■ Physician-patient:

Communicating effectively with patients to optimize their care

Informed consent

Young female patient meeting with a female physician. The physician is reviewing a document with her patient.
Published: March 2021 /
Revised: November 2022
12 minutes


It is a basic accepted legal principle that "every human being of adult years and of sound mind has the right to determine what shall be done with his or her own body."1 Outside of taking action to save life or limb in emergency situations, physicians may do nothing to or for a patient without valid consent. This principle is applicable to all medical and surgical treatment, and diagnostic investigations involving the patient.

Inadequate consent discussions are frequent allegations in the medico-legal cases seen at the CMPA. Studies support the intuitive notion that better patient-physician communication will lead to improved adherence, better long-term health outcomes, lower levels of medical mishaps, and reduced risk of medico-legal actions.2, 3

The consent discussion is about building a therapeutic relationship with the patient. The doctor's role is to give good advice – it is the patient's right to accept or reject that advice.

Good practice guidance

Reasonable patient standard

Walk in the shoes of your patient.

Patients can be their own best risk managers. If they have information on the reasons for a proposed investigation or treatment and are aware of the material and special risks, benefits, and alternatives, which may include not treating, they can participate in meaningful decisions about their own healthcare.

The adequacy of consent explanations is judged by the "reasonable patient" standard, that is, what a reasonable patient in the particular patient's position would have expected to hear before consenting.

In 1980, the Supreme Court of Canada ruled, in the landmark case of Reibl v. Hughes, that patients should be told what the doctor intends to do, as well as what the significant material risks are, and anything else that a reasonable person in that patient's condition would want to be told.

Landmark Canadian legal case - Reibl v. Hughes (1980) 2 SCR 880

When law and medicine intersect: a landmark Canadian legal case about consent to treatment.

Obtaining valid consent from patients has always involved explanations about the general nature of the proposed treatment and its anticipated effects. In the case of Reibl v. Hughes the Supreme Court of Canada established a more stringent standard: the adequacy of consent explanations is to be judged by the "reasonable patient" standard — what a reasonable patient in the particular patient's position would have expected to hear before consenting.

In the Reibl v. Hughes case the plaintiff had suffered a massive stroke during or immediately after an endarterectomy, which paralyzed the right side of his body. The trial judge found no negligence in the performance of the operation, but awarded compensation to the patient based on the allegation that the patient had not given his informed consent to the operation.

Legal considerations

The decision was upheld by the Supreme Court of Canada, which determined that the doctor had failed to adequately communicate to the patient the risk of stroke in connection with the operation. It was apparent to the court that had the doctor done so, a reasonable person in similar circumstances would not have opted for the surgery.

Why is this decision important?

This landmark decision impacts the day-to-day practices of physicians in Canada. The case clarified the doctrine of informed consent, which helps ensure that individuals have the freedom to make informed choices concerning their medical care.

Express and implied consent

  • In most cases, patient care is based on implied consent.
  • Express consent is one that is explicitly sought and given – either verbally or in writing.

Consent is often implied by either the words or the behaviour of the patient, for example by volunteering a history, answering questions, or submitting without objection to physical examination. When the examination is sensitive in nature, such as rectal, vaginal, or breast examinations, it is prudent to state the intention to examine the area in advance and obtain express consent.

When treatment may cause more than a little pain or carry significant risk, the patient should be asked to express their consent. A note in the patient's record may be adequate to document consent, but in some circumstances, it may be wise to obtain written consent.

3 key elements:

For consent to be considered valid:

  • it must be voluntary
  • the patient must have the capacity to consent
  • the patient must be properly informed

