Consent guidance: Legal Annex - Common Law


Chester v Afshar [2004] UKHL 41 Pt 2
The duty to warn patients about risk

Ms Carole Chester was left partially paralysed after surgery for lumbar disc protrusion. Dr Afshar had failed to warn Ms Chester that this was a foreseeable (1–2%) but unavoidable risk of the surgery. The House of Lords concluded that, though the failure to warn was not a direct cause of injury, it did result in negligence. In particular, Lord Bingham stated [para 16]:

A surgeon owes a general duty to a patient to warn him or her in general terms of possible serious risks involved in the procedure. The only qualification is that there may be wholly exceptional cases where objectively in the best interests of the patient the surgeon may be excused from giving a warning…In modern law medical paternalism no longer rules and a patient has a prima facie right to be informed by a surgeon of a small, but well-established, risk of serious injury as a result of surgery.

  • Patients should be told of any possible significant adverse outcomes of a proposed treatment.
  • In this case, a small but well-established risk of a serious adverse outcome was considered by the House of Lords to be ‘significant’.

Refusal of treatment

Re C (Adult, refusal of treatment) [1994] 1 All ER 819

The right of a competent adult to refuse medical treatment/The principle that mental illness does not automatically call a patient’s capacity into question.


C had paranoid schizophrenia and was detained in Broadmoor secure hospital. He developed gangrene in his leg but refused to agree to an amputation, which doctors considered was necessary to save his life. The Court upheld C’s decision.

  • The fact that a person has a mental illness does not automatically mean they lack capacity to make a decision about medical treatment.
  • Patients who have capacity (that is, who can understand, believe, retain and weigh the necessary information) can make their own decisions to refuse treatment, even if those decisions appear irrational to the doctor or may place the patient’s health or their life at risk.

Re MB (Adult, medical treatment) [1997] 38 BMLR 175 CA

Capacity to refuse treatment


MB needed a caesarean section, but panicked and withdrew consent at the last moment because of her needle phobia. The hospital obtained a judicial declaration that it would be lawful to carry out the procedure, a decision that MB appealed. However, she subsequently agreed to induction of anaesthesia and her baby was born by caesarean section.

The Court of Appeal upheld the judges' view that MB had not, at the time, been competent to refuse treatment, taking the view that her fear and panic had impaired her capacity to take in the information she was given about her condition and the proposed treatment. In assessing the case the judges reaffirmed the test of capacity set out in the Re C judgement.

  • An individual’s capacity to make particular decisions may fluctuate or be temporarily affected by factors such as pain, fear, confusion or the effects of medication.
  • Assessment of capacity must be time and decision-specific.

Re B (Adult, refusal of medical treatment) [2002] 2 All ER 449

Right of a patient who has capacity to refuse life-prolonging treatment


B was a 43-year-old woman who had become tetraplegic and who no longer wished to be kept alive by means of artificial ventilation. She asked for ventilation to be withdrawn but the doctors caring for her were unwilling to agree to this. B, whose mental capacity was unimpaired by her illness, sought and obtained a declaration from the court that the hospital was acting unlawfully.

  • A competent patient has the right to refuse treatment and their refusal must be respected, even if it will result in their death.

St George's Healthcare NHS Trust v S; R v Collins and others, ex parte S [1998] 3 All ER 673

The right of a competent pregnant woman to refuse treatment even if that refusal may result in harm to her or her unborn child/Application of the Mental Health Act 1983.


S was diagnosed with pre-eclampsia requiring admission to hospital and induction of labour, but refused treatment because she did not agree with medical intervention in pregnancy. Although competent and not suffering from a serious mental illness, S was detained for assessment under the Mental Health Act. A judge made a declaration overriding the need for her consent to treatment, and her baby was delivered by caesarean section.

The Appeal Court held that S’s right to autonomy had been violated, her detention had been unlawful (since it had been motivated not by her mental state but by the need to treat her pre-eclampsia) and that the judicial authority for the caesarean had been based on false and incomplete information.

  • A competent pregnant woman can refuse treatment even if that refusal may result in harm to her or her unborn child.
  • Patients cannot lawfully be detained and compulsorily treated for a physical condition under the terms of the Mental Health Act.

Re T (Adult) [1992] 4 All ER 649
The effect of coercion/pressure on patient consent

T, a 20-year-old pregnant woman, was injured in a car accident and developed complications that required blood transfusions. She did not indicate on admission that she was opposed to receiving transfusions but after spending some time with her mother, who was a practising Jehovah's Witness, she decided to refuse the treatment.

The Court of Appeal considered that T had been pressurised by her mother and that her ability to decide about the transfusions was further impaired by the drugs with which she was being treated. The Court allowed the blood transfusions to proceed.

  • A patient’s consent to a particular treatment may not be valid if it is given under pressure or duress exerted by another person.

Requests for treatment

Mr Leslie Burke v GMC [2005] EWCA Civ 1003

This case concerned a wide range of issues, most of which related to decision-making at the end of life. However, for the purposes of this guidance, the key point is the Court of Appeal’s opinion that doctors are under no legal or ethical obligation to agree to a patient’s request for treatment if they consider the treatment is not in the patient’s best interests.

Children and young people

Gillick v West Norfolk and Wisbech AHA [1986] AC 112

Children and young people’s competence to consent to treatment


Mrs Gillick challenged the lawfulness of Department of Health guidance that doctors could provide contraceptive advice and treatment to girls under the age of 16 without parental consent or knowledge in some circumstances.

The House of Lords held that a doctor could give contraceptive advice and treatment to a young person under the age of 16 if:

  • she had sufficient maturity and intelligence to understand the nature and implications of the proposed treatment
  • she could not be persuaded to tell her parents or to allow her doctor to tell them
  • she was very likely to begin or continue having sexual intercourse with or without contraceptive treatment
  • her physical or mental health were likely to suffer unless she received the advice or treatment
  • the advice or treatment was in the young person’s best interests.

This case was specifically about contraceptive advice and treatment, but the case of Axon, R (on the application of) v Secretary of State for Health [2006] EWHC 37 (Admin) makes clear that the principles apply to decisions about treatment and care for sexually transmitted infections and abortion, too.

  • As a result of this decision, a young person under 16 with capacity to make any relevant decision is often referred to as being ‘Gillick competent’.

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