The general rule is that a patient is presumed to have the capacity to make medical and other decisions on their own behalf unless and until it is established that they do not have that capacity. Today’s correspondent asks whether that has been reversed in WA by the Mental Health Act 2014 (WA) s 15(1). The section says:

For the purposes of this Act, a person has the capacity to make a decision about a matter relating to himself or herself if another person who is performing a function under this Act that requires that other person to determine that capacity is satisfied that the person has the capacity to —

(a) understand any information or advice about the decision that is required under this Act to be provided to the person; and

(b) understand the matters involved in the decision; and

(c) understand the effect of the decision; and

(d) weigh up the factors referred to in paragraphs (a), (b) and (c) for the purpose of making the decision; and

(e) communicate the decision in some way.

My correspondent says:

In general of course all people have the presumption of capacity under common law until that presumption is rebutted.

Practically that means for clinicians the onus is on us to disprove that presumption through our assessment of a patient. That’s very reasonable though … this creates those problematic situations where we haven’t had time to fully assess a person’s capacity or they won’t cooperate with that assessment and then they wish to leave. In general, the presumption of capacity applies and we generally can’t hold them against their will…

To me this [s 15] essentially reverses the presumption of capacity so in grey area situations where the clinician is unsure or hasn’t had time to assess the patient (or patient won’t cooperate) then as far as the MHA is concerned, the patient does not have decision making capacity.

What do you think of this? Would you agree this section 15 of the WA MHA is effectively reversing the presumption of capacity with respect to mental health patients?

The Mental Health Act

One has to admit that s 15 is not the norm. One would expect the section to say a person has capacity unless a relevant person has determined that they do not have any of the capacities listed in (a) to (e); not that the person must be satisfied that they do.

I can see the argument and its appeal to WA doctors (see No power to detain a patient just because it’s good for them (January 22, 2023) and Publication on detaining patients in the ED (August 29, 2023)) but like all exercises in statutory interpretation the section has to be read in context. In particular s 15 appears in Part 5, Division 1 of the Act. That Division is titled ‘Decision making capacity generally’.  Also in that Division is s 13(1) which says:

For the purposes of this Act, an adult is presumed to have the capacity to make a decision about a matter relating to himself or herself unless the adult is shown not to have that capacity.

Both s 13 and s 15 have to have work to do. An interpretation that says they are inconsistent (one presumes capacity, the other presumes incapacity) cannot be right.

The Explanatory Memorandum filed with the Mental Health Bill 2013 (the Bill that became the Act of 2014) says:

Clause 13 relates to an adult making a decision about a matter with respect to himself or herself. The Act creates a presumption that an adult has decision making capacity, unless shown not to have that capacity. Whether an adult has the requisite capacity to make a decision under the Act is a decision for the person or body making a determination under clause 15…

Clause 15 is a threshold test in that it sets out the requirements for a person to be considered to have capacity to make decisions under the Act that are not treatment decisions. The intention is to require decision makers to consider whether or a not a person who is being asked to make a treatment decision understands the nature and consequences of the decision they are being asked to make. If an adult does not meet the requirements in clause 15, then the presumption in clause 13 is rebutted in relation to that adult, ie they do not have decision making capacity…

As I read it, s 13 of the Act (cl 13 of the Bill) reinforces the presumption of capacity. If a ‘person who is performing a function under this Act that requires that other person to determine’ whether the patient does in fact have capacity they have to examine them.  They do not have to be ‘satisfied’ that the person does not have capacity, they have to be ‘satisfied’ that they do have all the capacities listed.  In a sense that shifts the ‘onus of proof’ – the question is not ‘are you sure they don’t have capacity?’ but rather ‘are you sure they do?’

Further the Act has limited application in a hospital ED where a patient may want to leave before they have been examined or may not want to co-operate with the staff. The Mental Health Act is about the treatment of mental illness. A person is mentally ill if and only if (s 6; emphasis added)):

… the person has a condition that —

(a) is characterised by a disturbance of thought, mood, volition, perception, orientation or memory; AND

(b) significantly impairs (temporarily or permanently) the person’s judgment or behaviour.

A person who is intoxicated or has a head injury is not mentally ill. 

