Medical Treatment: Decisions and the Law

1. Consent – General


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; 1 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.

This chapter addresses those cases in which consent is or should be obtained. 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.


  • A Framework  1.1
  • Introduction 1.1
  • Proposal to treat  1.3
    • Formulation of proposal  1.3
    • Risks of treatment  1.4
    • Alternative forms of treatment 1.5
    • Compelling a doctor to treat  1.6
    • Irrational decisions by care providers to refuse treatment 1.7
    • Resources  1.8
    • Treatment demanded by the patient 1.9
  • Communication of the proposal  1.10
  • Consent – state of mind  1.13
    • Intention  1.13
    • Comprehension 1.14
  • Communication of consent 1.15
    • Written consent 1.16
    • Oral consent  1.17
    • Conduct  1.18
  • Information about risks  1.19
  • No doctrine of informed consent in relation to trespass to the person 1.19
  • Duty of care – common law position  1.20
  • The test of materiality  1.21
  • Duration of the duty to advise on all material risks 1.22
  • Article 8  1.23
  • Delegation  1.24
  • Duty to answer questions  1.25
  • Information about alternative forms of treatment 1.27
  • Known comparative outcomes 1.28
  • Vitiating factors 1.30
  • Fraud  1.31
  • Duress and undue influence 1.32
  • Capacity  1.33
  • Scope of authority  1.34
  • Duration of authority  1.35
  • Withdrawal of authority 1.37
  • Conclusion  1.38
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