Intended for healthcare professionals


UK law on consent finally embraces the prudent patient standard

BMJ 2015; 350 doi: (Published 28 May 2015) Cite this as: BMJ 2015;350:h2877
  1. Leroy C Edozien , consultant obstetrician and gynaecologist
  1. 1Manchester Academic Health Science Centre, University of Manchester, St Mary’s Hospital, Manchester M13 9WL, UK
  1. leroy.edozien{at}

But it will take much more to change clinical practice

The UK Supreme Court’s decision in the Montgomery case is a landmark judgment, establishing beyond doubt the court’s commitment to protecting patients’ right to self determination. 1 The judgment concerns Nadine Montgomery, a woman with diabetes whose son was born with serious and permanent disabilities after a shoulder dystocia during delivery. Montgomery’s obstetrician had not warned her of the risk of shoulder dystocia during vaginal delivery or discussed alternatives such as caesarean section. The court held that the doctor should have done both: doctors have a duty to ensure that each patient is aware of any material risks of any recommended treatment and of any reasonable alternative treatments. The test of materiality is whether a reasonable person in that particular patient’s position would be likely to attach importance to the risk, or whether the doctor is—or should reasonably be—aware that that particular patient would be likely to attach importance to it. The message for clinicians is: know your patient and provide tailored information.

The patient must be given sufficient information, but what constitutes sufficient? Two standards of disclosure have been employed: the professional standard (the court relies on medical opinion) and the “prudent patient” standard (the court considers what a reasonable person would want to know to make an informed choice).

Doctrine of informed consent

The requirement for full disclosure of material risks to the patient, with the standard of disclosure being determined not by the medical profession but by the court, is known as the legal doctrine of informed consent. This doctrine is well established in many US jurisdictions, Canada, and Australia, but the courts resisted its incursion into the UK for decades. The definitive UK position (before the Montgomery case) on this doctrine was established by the House of Lords in the case of Sidaway. 2 The court ruled that the doctrine of informed consent did not apply in the UK and endorsed the position articulated in the case of Bolam that: “a doctor is not guilty of negligence if he has acted in accordance with a practice accepted as proper by a responsible body of medical men.”3

Departure from the professional standard

The courts do, however, move with the times, and there has been a gradual but steady shift away from the professional standard. The case of Bolitho established that if professional opinion does not withstand logical analysis the judge is entitled to hold that the body of opinion is not reasonable or responsible.4 In the case of Pearce the Court of Appeal stated that “a doctor’s decision not to disclose risks will now have to be subjected to logical analysis,” and if he has withheld information without good reason “he will be liable even though his decision may have been consonant with ordinary professional practice.”5 More recently, in the Chester case the House of Lords side stepped the traditional requirement to prove causation (that is, had the claimant been warned of the undisclosed risk, she would not have had the treatment) in order to protect the patient’s right to self determination.6 And in the case of Birch, the High Court stated that the duty to disclose significant risks included information about alternative treatments.7 The Montgomery case thus marks the final stage of the UK courts’ transition from the professional standard to the prudent patient standard.

Potential effect (or lack of it) on clinical practice

While this is a landmark judgment, its effect on clinical practice could be limited unless a concerted effort is made to reconceptualise consent on the shop floor. Current professional guidance on consent already approximates to the prudent patient standard, advising doctors to provide information that the patient would want to be given.8 9 10 11 The position of the Supreme Court on the importance of dialogue in consent transactions, the need to ensure that the patient understands the information provided, and the therapeutic privilege (whereby a doctor may withhold information from a patient if disclosing it would cause serious psychological harm) is consonant with published professional guidance.

However, the model of consent that is applied in actual practice (contrived consent) differs from that described in professional guidance (bona fide consent). Bona fide consent is where the patient makes an informed choice after a dialogue with the doctor, in a collaborative relationship. In contrived consent, the patient is presented with a menu of choices and a response is elicited. The menu may be accompanied by a large quantity of information, most of it not specific to the patient, or little or no information. The emphasis is not on the patient’s understanding of information but on his or her signal that the doctor may proceed with treatment. In most consultations the signal is verbal, but for surgery it is usually a signature.

The current model relies heavily on consent forms. But many clinicians are unaware that consent can be valid without a signed consent form (it is the patient’s informed choice that constitutes consent, not the form), while consent can be invalid even though a consent form has been signed (because the patient has not made a self determining, informed choice).

Contrived consent has prevailed despite the abundance of legal, ethical, and professional guidance on bona fide consent, because of deficiencies in doctors’ and patients’ perceptions of consent. Health professionals do not know enough about the law of consent, and patients see the consent process not as a means to protect their rights but as a means of protecting the doctor from litigation.12 13 Medical professionalism demands that the gap between the ideal and the operationalised methods of consent should be closed. Medical schools, royal postgraduate medical colleges, and service quality regulators must take up this difficult challenge.


Cite this as: BMJ 2015;350:h2877


  • Competing interests: I have read and understood BMJ policy on declaration of interests and declare I am the author of the book Self-determination in Health Care: A Property Approach to the Protection of Patients’ Rights.

  • Provenance and peer review: Not commissioned, externally peer reviewed.


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