Montgomery v Lanarkshire Health Board

A doctor advising an adult patient of sound mind must take reasonable care to ensure that the patient knows the material risks of recommended treatment and any reasonable alternatives. A risk is material if a reasonable person in the patient’s position would probably regard it as significant, or the doctor knows or ought to know that the particular patient would do so.

Disclosure is a legal duty founded on patient autonomy. It is not governed by the professional-practice test applicable to diagnosis and treatment. Materiality is fact-sensitive and cannot be determined by percentages alone.

Any therapeutic exception is narrow. It cannot justify withholding information merely because the doctor believes that the patient may choose an option contrary to her best interests.

Mrs Montgomery, an insulin-dependent diabetic of small stature, had a 9–10% risk of shoulder dystocia during vaginal delivery. Her consultant did not disclose that risk or discuss elective caesarean section because she believed that the small risk of grave injury did not justify disclosure and that disclosure would lead most diabetic women to request caesarean delivery.

Shoulder dystocia occurred. The child suffered cerebral palsy and a brachial plexus injury. An elective caesarean section would have avoided those injuries.

The Lord Ordinary rejected the negligence claim in [2010] CSOH 104, applying the professional-practice approach associated with Sidaway v Board of Governors of the Bethlem Royal Hospital and the Maudsley Hospital. The Inner House upheld that decision in [2013] CSIH 3; 2013 SC 245. The central issues before the Supreme Court were the scope of a doctor’s duty to disclose treatment risks and alternatives, and whether proper disclosure would probably have led Mrs Montgomery to choose caesarean delivery.

1. Disposition. The Supreme Court unanimously allowed the appeal. Lord Kerr and Lord Reed delivered the joint judgment, with which Lord Neuberger, Lord Clarke, Lord Wilson and Lord Hodge agreed. Lady Hale delivered additional observations and agreed entirely with the joint judgment.

2. A doctor’s advisory role is distinct from the exercise of professional skill in diagnosis and treatment. Whether patients should be told about treatment risks and reasonable alternatives is governed by their entitlement to decide which risks to accept. It is a question of law rather than a matter determined by responsible medical practice. The majority analysis in Sidaway v Board of Governors of the Bethlem Royal Hospital and the Maudsley Hospital [1985] AC 871 was rejected insofar as it placed advice about risks within the Bolam test. The approach of Lord Scarman in that case, and of Lord Woolf MR in Pearce v United Bristol Healthcare NHS Trust [1999] PIQR P 53, was substantially adopted.

3. An adult patient of sound mind is entitled to decide which available treatment, if any, to undergo. The doctor must take reasonable care to ensure that the patient knows any material risks involved in recommended treatment and any reasonable alternative or variant treatments. A risk is material where either a reasonable person in the patient’s position would probably attach significance to it, or the doctor knows or ought reasonably to know that the particular patient would probably do so.

   Materiality cannot be reduced to percentages. Relevant matters include the nature and magnitude of the risk, its effect on the patient’s life, the expected benefits, the available alternatives, their risks, and the particular patient’s characteristics and concerns. The advisory process requires comprehensible dialogue rather than technical information or routine reliance on a signed consent form.

4. A doctor may respect a patient’s clear wish not to receive risk information. Information may also be withheld where disclosure would, in the reasonable exercise of medical judgment, be seriously detrimental to the patient’s health, or where urgent necessity prevents consultation. The therapeutic exception is narrow. It cannot be used to prevent an informed choice merely because the doctor considers that choice contrary to the patient’s best interests.

5. The 9–10% risk of shoulder dystocia was material. It involved a major obstetric emergency, potentially traumatic procedures and risks to both mother and child. The availability and comparatively low risks of elective caesarean section strengthened the need for disclosure. The consultant also knew that Mrs Montgomery was anxious about vaginal delivery and that disclosure would probably affect her decision.

   The courts below assessed causation by concentrating on the small risk of grave injury rather than the risk of shoulder dystocia and its consequences. They also failed to consider material evidence about the likely response to disclosure. On the correct hypothesis of a dispassionate discussion without pressure, Mrs Montgomery would probably have chosen caesarean delivery, and the child would have been born unharmed. Conventional causation was therefore established, making it unnecessary to consider any alternative approach derived from Chester v Afshar [2004] UKHL 41.

1. United Kingdom Supreme Court: In Montgomery v Lanarkshire Health Board [2015] UKSC 11, the court unanimously allowed the appeal and reversed the conclusion that the consultant had neither breached her duty nor caused the injury.
2. Inner House of the Court of Session: The reclaiming motion was refused in [2013] CSIH 3; 2013 SC 245. The court upheld the Lord Ordinary’s application of the professional-practice test and his conclusion on causation.
3. Outer House of the Court of Session: In [2010] CSOH 104, the Lord Ordinary rejected both alleged grounds of negligence and found that disclosure would not have led Mrs Montgomery to choose caesarean delivery.