Mythbusters: Capacity and consent to medical treatment

Myth 1:

An adult who makes an unusual decision about medical treatment (for example, refusing to go to hospital even though they are having a heart attack and know they might die) lacks decision-making capacity.

No. An adult is presumed to have capacity to make decisions. An adult with capacity is legally entitled to make decisions that others disagree with. However, a decision that a health professional regards as an unwise or unusual decision may be a prompt for clinicians to check the person’s capacity.

Myth 2:

A man with pneumonia and early-stage dementia refuses antibiotics and may die if he does not take them. He cannot decide to refuse this treatment because his dementia means he lacks capacity to consent.

No. A diagnosis of dementia does not of itself mean that a person lacks capacity (although it may prompt an assessment of capacity). If the person has capacity despite their dementia, they are able to lawfully refuse life-sustaining treatment at that time (even if it will result in death).

Myth 3:

A person must prove that they have decision-making capacity, otherwise they cannot make medical treatment decisions.

No. The law ‘presumes’ that a person has capacity unless there is reason to believe they do not. If a family member advises that an aged care resident does not have capacity, the residential aged care facility should take steps to be satisfied of this. This could be done, for example, through a capacity assessment conducted by a medical practitioner with expertise in capacity assessment.
A person is able to make their own treatment decisions and provide valid consent so long as they meet the legal test for decision-making capacity discussed in the factsheet.