Competent children can consent to treatment but cannot refuse treatment. The consent of one parent is sufficient if the other one disagrees. Parental choice takes precedence over the child’s choice. The courts can overrule parents. Life-saving treatment of minors is given even if parents refuse. Parental choice is final in therapeutic or non-therapeutic research on children.

Mental patients

Mental patients cannot consent to treatment, research, or sterilization because of their intellectual incompetence. They are admitted, detained, and treated voluntarily or involuntarily for their own benefit, in emergencies, for purposes of assessment, if they are a danger to themselves, or on a court order. Suicidal patients tend to refuse treatment because they want to die.

The unconscious

For patients in coma, proxy consent by family members can be resorted to. If no family members are available, the physician does what he as a professional thinks is in the best interest of the patient.

There are many disputes about withdrawing nutrition, hydration, and treatment in a persistent vegetative state since the chance of recovery is low. There is no moral difference between withholding and withdrawing futile treatment.

Obstetrics

Labor and delivery are emergencies that require immediate decisions but the woman may not be competent and proxies are used. Forced medical intervention and cesarean section may be ordered in the fetal interest. Birth plans can be treated as an advance directive.