How to determine decisional capacity in critically ill patients. Presume the patient can make decisions unless proven otherwise.

Decisional capacity includes ability to comprehend information, to make an informed choice, and to communicate that choice; it is specific to the decision at hand. Presume a patient has decisional capacity; an evaluation of incapacity must be justified. Administer a standardized mental status test to help assess alertness, attention, memory, and reasoning ability. A patient scoring below 10 on the Folstein Mini-Mental State Examination (maximum score, 30) probably does not have decisional capacity; one scoring from 10 to 15 probably can designate a proxy but not make complex health care decisions. Obtain psychiatric consultations for a patient who exhibits psychological barriers to decision making.