Section 15 is about capacity to make decisions generally. Section 18 is about the capacity to make medical treatment decisions, but it is in similar terms to s 15. It says ‘A person has the capacity to make a treatment decision … if another person who is performing a function under this Act that requires that other person to determine that capacity is satisfied that the person has the capacity to’ understand and weigh up the factors listed in s 18(a) to (e). For the purposes of the Mental Health Act, ‘treatment’ means (s 4):

…the provision of a psychiatric, medical, psychological or psychosocial intervention intended (whether alone or in combination with one or more other therapeutic interventions) to alleviate or prevent the deterioration of a mental illness or a condition that is a consequence of a mental illness, and does not include bodily restraint, seclusion or sterilisation;

The Guardianship and Administration Act

The Guardianship and Administration Act 1990 (WA) also deals with medical treatment which is defined (s 3) to mean:

(i) medical or surgical treatment, including a life sustaining measure or palliative care; or

(ii) dental treatment; or

(iii) other health care;

Section 4(3) says:

 Every person shall be presumed to be capable of —

(a)            looking after his own health and safety;

(b)           making reasonable judgments in respect of matters relating to his person;

(c)            managing his own affairs; and

(d)           making reasonable judgments in respect of matters relating to his estate,

until the contrary is proved to the satisfaction of the State Administrative Tribunal.

Urgent treatment can be given to a person who cannot make ‘reasonable judgments in respect of the treatment’ (s 110ZI).  What constitutes ‘reasonable judgments’ is not defined but I would suggest a court would not accept that it means a judgement that the doctors agree with; that would be inconsistent with a fundamental principle of law and bio-medical ethics – the respect for patient autonomy.  I would infer that a ‘reasonable judgement’ is one where the patient has the capacity to receive and consider advice before making a decision to accept or reject treatment even if ‘the reasons for the refusal were rational or irrational, unknown or even non-existent’ (In re T (Adult: Refusal of Treatment) [1992] EWCA Civ 18 cited with approval in H v AC [2024] NSWSC 40). The test is a functional one – ie is there capacity – not an outcome test – is the decision one that others consider ‘a good or wise decision’ (PBU & NJE v Mental Health Tribunal [2018] VSC 564).

Discussion

Although the language is ambiguous, I do not think s 15 of the Mental Health Act 2014 (WA) reverses the presumption of capacity. It may lower the threshold to be met to set aside the presumption but to in deny the presumption would be inconsistent with s 13.

For doctors in WA ED departments, even if it did, it would only do so with respect to patients that doctors suspect are mentally ill, not who require other treatment.  A person who has arrived in ED but wants to leave is presumed to be competent under the Guardianship and Administration Act 1990 (the ‘GA Act’). In MGP [2020] WASAT 65, at [34] Presiding Member Marillier said:

… The statutory presumption of capacity is a fundamental principle in the GA Act and serves to protect persons who are the subject of proceedings under the GA Act from having their decision-making capacity removed from them and a substitute decision-maker appointed for them under the act. Because of the significant consequences for an individual of having their decision-making capacity removed from them and a substitute decision-maker appointed for them under the GA Act, clear and cogent evidence is required to rebut the statutory presumption of capacity.

Consistent with that is my suggested interpretation of the term ‘reasonable judgments’ in relation to health care. The fact that a person does not want to accept treatment offered, or remain in an ED until examined, is not sufficient to show that they are not capable of making ‘reasonable judgements’ even if in the doctor’s opinion they are not making reasonable judgements.

Conclusion

My conclusion is that the effect of ss 15 and 18 of the Mental Health Act 2014 (WA) is that there is a lower bar to overcome the presumption of capacity when it comes to people who are mentally ill and where treatment for a mental illness is being considered, than there is in other cases of medical treatment where ‘clear and cogent evidence is required to rebut the statutory presumption of capacity’. 

But even under the Mental Health Act there would have to be some reason – some evidence – to show that the person had considered the factors listed and why they came to the conclusion that they were not satisfied that the person had all of the capacities listed. If they just hadn’t yet examined the person that would mean everyone in the ED, in fact everyone in the community, would be presumed to be not competent which would be an anathema to law, ethics and community standards.

This blog is made possible with generous financial support from the Australasian College of Paramedicine, the Australian Paramedics Association (NSW), Natural Hazards Research Australia, NSW Rural Fire Service Association and the NSW SES Volunteers Association. I am responsible for the content in this post including any errors or omissions. Any opinions expressed are mine, and do not necessarily reflect the opinion or understanding of the donors.