There may be instances where either an adult family member or spouse is unable to provide consent to medical treatment by reason of mental capacity at the time. Generally, the Supreme Courts in all Australian jurisdictions have an obligation for the welfare of adults who are not competent to consent to health care.
Broadly speaking, there are three categories where an adult may be deemed to have impaired decision making capacity and may include the following:
- temporary decision making incapacity which can include individuals who are affected by sudden and severe emotional trauma, medication, or who may be unconscious;
- permanent decision making incapacity which can include those who have an intellectual disability or suffering from dementia;
- individuals suffering from a mental illness.
The majority of states and territories have laws which may allow a spouse, relative or carer to consent to treatment under certain circumstances.
What happens when a person is suffering from temporary decision making incapacity?
If a person is suffering from temporary decision making incapacity, and they are unable to provide permission for treatment and the treatment is not urgent, the parties who are responsible for the person’s health can wait until the person has regained the capacity to consent to medical treatment. In circumstances where the person’s capacity may be less stable, health carers may have a legal and ethical responsibility to determine the person’s level of understanding at that particular moment, or alternatively, they can wait until the person is able to make a clear decision in relation to their treatment.
However, making an assessment of a person’s ability to make a decision in relation to their medical treatment can sometimes be difficult as was observed in Hunter and New England Area Health Services v A  NSWSC 761 at :
“[T]here is no sharp dichotomy between capacity on the one hand and want of capacity on the other. There is a scale, running from capacity at one end through reduced capacity to lack of capacity at the other. In assessing whether a person has capacity to make a decision, the sufficiency of the capacity must take into account the importance of the decision...The capacity required to make a contract to buy a cup of coffee may be present where the capacity to decide to give away one’s fortune is not.”
Temporary decision making incapacity from medication
Temporary decision making incapacity as a result of medication such as sedatives, pain relief medicine or other types of drugs, should be given consideration as to the effects of such drugs in relation to a person’s decision making abilities. Under such circumstances, the court may be compelled to reject any consent given if the person was incapacitated by drugs, felt pressure to consent, or was not free to question or consider the information necessary to make an informed decision.
Long term decision making incapacity
‘Intellectual incapacity’ is a commonly used term in relation to individuals who are unable to live with some degree of assistance permanently, or for the long term.
When discussing long term decision making incapacity, there may be some individuals who are capable of understanding what is involved with a medical procedure, and those who may not. Individuals who have decision making incapacity, yet, are capable of understanding, have the same rights as any other person who is able to lucidly make a decision on their own. However, the law must be able to determine that the person who has long term decision making incapacity is able to provide consent on their own accord.
A person who is unable to provide consent to medical treatment on their own, may require a substitute decision maker who is authorised by law to act on the person’s behalf for the provision of health care.