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  • Patients must be free to consent to or refuse treatment.
  • Consent should be obtained without duress or coercion. For example, patients brought into the emergency department by police for blood alcohol testing or on suspicion of trafficking drugs by ingestion, could reluctantly be following the course of action insisted on by the police. In these circumstances, physicians should satisfy themselves that the patient truly understands the implications of providing or not providing consent.
  • Where a patient is brought in by a third party to be examined, physicians should be more careful than usual to assure themselves the patient is in full agreement with what has been suggested. Avoid coercion (for example, by exaggerating the risks of consenting or of refusing) and determine that no one else has imposed their will on the patient. Having a private conversation with the patient to explore this issue specifically can be helpful.
    • If you are asked to perform a medical procedure to comply with a court order (for example a blood alcohol level) but the patient does not provide their consent to proceed, contact the CMPA for advice.
  • Patients may require additional time to weigh the information about the risks, benefits and alternative approaches in some circumstances. Ideally the patient would be provided information about the nature and risks of an investigation or procedure as early as possible in the referral process so that they may be afforded time to think about questions they may want answered.
    • Such circumstances might include consent for elective procedures, such as colonoscopy.
  • In some situations, one physician may have obtained informed consent for a procedure done by another (e.g. on-call procedures performed by a physician who covers a group practice). While this may streamline processes, it remains the responsibility of the physician who performs the treatment or investigation to ensure that informed consent was provided.
    • Even if the patient has already made the decision to undergo the procedure and has completed the required preparation, they are entitled to change their mind and to be given an opportunity to once again have a consent discussion about the risks and alternatives, to ask questions, and to confirm their choice prior to the procedure.

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A patient is considered to have the capacity to consent if he or she understands the:

  • nature of the proposed investigation or treatment
  • anticipated effects of the proposed treatment and alternatives
  • consequences of refusing treatment

Healthcare providers have a duty to take reasonable steps to be satisfied their patients have understood the appropriate information, particularly when there may be language difficulties, emotional issues, or questions of mental function. The ability of the patient to ask questions and the nature of those questions will often assist the physician to assess the level of the patient’s understanding.

It is important not to rely on yes or no answers to simple questions such as “Do you understand?”  Rather, engaging in dialogue with the patient will usually allow a physician to be reasonably confident that the patient appears to understand the explanation of consent.

One way to be reassured of the patient’s understanding is the teach-back technique: asking the patient to re-phrase what they have just been told and inviting them to ask questions. However, what constitutes "reasonable steps" to assess capacity will depend on the facts and circumstances of the particular situation.

With their permission and due consideration to the preservation of confidentiality, a physician may wish to encourage patients to invite a family member or friend to attend the discussion, as appropriate.

The Aid to Capacity Evaluation tool (ACE) may be helpful in assessing your patients’ capacity to consent.4

Landmark Canadian legal case – E. (Mrs.) v. Eve (1986) 2 S.C.R. 388

When law and medicine intersect: a landmark Canadian legal case about consent to treatment

The Supreme Court of Canada set limits on the non-therapeutic and therapeutic sterilization of mentally incapable (incompetent) patients.

In the 1960s, the mother of Eve petitioned the courts to allow the sterilization of her daughter, known by the pseudonym Eve. Eve was 24 years old and mildly to moderately intellectually disabled. She lived with her 60-year-old mother. Eve did not understand the "consequential relationship between intercourse, pregnancy and birth," and was considered incapable of providing consent to sterilization.

Eve lived much of the time at a special school, and there had been concern that she was developing a close relationship with a male student. Eve's mother feared Eve would at some point become sexually active and pregnant, with no one in the family able to assume responsibility and care for the child.

Legal considerations

The court declared that sterilization should not be authorized for mentally incapable (incompetent) persons for non-therapeutic purposes, such as for the purpose of contraception. It might be authorized in some circumstances for therapeutic purposes, such as the treatment of a disease.

The court stated that the integrity of a mentally incapable patient's body will generally take precedence over the desires of parents or substitute decision-makers, or the financial concerns of society. Sterilization for these patients without a sound medical indication infringes on that integrity. Patient autonomy must be the physician's overriding consideration in the context of non-therapeutic sterilization in these circumstances. The court stated: "In the absence of the affected person's consent, it can never be safely determined that [non-therapeutic sterilization] is for the benefit of that person."

Why is this decision important?

The court's decision has been interpreted by subsequent courts as prohibiting the ability of a parent or a substitute decision-maker to authorize the sterilization of a mentally incapable person for non-therapeutic reasons.

While the Eve decision was about the sterilization of a female, courts would likely apply the same principles when dealing with the sterilization (e.g. vasectomy) of a male who is not mentally capable.

Patients with mental illness

Individuals with mental illnesses, including those admitted to a psychiatric facility, are capable of controlling and directing their medical care if they understand:

  • what is proposed and why
  • the risks and alternatives
  • the potential consequences of their decision


The criterion for capacity to consent is maturity, not chronological age. A young person is considered capable of consenting or refusing treatment (i.e. a mature minor) if the physical, mental, and emotional development of the person will allow for a full appreciation of the nature and consequences of the decision.

