Refers to the ability of a patient to make a rational choice in his or her own best interest. A person may be diagnosed as mentally incapacitated if he or she cannot make a decision on a matter in question, or if they cannot communicate a decision because they are unconscious. That is, the patient needs to understand the question in its context, the nature of the decision he or she is being asked to answer, and the implications of the answer.
Refers to the ability of a patient to make a rational choice in his or her own best interest. A person may be diagnosed as mentally incapacitated if he or she cannot make a decision on a matter in question, or if they cannot communicate a decision because they are unconscious. That is, the patient needs to understand the question in its context, the nature of the decision he or she is being asked to answer, and the implications of the answer.
In this regard, decisional capacity is the ability to understand information relevant to a decision and to appreciate the reasonably foreseeable consequences of a decision or lack of decision. Capacity is specific to particular decisions: a person may be capable with respect to deciding about a place of residence, for example, but incapable with respect to deciding about a treatment. In addition, capacity can change over time, in that, a person may be temporarily incapable because of delirium but subsequently recover his or her capacity.
The ethical principles of patient autonomy and respect for persons require that capable people be allowed to make their own informed decisions. However, the ethical principle of physician beneficence requires that incapable people be protected from making decisions that are harmful or that they would not make if they were capable.
The relevant areas of patient capacity specified in the Aid to Capacity Assessment (a commonly used tool to determine decisional capacity) include:
- Ability to understand the medical problem.
- Ability to understand the proposed treatment.
- Ability to understand the alternatives (if any) to the proposed treatment.
- Ability to understand the option of refusing treatment or of it being withheld or withdrawn.
- Ability to appreciate the reasonably foreseeable consequences of accepting the proposed treatment.
- Ability to appreciate the reasonably foreseeable consequences of refusing the proposed treatment.
- Ability to make a decision that is not substantially based on delusions or depression.
Also see
Canadian Medical Association Journal, Bioethics for clinicians