common in palliative care admissions in older adults β always assess and reverse reversible contributors before concluding incapacity.
Ensure advance care planning discussions are initiated proactively in aged care, ideally before a crisis.
Renal Impairment
Uraemic encephalopathy may impair capacity β particularly in patients declining or withdrawing from dialysis. Capacity assessment should be performed during a period of optimal metabolic state (post-dialysis if applicable).
Patients with end-stage kidney disease who choose to stop dialysis must be assessed as having capacity for this specific decision, and the decision should be supported with advance care planning.
Nephrology and palliative care co-management is recommended for complex decisions around dialysis withdrawal.
Hepatic Impairment
Hepatic encephalopathy (overt or covert) is a common cause of impaired capacity in advanced liver disease. Grade the severity using the West Haven criteria.
Covert hepatic encephalopathy (minimal/MHE) may impair executive function and reasoning while leaving basic understanding intact β formal neuropsychometric testing may be required.
Optimise hepatic encephalopathy treatment (lactulose, rifaximin) and reassess capacity when encephalopathy improves.
Immunocompromised
Immunocompromised patients (e.g., advanced HIV, post-transplant, chemotherapy) may develop CNS infections or treatment-related cognitive impairment affecting capacity.
Delirium is common in immunocompromised palliative patients β distinguish from dementia and medication effects by serial assessment.
In patients with HIV-associated neurocognitive disorders (HAND), capacity may be partially impaired β supported decision-making should be the primary approach.
Aboriginal and Torres Strait Islander Health Considerations
Capacity assessment and consent processes must be culturally safe and recognise the distinct decision-making frameworks of Aboriginal and Torres Strait Islander peoples. In many communities, decision-making is a collective, family-centred process rather than an individual one. Western models of autonomous individual consent may not align with cultural norms, and imposing them without adaptation risks alienating patients and families from care.
Consult with local Aboriginal Health Practitioners, Aboriginal Liaison Officers, or the relevant Aboriginal Community Controlled Health Organisation when conducting capacity assessments for Aboriginal and Torres Strait Islander patients. The Palliative Care Australia (PCA) National Palliative Care Strategy and the AIHW Closing the Gap reports provide further guidance on culturally safe palliative care.
π References
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- 2. Australian Commission on Safety and Quality in Health Care (ACSQHC). National Safety and Quality Health Service Standards. 2nd ed. Sydney: ACSQHC; 2021.
- 3. Advance Care Planning Australia. Advance Care Planning Legislation in Australia. Melbourne: Austin Health; 2023. Available from: advancecareplanning.org.au.
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