There are two exceptions:

  • In Québec, the parent/guardian must consent if the child is under the age of 14.
  • In cases of requests for MAID, the patient must have reached the age of 18 years.

Generally, a capable minor needs to agree to the involvement of their parents in the decision-making process. Depending on the nature of the medical condition and the complexity of any proposed treatment, it is often prudent to stress to the patient the importance of involving his or her parents, and to obtain permission to do so.

When a minor is not capable of consenting, a parent or guardian provides consent and is required to act in the best interests of the child. If a parent/guardian refuses medically necessary treatment, a report to child protection authorities may be indicated, if the child is felt to be at risk of harm. CMPA members may consult the CMPA for advice should they be faced with such a complex situation.

Substitute decision-makers

Many jurisdictions have legislation governing procedures for obtaining consent from a substitute decision-maker (SDM) when a patient lacks capacity, such as through an advance directive or a hierarchal list of individuals who are authorized to act on behalf of the incapable person. If a patient is not capable of consenting, physicians should follow the procedure for obtaining consent that is governed by the applicable legislation in their jurisdiction.

An SDM can give valid consent only after receiving all the information that the patient would need before making a decision.

Sometimes it may be necessary to act when no SDM has been appointed. Practically speaking, it may be appropriate for physicians to proceed, based on the family's approval where medical treatment is clearly required and the patient’s condition may deteriorate if not treated promptly. Consulting another physician of calling the CMPA for advice may be wise if:

  • There is disagreement among family members.
  • The proposed treatment carries significant risks.
  • There are questions or doubts about what is in the patient's "best interest."
  • There is dispute over whether or not a proposed treatment is "therapeutic."

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Canadian legal judgments dealing with informed consent suggest the following interpretations about physician obligations around consent:

  • Inform the patient of the diagnosis, when possible. If some uncertainty exists about the diagnosis, mention this uncertainty, the reason for it, and what other possibilities you are considering.
  • Explain the proposed investigations or treatments.
  • Indicate the chances of success and/or anticipated outcome, covering both material and special risks.
  • Inform the patient about available alternative treatments and their risks. It is important not to neglect addressing the possibility of not treating and its associated risks. There is no obligation to discuss what might be clearly regarded as unconventional therapy, but patients should know there are other accepted alternatives and why the recommended therapy has been proposed.
  • Offer print material or electronic resources to support the consent discussion, but be mindful they are only an adjunct and do not replace the discussion.

The courts have been quite clear that physicians should answer patients' questions as honestly and completely as they can.

Material and special risks

  • Material risks include risks that occur frequently as well as those that are rare but very serious, such as death or permanent disability.
  • A patient's special circumstances might require discussion of potential but normally uncommon risks of the investigation or treatment. Special risks are those that are particularly relevant to the specific patient, when typically these might not be seen as material.
  • The courts have been clear that the consent discussion extends to what the physician knows or should reasonably know their patient would deem relevant to making a decision about whether or not to undergo treatment.

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Physicians are responsible for obtaining informed consent for the provision of virtual care, which includes discussing the limitations and benefits for the proposed virtual care modality. This discussion could include, but is not limited to:

  • a conversation about the technological and clinical limitations of virtual care
  • a review of alternatives to the proposed modality
  • an opportunity for the patient to ask questions

Physicians should consider reviewing the privacy risks associated with electronic communications in the informed consent discussion; they should also outline their efforts to mitigate these risks, including encouraging patients to participate in a private setting. Physicians can use this template [PDF] as a basis for the informed consent discussion relating to virtual care.

Physicians providing virtual care may want to advise patients that an in-person appointment may be necessary to complete the assessment. Physicians offering virtual care should familiarize themselves with standards and guidelines issued by their provincial or territorial regulatory authority (College) and any relevant privacy legislation.

The elements of informed consent described above (consent must be voluntary, the patient must have the capacity to consent, and the patient must be properly informed) remain unchanged regardless of whether consent is obtained virtually or in person. It is the physician’s responsibility to demonstrate that all elements of informed consent have been met. Documenting informed consent is an essential part of the informed consent process. Please refer to the section on Documentation of consent for details.

