Originally published June 2011 / Revised March 2021
Patients have the right to decide whether to consent to investigations and treatments. This means investigations and treatments may be administered by healthcare professionals only with valid consent or with a court order, except in cases of emergency when consent cannot be obtained.
Consent is valid when it is given by a person with the necessary mental capacity or competency (in Québec that is a person 14 years or older). Questions about capacity to provide consent may arise when the patient is an adult who suffers from a condition that impairs his or her mental state.
There is a legal presumption that a patient is capable of consenting to investigation and treatment unless there is reason to believe otherwise. Individuals suffering from mental disorders or significant developmental disabilities may still have sufficient capacity to give consent.
Established legal criteria are used for determining whether a patient has the capacity to consent. In some jurisdictions the criteria have been developed by the courts. In other jurisdictions the test for determining capacity to consent is set by legislation. Although the wording of the legal tests may differ, an individual who is able to understand the nature and anticipated effects of the proposed investigation or treatment and available alternatives, including the consequences of refusing, is typically considered mentally capable to give consent. Because incapacity can be temporary, it may be necessary to reassess capacity to consent at appropriate intervals.
When discussing an intervention with an individual with a mental disorder or developmental disability, it is prudent to consider possible deficits in language, memory, or attention that may affect the patient's ability to understand the information being conveyed. A physician who is uncertain whether a patient has the capacity necessary to provide consent in a non-emergent situation may wish to obtain a second opinion from a colleague.
It is prudent for physicians to document in the medical record the basis for the conclusion that a patient is incapable of consenting. This may include reference to the elements of the applicable test for capacity, the dates and results of any capacity assessments performed, and any second opinions sought.
The failure to obtain proper consent prior to investigation or administering treatment in non-emergent situations can have significant legal implications for physicians, including the possibility of a medical regulatory authority (College) complaint, or a civil legal action alleging battery or negligence. Detailed notes in the medical record can provide valuable evidence that the physician took reasonable care to assess capacity in a particular case.
Where it is determined that a patient is incapable of consenting to investigation and treatment, the next question for the treating physician becomes who is authorized to consent on the patient's behalf.
Legislation in most provinces and territories provides a means of obtaining substitute consent when the patient is deemed to be incapable. The legislation typically sets out a hierarchy or prioritized list of individuals authorized to give or refuse consent on behalf of the patient. It is necessary to begin by seeking substitute consent from the highest-ranking person on the list, typically the patient's spouse, parent, or children. If the patient has no immediate family, or the highest-ranking person is not readily available or willing to make a decision within the required time, substitute consent can be obtained from the next highest-ranking and available person on the list. It is important for physicians to be generally familiar with the criteria for substitute decision making in their jurisdiction.
Where no substitute consent legislation exists (i.e. Nunavut, Northwest Territories, Manitoba, and New Brunswick), and where the patient has no valid advance directive that applies to the treatment in question, strictly speaking only the court or someone appointed by the court may consent to or refuse treatment on the patient's behalf. In practice, however, where prompt investigation and treatment is clearly required and there is general agreement that the recommended care is in the patient's best interests, many physicians will proceed on the basis of the family's approval.
It is preferable to amicably resolve issues concerning capacity to consent through discussions with the patient and the family. If disagreement persists among family members, or if the investigation or treatment carries significant risks, CMPA members are encouraged to seek timely and advance legal advice from the CMPA.
Consent to medical assistance in dying
Medical assistance in dying (MAID) is legal in Canada, provided eligibility criteria and safeguards are met. A substitute decision-maker cannot consent to MAID on behalf of an incapable patient.
In limited circumstances, a patient can waive the requirement to confirm their consent to MAID at the time it is administered. Patients who meet all eligibility criteria and safeguards for MAID and for whom natural death is reasonably foreseeable may make advance arrangements in writing with their medical or nurse practitioner before losing capacity. The advance agreement will be invalided if the person subsequently refuses or demonstrates resistance to MAID in their words, sounds, or gestures.
Issues with capacity
Legal processes exist in each jurisdiction for patients or their representatives to dispute a clinical finding that the patient is incapable of providing consent.
In most provinces and territories, an application must be brought before the courts to resolve issues concerning a patient's capacity to consent. Some jurisdictions have specialized tribunals, commonly referred to as "consent and capacity boards," to make such determinations. CMPA members with medico-legal questions about such issues should call the Association for advice.
Generally, substitute decision-makers (SDMs) are required by law to act in accordance with wishes expressed by the patient when capable (including advance directives, wishes expressed verbally, etc.). Some legislation specifies that if those wishes are unknown, the substitute decision-maker must act in accordance with the patient's best interests. The patient's values and beliefs may also be required to be considered.
From time to time, physicians may find themselves disagreeing with an SDM's treatment choice. As a preliminary step, consultations with other physicians or legal counsel may be of assistance. Discussions with an ethics board or ethicist might also be useful in attempting to resolve the disagreement affably. Keep in mind that many ethics boards and ethicists may not be prepared to make a final decision, but rather favour attempting to facilitate dialogue between the parties.
Members are encouraged to contact the CMPA immediately when faced with any difficult consent and capacity issues or when uncertain about what resources might be available in the event of disagreement with an SDM or among family members.