What Is a Substitute Decision Maker (SMD)?

A substitute decision maker (SDM) is a person chosen by an individual to make health care decisions on their behalf in the event they become unable or incompetent to make their own health care decisions. This may occur due to a serious injury or illness. The SDM is typically identified prior to making any major health declarations. An SDM may be referred to as an alternate decision maker, or as a health care representative, agent or proxy.

Information from an individual’s advance directive, personal directive, living will, or what is personally known about the individual is used to make informed health care determinations. Decisions made by an SDM may include consent or refusal of treatments, medications or procedures.

An SDM should be trusted and willing to make difficult decisions. They should also be someone the individual has had conversations with concerning desires, values and preferences. The process for appointing an SDM may vary per country, state, province or territory. It typically involves creating and signing a representation agreement or a personal or proxy directive. Individuals should speak with their physician and attorney about designating a local SDM.

In certain cases, if an SDM is needed but has not yet been selected, they may be appointed by a court of law. An SDM may also be a “default surrogate,” which can include spouses, adult children, parents, or other close relatives. When necessary, a physician or group of physicians, social workers, or hospital ethics committee can also be appointed as decision makers.