Questions About the Substitute Decision Maker

What if More than One Person is Entitled to Act as my Substitute Decision Maker?

If there is more than one person in your life at one level in the hierarchy and they are the highest ranked highest in the hierarchy, they must make decisions together (jointly) or decide among themselves which one will act as your substitute decision maker.

For example, if you have three children (#5 on the hierarchy), all three are entitled to act as your substitute decision maker. They must act together and agree on any decisions for your health care. If they agree that only one of them should make decisions for you, then that one child may make decisions for you. The health professionals cannot pick which one of the three should make decisions for you. The three children must decide among themselves whether they all act together or which one of them will act.

If there is a conflict among people who are equally entitled to act as your SDM and they cannot agree on the decisions about your treatment, the Public Guardian and Trustee is required to act as your substitute decision maker. The Public Guardian and Trustee does not choose between the disagreeing decision makers but makes the decision instead.

What Kinds of Decisions do SDMs Make?

Decisions include:

  • consenting to tests, surgery, procedures or other medical care
  • starting or refusing treatment or withdrawing life prolonging measures
  • admission or discharge from a medical facility
  • moving into or receiving personal care in a long-term care home.

These decisions should be based on your previously expressed wishes, values and beliefs.

How do SDMs Make Decisions?

When your substitute decision maker has to step in and make decisions for you, he or she is required to honour and apply the wishes, values and beliefs that you communicated when you were still mentally capable.

If your wishes are not known, your SDM is required to act in your “best interests”. “Best interests” has a specific meaning in law. It involves your SDM considering the values and beliefs you had when capable. In addition, the SDM would consider:

  • your health condition;
  • if you were likely to improve, remain the same or deteriorate without the treatment;
  • the risks and benefits of the treatment options.

SDMs do not have to follow a wish that is impossible to honour. For example, you may communicate to your future SDM that you want to receive treatment in your home and not a hospital. These types of wishes may be impossible to honour depending on many factors, including your actual state of health, your care needs, the availability of public or private home care, financial resources and the availability of family and others to help care for you in your own home.

What Else is Important to Consider about your SDM?

Your SDM should be someone who you feel would understand and honour your wishes: someone who would be able to make health or personal care decisions on your behalf.


  • Do I trust this person(s) to make decisions that reflect my wishes even if they disagree with them?
  • Can they make decisions under stress?
  • Can I engage the person(s) in conversations about my wishes, values and beliefs as they relate to future health or personal care?
  • Can they communicate clearly with my health team in a stressful situation?
  • Is this person willing and available to speak for me if I cannot speak for myself?