In the best of circumstances, the patient, the family, and the physician have held discussions about treatment options, including the length and invasiveness of treatment, chance of success, overall prognosis, and the patient’s quality of life during and after the treatment. Ideally, these discussions would continue as the patient’s condition changed. Frequently, however, such discussions are not held. If the patient becomes incapacitated due to illness, the patient’s family and physician must make decisions based on what they think the patient would want.