Assessing competency in the elderly.

The doctrine of informed consent requires that a patient understand the medical procedure being proposed, that consent be voluntary, and that the patient be competent to give consent. Because of declining cognitive functioning, elderly patients are at significant risk of becoming incompetent and, therefore, unable in the eyes of the law to give informed consent. Advance directives allow competent patients to tell their doctors and the world in general what their health care choices are should they not be able to make their choices clear in the future. The living will and durable power of attorney are two types of advance directives that are legally binding in most states.