The legality of all medical treatment is founded on the existence of consent or some other lawful authority. The general principle is that no form of medical treatment can be given without either the consent of the capable patient, or, if the patient is a child or an incapable adult, either the consent of someone with the authority to give consent on the patient ’ s behalf or the authority of the court*; or, if the patient is incompetent and aged over 16, by reason of the common law doctrine of necessity (as applied within the statutory regime of the Mental Capacity Act 2005 (‘ MCA ’). The very structure of the last sentence reflects the convoluted nature of the law in this area, which is a result of its piecemeal, largely accidental development.
Although the provision of medical treatment and consent to it may form a legal contract, it need not do so. The process, however, is similar: there must be a proposal to treat (or ‘ offer ’ in contractual parlance); a communication of that proposal or offer; understanding of what is proposed; consent to or acceptance of it; and communication of the consent or acceptance by a patient possessing the relevant capacity. The ingredients necessary for a contract which will often be missing in the context of the National Health Service will be consideration for the offer of treatment, and intention to form legal relations in the contractual sense.
*If the patient is a child, the court can consent on their behalf; if the patient is an incompetent adult, a court can declare that proposed treatment would be lawful, being in their best interests.
This article is adapted from Medical Treatment: Decisions and the Law, Third Edition written by members of Serjeants' Inn Chambers, and edited by Christopher Johnston QC. This title is also available as part of a subscription on Bloomsbury Law Online.