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The physician who performs the treatment or investigation is ultimately responsible for obtaining informed consent. She or he may delegate the duty, but should be confident the delegate has the knowledge and experience to provide adequate explanations to the patient and to answer the patient's questions. Although a trainee or other provider may generally know about the proposed investigation, procedure or medication, they should also know the special risks for the specific patient based on that patient’s medical condition. The delegate should alert the most responsible provider if they are uncertain as to what should be included in the consent discussion or the patient asks a question they cannot answer.

In situations of shared or group practices, it may be appropriate for one physician to have the informed consent discussion while another performs the procedure at a later date. In these circumstances, it is desirable that the physician who performs the treatment or investigation revisit the consent with the patient on the day of, and prior to, the procedure.

Where a part or all of the treatment is to be delegated to a trainee, patients have a right to know who will be involved in their care. Consent explanations should include such information.

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The consent discussion should be documented in the patient’s medical record. The note need not be long and can be general, but should be specific enough to clearly refer to the conversation that took place to obtain the patient’s consent.

To that end, the note might contain the following:

  • a mention of the discussion of material risks
  • specific special risks discussed
  • any questions the patient asked and answers given
  • consideration of the patient’s capacity to consent, as appropriate (e.g.  a mature minor or someone whose capacity might be questioned)
  • reference to copies of any handout materials provided to the patient

What is the purpose of a consent form?

In many Canadian jurisdictions, it is now a legal requirement that a consent form be completed before any surgical procedure is undertaken in a hospital. The consent form itself is only an acknowledgement that the patient agreed to what was proposed. It does not speak to the quality or substance of the consent discussion. Follow hospital requirements, if applicable, for completing a consent form, but pay special attention to capturing the content of the discussion as opposed to simply completing the form. Remember:

  • A consent form itself is not the patient’s consent.
  • The dialogue with the patient is the key element of the consent process.

In witnessing a signature, the witness simply confirms the identity of the patient who signed the document. The witness's role has no other legal significance.

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A physician may be liable in assault and battery for physically touching or treating a patient when no consent was given. Battery also includes treatment beyond, or deviating significantly from that for which consent was given. This is often relevant in surgical contexts, where a surgeon may choose to undertake an additional elective procedure that was not originally planned or for which consent was not provided (i.e. incidental removal of a healthy appendix during abdominopelvic surgery). Only when additional or alternative treatment is immediately necessary and vital to the health and life of the patient, should a physician proceed without express consent.

Surgeons may find it helpful to consider what other components of the surgery may arise, and to obtain express consent, prior to the surgery, for such potential situations and intraoperative decisions.

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In an emergency, if there is demonstrable severe suffering or an imminent threat to the life or health of the patient, and the patient or substitute decision-maker cannot consent, the physician may proceed to treat without consent. The physician has a duty to:

  • Do what is immediately necessary.
  • Respect any known previous wishes of the patient.
  • Obtain or confirm consent as soon as reasonably possible.

Document the circumstances why care was provided without consent from the patient or the substitute decision-maker.

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  • Courts have reaffirmed repeatedly a patient's right to refuse treatment even when it is clear that treatment is necessary to preserve the life or health of the patient and that their choice does not appear to be in their best interests.
  • While recognizing an individual's right to refuse, physicians must explain the consequences of the refusal without creating a perception of coercion.
  • Refusal of the recommended treatment does not necessarily constitute refusal for any treatment. When a patient refuses a proposed treatment, reasonable alternatives should be explained and offered to the patient.
  • Refusal of the recommended treatment at one point in time does not preclude revisiting the issue. Framing the issue as a “trial of non-intervention” and scheduling a follow-up visit may allow the patient to reconsider their choice at a later date. Exploring a person’s reasons for their choice may help identify other options for care.

One way to ensure that that your patients feel heard is to explore how they feel using the FIFE approach (ask about feelings, ideas, effects on function and expectations).

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Checklist: Informed consent

Patients must give valid consent before treatment or investigation

Consent must be given voluntarily, the patient must have capacity to consent, and the patient must be informed.

Have you:

  • Assessed the patient’s capacity to consent?
  • Ruled out any suggestion of duress or coercion (e.g. police requests for examination)?
  • Discussed the nature of the proposed treatment or investigation?
  • Presented the expected benefits and likelihood of success?
  • Identified the material risks? (frequent and/or serious/life threatening)
  • Identified the special risks? (rare but more likely or important to consider given the patient’s circumstances)
  • Discussed alternatives, including no therapy?
  • Considered supporting your consent discussion with print material or online resources?

