Health practitioners need their patient’s consent before providing medical treatment. 

However, anyone can experience an injury or illness that means they are unable to make decisions, either temporarily or permanently.

If a patient does not have capacity to make a decision about the proposed treatment the health practitioner must first check if the patient has consented to or refused the treatment in an instructional directive in a valid advance care directive.

If not, the health practitioner will ask the patient’s medical treatment decision maker, to make the medical treatment decision for the patient.

See Identifying the medical treatment decision maker.

How to make decisions when acting as someone’s medical treatment decision maker 

You must make the medical treatment decision you reasonably believe the person would have made, if they had decision-making capacity to make the decision.

Victoria's Medical Treatment Planning and Decisions Act 2016 sets out the process for this.

1. Consider the preferences and values of the person

You must first consider any valid and relevant values directive in an advance care directive that the person made, if any.

Next, you must consider any other relevant preferences that the person has expressed, and the circumstances in which those preferences were expressed. 

For example, they may have written down their wishes or  told close family members. 

If you cannot identify any relevant preferences of the person, you must give consideration to the person’s values. They may have expressed their values, or you may be able to infer them from their life. 

2. Consider the proposed medical treatment

You must also consider:

• the likely effects and consequences of the medical treatment, including the effectiveness of the medical treatment
• whether the likely effects and consequences are consistent with the person’s preferences or values
• whether there are any alternatives, that would be more consistent with the person’s preferences or values (including refusing medical treatment).

3. Consultation

You must consult with anyone that you reasonably believe the person would want you to.

4. Act in good faith and with due diligence

You must act in good faith and with due diligence.

5. Promote personal and social wellbeing

If you cannot find out the person’s preferences or values, you need to make a decision that promotes their personal and social wellbeing. You need to consider the person’s individuality and whether the proposed treatment or any alternatives would be better in promoting the personal and social wellbeing of the person.

If asked to make a medical treatment decision that relates to treatment for mental illness, contact OPA for more information.