Autonomous decision making by patients can be enhanced by a variety of advance directives. These directives, the living will and the durable power of attorney, have an ethical and legal basis on which the patient can prospectively make decisions about life-sustaining therapies. The strength of these directives can be enhanced by the use of the Values History, serving as an adjunct to them. The Values History can also be used as a clinical tool to elicit the values of the patient as they pertain to chronic as well as critical medical care. Documentation of the patient's values will give the health care team a fuller understanding of the patient's preferences and directions.