An advance directive is a legal document that protects the medical decisions of a dying person who is unable to communicate a decision at the time of care delivery. It is made up of two elements: (1) a living will, a document describing the care a person would or would not want under certain circumstances, and (2) a durable power of attorney for health care—that is, a surrogate appointed to make medical decisions on behalf of an incapacitated person. (Addressed in a separate entry, do-not-resuscitate [DNR] orders are a subtype of living will that pertain only to stoppage of breathing or heartbeat.)

Advance directives are important to consider in the study of lifespan human development because advances in medical technology have made most deaths predictable, plannable ...