Can the patient decide? Evaluating patient capacity in practice.

Physicians assess the decision-making capacity of their patients at every clinical encounter. Patients with an abrupt change in mental status, who refuse recommended treatment, who consent too hastily to treatment or who have a known risk factor for impaired decision-making should be evaluated more carefully. In addition to performing a mental status examination (along with a physical examination and laboratory evaluation, if needed), four specific abilities should be assessed: the ability to understand information about treatment; the ability to appreciate how that information applies to their situation; the ability to reason with that information; and the ability to make a choice and express it. By using a directed clinical interview or a formal capacity assessment tool, primary care physicians are able to perform these evaluations in most cases.