n. agreement to undergo any medical treatment or to participate in medical research. There are four criteria that must be met for consent to be legally valid, namely: (i) the patient must have capacity to make a choice; (ii) the patient must be provided with sufficient information (see informed consent) as to the nature of treatment, its likely consequences, and the possible effects of not having treatment; (iii) the patient must be in a position to decide voluntarily, i.e. without external pressure or influence, which may entail giving the patient time to consider the options; and (iv) the patient should be largely consistent in their views and understand that they can change their mind about treatment at any point. Valid consent usually provides a legal defence against the charge of battery (trespass against the person). Claims of negligence may be brought if the doctor discloses insufficient or inadequate information or fails to answer the patient’s questions and address his or her concerns.
The law requires consent to be evidenced in writing only in special cases, such as recruiting a subject to a clinical trial. However, consent forms are commonly used for evidential purposes and to communicate a patient’s choice within the health-care team. Valid consent is not required in an emergency or where a patient lacks capacity. It used to be that the concept of therapeutic privilege provided a further exception to the requirement that patients should give valid consent, but such a position is contentious and considered by many commentators to be outdated and inappropriate. See also assent, autonomy.
Subjects: Medicine and Health — Law.