What is a substitute decision maker?
A substitute decision maker is a person legally authorized to make health care decisions on behalf of someone who lacks the capacity to make those decisions themselves, as defined under Ontario's Health Care Consent Act.
Under Ontario's Health Care Consent Act, a substitute decision maker is someone appointed or designated to make health care decisions for a person who cannot make those decisions themselves. This person steps in when a senior or other individual loses decision-making capacity due to illness, injury, cognitive decline, or other circumstances.
Substitute decision makers operate in a clear hierarchy set out by the act. A person may designate a substitute decision maker through a power of attorney for personal care while they still have capacity. If no advance directive exists, the act establishes a priority order: a court-appointed guardian, a power of attorney holder, a representative appointed by the Consent and Capacity Board, and then family members or close friends in a specified sequence.
Their role includes consenting to, refusing, or withdrawing consent from medical treatment, admission to care facilities, or other health interventions. They must act in the best interests of the person they represent and, where possible, follow any instructions the person expressed before losing capacity. This responsibility matters significantly in aged care settings across London, Ontario, where aged care providers regularly work with substitute decision makers to obtain proper authorization for care plans, medications, and placement decisions.
A substitute decision maker must make decisions based on the person's values, preferences, and expressed wishes, not on what the decision maker prefers. If disputes arise about whether someone has capacity or whether a substitute decision maker is acting appropriately, the matter may go to the Consent and Capacity Board for review.