Legal aspects of consent to treatment

13 April 2012

Sarah Atkinson and Christine Mercer, Maroochydore

Medical treatment has benefited millions of people, but there are obligations and responsibilities that all medical practitioners must abide by to ensure patients' rights are upheld. So what are the general principles of consent, and is it ever appropriate to act without that consent? This article is written from a Queensland perspective, but similar laws apply throughout other Australian states.

General principles

Some of the general principles established over time through case law and medical practice are:

  • every adult of sound mind has a right to determine what will be done to their body
  • any health care treatment provided without consent is a trespass
  • consent to treatment is distinct from the duty to warn about potential risks of treatment (distinguished by the fact that a failure to warn can give rise to a separate cause of action; see also Doctor's duty to warn about risks)
  • a patient has a right to refuse treatment
  • legislative exemptions permit treatment without consent in limited circumstances (eg treatment provided in an emergency).


The established presumption is that every adult of sound mind has a right to determine what will be done to their body. Before anything is done to that person's body by any medical professional, their consent must be obtained.

Consent to treatment can be implied, verbal and written. However, it must also meet the legal requirements to make it 'valid'.

It is well established by case law and practice that valid consent must meet the following requirements:

  1. Competence/capacity of the patient.
  2. The consent is given voluntarily.
  3. The consent covers the procedure in question.
  4. That the patient was informed in making that decision.

For a doctor or other medical practitioner, the significant issue must be what constitutes valid consent. Outlined below are the legal principles established around the requirements and what they mean:-

1.     Capacity

It was established in the case of MB [1997] SCR 514 at 513 that an "adult is presumed to have the capacity to consent to or refuse medical treatment unless and until that presumption is rebutted".

While capacity is a legal term, doctors are usually the primary assessors of that capacity. Capacity is assessed in respect of the particular decision to be made and at the time when consent is sought. The patient needs to be able to understand the nature and effect of the decision, and demonstrate their understanding by communicating this in some way, for example by way of writing or orally.

2.     Voluntariness

For consent to be valid, it must be given voluntarily. A voluntary decision is one that is made freely by a patient in response to an understanding of the treatment options. The decision must be free from undue pressure, coercion or manipulation.

Treating health professionals and family members may assist the patient to come to a decision. However, assistance must be distinguished from undue influence, with the latter involving a substitution with another person's wishes for that of the patients'. Accordingly, it is for the medical professional involved to be satisfied that it is from the patient, and not from family members or friends, or that undue influences are being placed upon the person.

3.     The consent must cover the act to be performed

This seems obvious, however the treatment provided must fall within the scope of the specific consent that has been given by the patient. In specific circumstances, the consent may be extended to cover further unforeseen treatment such as an emergency. This situation was considered in the case of Murray v McMurchy [1949] 2 DLR 442. In this case a sterilisation procedure was performed when consent had only been given for caesarean section. The court held that the further intervention of the sterilisation was "convenient" rather than "necessary". Therefore consent had not been extended and the further intervention amounted to trespass.

However, in an emergency situation where it will not be possible to provide full advice about the surgery before it is performed, the courts will accept that consent is not required nor should life saving surgery be delayed for this to occur.

This was the situation in Marshall v Curry [1933] 3 DLR 260. In this case, consent had been given by the patient for a hernia operation and during the surgery a testicle was removed. The court held that the further intervention was necessary for curing the hernia and protected the health of the patient. They found that the doctoring of necessity covered the actions of the surgeon to protect him from liability.

4.     Informed consent

When providing advice to a patient about the treatment or surgery to be performed, the following are necessary requirements that a medical professional must cover to ensure that the patient is giving informed consent. The patient should be advised of:

  • the diagnosis
  • recommended treatment
  • material risks (insofar as a reasonable person would expect to be advised of significant risks) in percentage terms associated with:
  • the recommended treatment
  • alternative treatment options
  • no treatment options
  • significant risks to the particular patient.

These policies are from the Queensland Health Policy Statement: Informed Consent for Invasive Procedures and are based on the established case of Rogers v Whittaker (1992) 175 CLR 479 which established the following principle:

"A reasonable person in the patient's position if warned of the risk would be likely to attach significance to it; or if the medical practitioner is or should be reasonably aware that the particular patient if warned of the risk would be likely to attach significance to it."

In that case, the warnings were in relation to the losing of sight with respect to eye surgery that was to be performed. Not unexpectedly, the court held that a person is likely to attach significance to such potential risk because the risk was of permanent damage to one eye when the other eye was already badly damaged (see Doctor's duty to warn about risks for more details on this case).

As modern medicine progress, it is worth bearing in mind that the more elective and discretionary the procedure is, the greater responsibility there is on the doctor to provide information about risks. It is not enough for a doctor to just sign a paper; they must sit down with the patient and make sure that the patient understands the risks involved.

