A patient is presumed to have decision-making capacity unless proved otherwise. In medical settings it is the physician's responsibility to determine it.
Capacity may change depending on the patient's condition and the complexity of the decision; he/she needs to be able to
- understand relevant information and the implications of treatment choices
- reflect in accordance with personal values and draw conclusions
- make and communicate a choice to healthcare professionals
In clinical settings, physicians should first assess the patient's mental status and then, if necessary, look for treatable physical conditions that may be interfering his/her ability to process information and draw conclusions.
- can be temporarily compromised by delirium, dementia, metabolic imbalances, severe pain, and life-threatening infections
- may fluctuate hour by hour because of drugs to control symptoms
- shifts in levels of consciousness caused by advancing disease, and psychological factors such as the patient's denial of serious illness
Jaffe E and Knight CF. Unipac six: ethical and legal dimensions of treating life-limiting illness. Hospice and palliative care training for physicians: a self-study program. American Academy of Hospice and Palliative Medicine. Third edition. 2008. Page 15.