Except in limited circumstances, health professionals must obtain a patient’s consent before undertaking any health procedures. This is so, even when the proposed treatment would clearly benefit the patient, and when failure to treat the patient may result in harm that may have been avoided. The principle applies not only to treatment but also to diagnostic and investigative procedures.

The requirement for consent recognises that competent individuals are entitled to make their own healthcare decisions – even if their decisions may sometimes appear to the health professional as not being in their best interests. Where the patient lacks capacity, the law supplies a substitute decision-making framework.

If the consent of a patient or substitute decision-maker is not obtained, the health professional can be subject to an action in trespass to the person (commonly called assault or battery), unless an exception applies. A claim of this kind, unlike a claim in negligence, can be brought without needing to prove damage or loss.

Further, a health professional who treats a patient without informing them adequately about the procedure can be subject to an action in negligence (see ‘What information must be given to a patient?’, below).

Consent to medical treatment may be given by the patient if they have capacity. If they do not, consent may be provided by the patient’s parent/guardian (if they are a child) or a substitute decision-maker.

Adults

Adults are presumed to have capacity to consent to medical treatment. An adult may lack capacity if they are unable to:

understand, retain, or use/weigh information relevant to the decision; or
communicate their decision.

For example, a person who is unconscious would lack capacity. A person’s medical condition or disability may also deprive them of capacity, though all adults (including those with medical conditions or disabilities) are presumed to have capacity unless proven otherwise.

If a person does not have capacity to make a medical treatment decision, the Medical Treatment Planning and Decisions Act 2016 (Vic) (‘MTPD Act’) specifies who has authority in Victoria to make such decisions on behalf of the patient as ‘medical treatment decision-maker’. This may be a person appointed in advance by the patient, or (if no-one is appointed) a person specified in the MTPD Act who has a continuing relationship with the patient. If there is no medical treatment decision-maker, then:

The Victorian Civil and Administrative Tribunal (VCAT) may appoint a guardian to make medical treatment decisions under the Guardianship and Administration Act 2019 (Vic); or Victoria’s Public Advocate can make significant treatment decisions without the need for a guardianship order.

If a medical treatment decision-maker or guardian makes a medical treatment decision, they must

follow the process set out in the MTPD Act and make the decision they reasonably believe the represented person would have made.

For further information on the MTPD Act and guardianship, see Chapter 8.5: Guardianship and medical treatment.

Children

If the person is a ‘child’ (under 18), generally either parent or a guardian may consent to a procedure, and the parent or guardian is entitled to the same information as an adult patient. In the case of non-therapeutic procedures (such as sterilisation or donation of organs), court authority is required; the parent alone cannot consent.

A child may also be able to consent if they are sufficiently mature to understand the procedure. This depends on the child’s age and level of maturity, and the particular procedure. Mature minors can consent to simple procedures, such as a vaccination. On the other hand, greater maturity and understanding will be required for procedures that are higher risk or are considered by some to be sensitive, such as contraception or commencement of hormonal therapy for gender dysphoria.

Consent may be express (in writing or orally) or implied. However, it must be given voluntarily and cover the act proposed. Under the law of trespass, the patient or their substitute decision-maker must be informed of the broad nature of the procedure to be performed prior to giving consent unless an exception applies.

In many cases, consent is implied from a person’s actions, such as rolling up a sleeve to receive a flu vaccine. This type of consent is generally effective, though the law may be less ready to accept that consent was present if the procedure poses a substantial risk. Hospitals usually require patients undergoing surgery to sign a consent form that often states the person has been given information about the procedure and has consented to it. The fact that a person has signed such a form is evidence they were informed and consented to the surgery, but it is not conclusive. A court may still examine the circumstances in which the form was signed to determine what the person was really told and understood.

Patients, including children with capacity, may also give advance care directives consenting to, or refusing, particular treatment in the event that they lose capacity. For further information, see Chapter 8.5: Guardianship and medical treatment.

In an emergency, medical treatment may be administered without consent, provided that the treatment is necessary to address an urgent medical situation. It is not enough that the procedure is merely convenient. This principle applies under the common (judge-made) law and also under the MTPD Act (see s 53).

Further, the person must not have refused the treatment by a valid advance care directive. For example, there have been cases in which Jehovah’s Witnesses have refused blood transfusions in advance.

It is not always necessary to obtain the consent of the patient’s medical decision-maker in an emergency, although where practicable, it is prudent to do so.

A patient must be given adequate information to enable them to decide whether to consent to a healthcare procedure. While the law of trespass to the person requires only that the patient is informed in broad terms of the nature of the procedure, the law of negligence (see Chapter 10.1: Negligence and injury) requires a broader range of information to be provided by a health practitioner who seeks a patient’s consent. That information includes:

information about the patient’s condition;
the options for investigation or treatment and their advantages and disadvantages, including what is likely to happen if nothing is done;
the material risks of the treatment; and
what the doctor recommends.

Many court cases alleging negligence concern the type and amount of information that needs to be given about the material risks of a proposed procedure. The law requires a patient to be warned of risks that are likely to be significant to them or to a reasonable person (see Rogers v Whitaker [1992] HCA 58). Whether a risk is material depends on:

the person’s condition;
the nature of the treatment (more information may be needed for a ‘cosmetic’ procedure than for surgery that is clinically indicated for the patient’s health or wellbeing);
the seriousness or likelihood of the risk (serious risks like death, stroke or paralysis should be mentioned even if they are remote; similarly, minor injuries like bruising after venepuncture (entry into a vein) may be material if they are frequent);
the patient’s desire for information (questioning, anxious patients may need to be given more information); and
the general surrounding circumstances (less information may be justified for life-threatening or urgent procedures than for those that can be delayed).

The test is whether the risk in question is so serious, or so likely to occur, that it is likely to influence the decision of a reasonable person whether to agree to the procedure; or whether the health professional knows, or should know, that the risk would be significant for the particular patient.

Ultimately, this depends on the circumstances of a particular case. As a patient, it is advisable to question health professionals thoroughly, to resolve any doubts about the consequences of a treatment or procedure

In Rogers v Whitaker [1992] HCA 58, the High Court explained that a failure to warn of material risks did not render consent invalid. Rather, the failure may found an action in negligence if the patient is able to establish that they would not have undergone the procedure had they been warned of the relevant material risk.

There are several cases in which less information may be justifiable.

The first case is an emergency. Here, treatment may be given without any information, if it is necessary to protect the person’s life or health.

The second case is a health professional’s limited discretion (therapeutic privilege) not to disclose information where they have reasonable grounds to believe that disclosing the information may harm the person (e.g. if the individual is suicidal). Even in this case, however, a health professional may not be justified in withholding information if a patient asks a specific question.

A third case may exist where the person waives the right to be given information. There are some suggestions in older cases that a doctor should not be required to burden a patient with unwanted information about risks; however, the scope of this exception has not been significantly explored in subsequent cases. Further, it should be noted that a patient may not have sufficient understanding of the possible risks to make a meaningful decision to refuse to hear information about them. Even if this is an exception to the requirement to disclose material risks, the individual must still be given sufficient information about the procedure to give an effective consent to it.

Treatment for mental illness, including electroconvulsive therapy and neurosurgery

Special principles apply to decisions about treatment for mental illness as a patient of a designated mental health service. Still more principles apply to treatment involving electroconvulsive therapy and neurosurgery. For further information, see Chapter 8.4: Mental illness.

Consent and information

Introduction

Who may give consent?

How is consent given?

Emergencies

What information must be given to a patient?

When may less information be given?

Introduction

Access to medical records