Capacity: the essentials

• Having capacity to make healthcare decisions requires patients to be able to understand, retain and weigh information about the decision to be made.
• In assessing a patient’s capacity, it is important to focus on their ability to make a decision - including their planning, reasoning and judgement.
• Patients with limited capacity may still be able to make decisions with support. Wherever possible, supported decision-making should be preferred over substitute decision-making.

Capacity refers to a person’s ability to make a decision for themselves, including about their healthcare. A patient must have capacity before they can provide a valid consent. All adult patients are presumed to have capacity.

The word ‘competence’ may also be used for the same concept. If someone has the requisite capacity to make a decision, they may be described as competent.

A person has capacity to make a healthcare decision if they can understand the nature and consequences of the decision to be made. A person must also be able to communicate their decision, verbally or by other means.

What must a person be able to do?

In determining whether your patient has capacity, you should consider whether your patient can do the following with the information provided:

The law presumes people have capacity to make decisions about their healthcare at 18 years of age (except in South Australia where capacity is presumed from 16 years of age). Before reaching this age, some children can develop the capacity to make decisions about their healthcare. For more information on this topic, please see Avant’s factsheet: Children and Consent.

This means you can presume adults have capacity unless there are circumstances or behaviours that may lead you (or another person) to believe your patient does not have the capacity required to make the particular decision.

A patient’s capacity may fluctuate over time and could be influenced by factors ranging from lack of sleep or the time of day, to pain, being affected by alcohol or drugs (including medication), or brain injury or psychiatric illness.

Capacity is ‘decision-specific’, and patients may have capacity to make some decisions but not others. For example, the capacity required to consent to a complex surgical procedure will be different from that required for a routine examination or to start taking a new medication. When assessing capacity, it is important to consider the specific decision and how risky the procedure or treatment is.

What if a person has an intellectual disability or other illness?

A patient who has an intellectual disability, mental health issue, neurodegenerative disorder or other illness should not automatically assumed to lack capacity to provide consent for their own healthcare. The legal test for capacity is based on what the patient is able to do and understand, not their condition. People with disabilities and illnesses often have the capacity to consent to or refuse medical treatment, depending on the nature of the decision.

Capacity is about a person's decision-making ability, not the decision they make

When assessing a patient’s capacity to make decisions, it is important to focus on their abilities to make a decision (outlined above) rather than the actual decision they make. If you do not agree with the decision or do not think it is rational, it does not mean the patient lacks capacity.

However, you should not completely disregard decisions you think are unwise, unusual, or out of character for your patient. This could be a flag to check your patient’s capacity and to refer them for a formal assessment if necessary.

Use the following steps as a guide when assessing whether your patient has capacity to make a healthcare decision:

1. Evaluate your patient’s mental state and cognitive function

You could do this by using a cognitive assessment tool to identify and quantify the presence and severity of any cognitive impairment. This assessment can give you a sense of how to proceed with the rest of your discussion. It may indicate that a detailed discussion about a particular decision is not possible at that time. Or it may indicate the person can make some decisions, but not others.

2. Ask your patient to explain the decision at hand

After giving you their decision, ask the person to explain, their understanding of why the decision needs to be made, what choices are available, what the benefits or risks are of the different choices, and what they understand or feel about the possible outcome of the choice. A simple “I understand” does not confirm that the person has understood your discussions. Consider open questions, such as:

• Can you tell me why you are thinking about this treatment over the other options we discussed?
• What are the possible risks with the treatment and how might you deal with them if they occurred?
• What do your family and friends think of the treatment?

3. Assess your patient's ability to make a decision

Testing for capacity not only involves checking for understanding, but also for the ability to make a decision. Listening to the person’s planning, reasoning and judgement will alert you to whether the person understands their choices and the possible consequences of their decision.

Make sure to carefully document your conclusions and the basis for them. If capacity is still unclear, it may be helpful to seek a second opinion from a medical practitioner who has experience in this area, such as a geriatrician or mental health specialist.

All states and territories recognise supported decision-making. If you are concerned that your patient may not have capacity to make a particular healthcare decision, consider whether they could make the decision with appropriate support before concluding that they lack capacity. 

Support may include using an interpreter, providing information in simpler language, using pictures or written information, allowing additional time, or discussing fewer options at a time. 

A patient may also receive assistance from a support person, such as a trusted family member, friend, carer or advocate. Their role is to help the patient understand the options, consider their preferences and communicate their decision. They must not make or impose the decision themselves. 

If the patient can make the decision with appropriate support, the decision remains the patient’s, even if it differs from the views of their support person. Take care to ensure the support person is helping the patient express their own preferences rather than influencing or imposing the decision.

Capacity may fluctuate. If the decision can safely be delayed and you think your patient may regain capacity, allow time for this to happen and reassess their capacity. 

If the decision cannot safely be delayed, or the patient is unlikely to regain capacity within the required timeframe, the next steps will depend on the law in the relevant state or territory. This includes: 

• whether treatment can be provided without consent 
• how any advance care planning document or previously expressed wishes apply 
• who is legally authorised to make the decision on the patient’s behalf. 

The correct substitute decision-maker may be a family member or friend, an enduring guardian, attorney, guardianship tribunals or the Supreme Courts in each state and territory. It is not automatically a person’s next of kin. Refer to Avant’s substitute decision-maker factsheet for the relevant state or territory. If you remain unsure, seek medico-legal advice. 

You can find additional resources including articles, podcasts, and webinars on the Avant website under Consent: Avant insights and resources - Avant by doctors for doctors 

Visit https://capacityaustralia.org.au for resources on decision-making capacity.

For medico-legal advice, please contact us here, or call 1800 128 268, 24/7 in emergencies.