[On a principal of advance directives].

We explored a principle of advance directives. Advanced directives are a tool to help execute a broader concept of advance care planning, which is included in advance life planning. Advance directives should be formed by consent with inter- and multi-disciplinary care teams on the basis of patient's intension, passing process such as medical treatment, patient care and mental supports. The contents can update according to patient's health condition and environment. A definition of advance directives is, "oral or written statement in which people declare their treatment preferences in the event that they lose decision-making capacity". Under the present conditions in Japan, we show two problems that the process which reaches to the consent formation is neglected, and the document preparation is excessively considered. Advance directives are of two principle types: instructional directives and proxy consent. There are advantages and disadvantages to each type, and people often used a combination of both types. We conclude an interpretation process of instructional directive with proxy (key person), which assumes the patient's intention, is important for advance directives.