Capacity

Capacity is a medical judgment regarding the ability to make decisions about health-related matters. An older person faced with a health care decision is presumed capable of making that decision unless or until proven otherwise.

Capacity may come into question if an older person exhibits memory problems or has difficulty thinking clearly. In such a case, doctors may be asked to evaluate the person's capacity. Doctors determine whether the person understands the condition of his health and the good and harm that might come from each decision he is asked to make. They also determine if the person can weigh the consequences of treatment or a refusal of treatment against personal preferences and values. Doctors are more confident in a person's capacity to make decisions if the person has a consistent pattern of choices over time that reflect values that have been discussed with others.

Ideally, doctors apply the results of the evaluation only to the specific matter at hand. A person who experiences difficulty making choices in one situation may not experience difficulty in every situation. Capacity is decision-specific, and some decisions are far more complex than others.

When an older person already has some loss of mental function, a sudden illness may further undercut his ability to make decisions about health-related matters. This abrupt decrease in capacity often happens during a hospitalization, when the change in surroundings and daily routine adds to any confusion caused by the illness. If the person becomes incapacitated, health care practitioners must rely on family members, unless the incapacitated person has made his wishes known before becoming incapacitated. If the person has no family (or, in some cases, even if the person does), the local court can appoint someone to make decisions.