This act recognizes the right of a patient to control decisions relating to his or her medical care and to execute a written direction regarding life-sustaining procedures. Under the  law, an individual of sound mind who is 18 years of age or older (or who has graduated from high school or married) may execute a declaration governing the initiation, continuation, withholding, or withdrawal of “life-sustaining treatment.” The declaration must be signed by the declarant (or by another person at the request of the declarant if the declarant is unable to sign) and must be witnessed by two individuals over the age of 18. The declaration may include a designation of another person (a “surrogate”) to make treatment decisions for the declarant if the declarant later becomes incompetent.