Liability in the absence of consent

The absence of a valid consent is a determining factor in establishing liability for civil assault or trespass.

The Queensland Criminal Code s.245 definition of assault is:

"(1)    A person who strikes, touches or moves or otherwise applies force of any kind to the person of another, either directly or indirectly, without the other person's consent, or with the other person's consent if a consent is obtained by flawed, or who by any bodily act or gestures attempts or threatens to apply force of any kind to the person of another without the other person's consent, under such circumstances that the person making the attempt or threat has actually or apparently a present ability to affect the person's purpose, is said to assault that other person and the act is called an assault."

Protection from liability in the absence of consent

There is protection for medical practitioners from prosecution for either a tort or criminal act.

The protection from civil liability in the tort of trespass is, like the cases above, where the trespass was perpetrated due to the need for emergency treatment or necessity of treatment.

The protection from criminal liability in Queensland is found within the Queensland Criminal Code 1899, s.282:

Surgical operations and medical treatment.
(1) A person is not criminally responsible for performing or providing, in good  faith and with reasonable care and skill, a surgical operation on or medical treatment of;

(a) A person or unborn child for the patient's benefit; or
(b) A person or unborn child to preserve the mother's life, if performing the operation or providing the medical treatment is reasonable, having regard to the patient's state at the time and to all circumstances of the case.

Exceptions to the need to obtain consent

There are also exceptions to the need to obtain valid consent in certain circumstances.

Emergency and necessity

These are established under the common law and statute. The two main exceptions are as discussed above - if the treatment is required to save a person's life, or in an emergency situation where it is impractical to obtain the person's consent. There are also other statutory exemptions:

  • Mental Health Act 2000 (Qld)
  • A person under an involuntary treatment or forensic order to be treated for their mental illness without the consent of the person or anyone else.
  • Transport Operations (Road Use Management) Act 1995 (Qld)
  • Provides for a doctor or health professional to take blood and urine samples to check for alcohol and drug levels from individuals who have been involved in a motor vehicle accident.

Refusal of medical treatment

As discussed above, the general principle of consent is that every adult of sound mind has a right to determine what is done to their body. This includes refusal to undergo medical treatment, including lifesaving treatment.

Lifesaving treatment encompasses two main areas:

  • Treatment that would save the person's life;
  • Treatment that could save an unborn child's life (refusal of treatment by pregnant women).

The main emphasis of the reasoning of the judges in the cases that have come before the courts is that the decision to refuse medical treatment and the capacity of the person should be what is considered, not the eventual outcome (death).

Although capacity has already been discussed, in this situation it is important to elaborate that a person's capacity is assessed in relation to their ability for requisite understanding of the nature and effect of the treatment.  For guidance in this area, we look overseas, where the UK courts found that while a person may be seen as lacking capacity in some areas (eg the case of Re C (Adult Refusal of Medical Treatment) [1994] 1 WLR 290), they may nevertheless be competent in choosing what is or is not to be done to their bodies.  In that case, the Plaintiff, C, was suffering from chronic paranoid schizophrenia and was in a high security psychiatric hospital. He developed gangrene on his leg which could only be remedied by amputation. C refused and said it would be better to die with two feet than live with one. He was deemed to have capacity in regards to understanding the nature and effect of the treatment despite being of unsound mind for other purposes.

There is currently no case law in Australia regarding the refusal of treatment to save an unborn child's life.  However, it is likely that if the issue ever arises, the courts will follow the precedent set in the United Kingdom. In that country, there have been several cases of mothers refusing to undergo caesarean sections that were necessary to save their unborn child's life (Re MB (Medical Treatment) [1997] 2 FLR 426; Rochdale Healthcare NHS Trust v W [1996] 2 FLR 613; Norfolk and Norwich Healthcare NHS Trust v S [1998] 3 WLR 936.) The law has always focused on the mother's right to self determination, despite the moral implications, even if this results in harm to the unborn child.

The UK decisions demonstrate a consistent approach to the issue.  This is in stark contrast to the position in the United States where, in Re Maydun (114 Daily Walsh Rpt 2233 (DC Superior Ct, July 26, 1986)), a mother's wishes were overridden and a caesarean section was ordered to be performed because the court had decided that this was in the unborn child's best interests.  It should be noted, however, that this case has not been followed by all US courts.

However, it is both interesting and important to note that, in the UK, a number of these types of cases have been resolved by challenging the capacity of the mother who is refusing the treatment. In these cases it was found that there was a temporary loss of capacity and the treatment was in the woman's best interest.  For example in Re MB (Medical Treatment) [1997] 2 FLR 426, the Court of Appeal decided that a mother who previously consented to a caesarean section but had a needle phobia and refused the taking of blood samples and administration of anaesthetic, was temporarily incapable of providing consent and gave permission to the hospital to proceed as it was in the woman's best interests.