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Have you:

  • Checked for patient understanding by asking them to teach back the discussion?
  • Explored the patient’s concerns and expectations?
  • Invited questions?
  • Used language tailored to the patient’s ability to understand?
  • Displayed empathy and respect for the patient’s choices?

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Have you:

  • Determined if the child is able to appreciate the nature and consequences of their decision? (or, in Québec, reached the age of 14)
  • Considered whether reporting the issue to child protection authorities is warranted if a parent/guardian refuses medically necessary treatment?
  • Considered involving parents/guardians, when appropriate and with the patient’s consent?

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Have you:

  • Discussed the limitations and benefits of virtual care?
  • Reviewed the privacy risks associated with electronic communications?
  • Advised the patient that an in-person appointment may be necessary to complete the assessment?
  • Ensured the patient’s consent meets the elements of informed consent as described in the sections on Obtaining a valid consent and Obtaining consent using a patient-centered approach?
  • Documented the informed consent process as described in the Documentation section?
  • Familiarized yourself with your provincial or territorial regulatory authority’s (College) virtual care policies and regulations?

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Have you:

  • Confirmed the patient’s consent in cases where the consent was obtained by a colleague?
  • Considered whether the medical trainee or health professional obtaining informed consent:
    • Has sufficient knowledge and experience of the investigation or therapy?
    • Knows the special risks for the specific patient?
    • Has informed the patient of their role, if they are a medical trainee?

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Have you:

  • Explained the consequences of refusing therapy without creating a perception of coercion?
  • Explained reasonable alternatives?
  • Sought to understand the patient’s perspective?
  • Considered the option of revisiting the issue at a follow-up appointment?

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Have you:

  • Obtained express consent when the physical examination is sensitive in nature, such as with rectal, vaginal, or breast examinations?
  • Avoided moving or removing patient’s clothing without express consent?
  • Avoided treatment beyond, or deviating significantly from, that for which consent was given?

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When there is no SDM and you are seeking the family’s consent have you:

  • Followed the procedure for obtaining consent that is governed by the applicable legislation in your jurisdiction?
  • Considered a medical or legal consultation?
    • if there is disagreement among family members.
    • the proposed treatment carries significant risks.
    • there are questions or doubts about what is in the patient's "best interest."
    • there is dispute over whether or not a proposed treatment is "therapeutic."

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In an emergency, if there is demonstrable severe suffering or an imminent threat to the life or health of the patient, and the patient or substitute decision-maker cannot consent;

Have you:

  • Done what is immediately necessary?
  • Respected any known previous wishes of the patient?
  • Obtained or confirmed consent as soon as reasonably possible?
  • Documented the circumstances why care was provided without consent from the patient or the substitute decision-maker?

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Have you:

  • Written a note that refers to your consent discussion?
  • Documented the material and special risks discussed?
  • Noted any questions asked by the patient and answers given?
  • Secured a signed consent form if required by hospital policy?
  • Noted the use of any print or online material used to support the informed consent and kept a copy on file?

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  1. Schloendorff v. Society of New York Hospital (1914), 211 N.Y. 125, 105 N.E. 92
  2. Stiggelbout AM, Van der Weijden T, De Wit MPT, et al. Shared decision making: really putting patients at the centre of healthcare. BMJ 2012; 344:e256. DOI: https://doi.org/10.1136/bmj.e256  Available from: https://www.bmj.com/content/344/bmj.e256.full
  3. Braddock CH, Fihn SD, Levinson W, et al. How Doctors and Patients Discuss Routine Clinical Decisions, Informed Decision Making in the Outpatient Setting. J Gen Intern Med 1997; 12:339-345. Available from: https://onlinelibrary.wiley.com/doi/epdf/10.1046/j.1525-1497.1997.00057.x;
  4. University of Toronto, Joint Centre for Bioethics. Aid to Capacity Evaluation (ACE).  Available from: http://www.jcb.utoronto.ca/tools/ace_download.shtml
CanMEDS: Communicator

DISCLAIMER: The information contained in this learning material is for general educational purposes only and is not intended to provide specific professional medical or legal advice, nor to constitute a "standard of care" for Canadian healthcare professionals. The use of CMPA learning resources is subject to the foregoing as well as the CMPA's Terms of Use.