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Weighing the risks

15 Jun 15

The UK Supreme Court has altered the duty on a doctor when giving advice about treatment, in relation to possible risks to the patient. What are the implications?

by Geoffrey D Mitchell QC

There has been a recent and important change to the law of clinical negligence that practitioners will wish to be aware of when advising clients. In Montgomery v Lanarkshire Health Board [2015] UKSC 11; 2015 SLT 189 the Supreme Court departed from the House of Lords decision in Sidaway v Board of Governors of the Bethlem Royal Hospital and the Maudsley Hospital [1985] AC 871, the consequence of which is to alter the approach that the law requires a medical practitioner to adopt when advising a patient of the risks of treatment.

The facts in Montgomery

The pursuer was expecting her first baby. She was quite small in stature and suffered from diabetes. This condition meant that there was a likelihood that her baby would be larger than normal, and thus an increased likelihood of shoulder dystocia (a difficulty in delivering the baby as it passes through the mother’s pelvis, due largely to the size of the shoulders). Accordingly, her pregnancy was classified as high risk. In the pursuer’s case the risk of shoulder dystocia was 9% to 10%.

Although the majority of cases are resolved by changing the position of the mother, and although the mother may not often be aware of the complication, there remains a risk to the mother of postpartum haemorrhage and perineal tears. There is also a risk of damage to the baby’s shoulders and to the nerves that lead from the shoulders to the spinal cord (a risk of 0.2% in diabetic mothers). In a small number of cases the umbilical cord can become trapped against the pelvis, resulting in a reduction in the flow of oxygen to the baby, leading to cerebral palsy or death (a risk of less than 0.1% in diabetic mothers).

The pursuer expressed concern to the doctor who was supervising her pregnancy about the size of her baby, and whether she would be able to deliver it vaginally, but did not ask about specific risks surrounding vaginal delivery, nor about the option of caesarean section. In accordance with her normal practice, the doctor (an experienced and respected consultant obstetrician and gynaecologist) did not mention the risk of shoulder dystocia to the pursuer, since the risk of serious injury to the baby was very small. She felt that mention of the risk of shoulder dystocia to a diabetic mother would prompt a request for a caesarean section. This procedure, she felt, was not in the maternal interest. If shoulder dystocia was encountered during birth then a caesarean section could, if necessary, be performed.

Her decision not to discuss the risk of shoulder dystocia with the pursuer was supported by two prominent and independent expert obstetricians, who gave evidence on behalf of the defenders. During labour the baby’s shoulder became impacted on the pelvis and a period of 12 minutes passed during which the umbilical cord was occluded. The baby was diagnosed as suffering from cerebral palsy and paralysis of the arm.

In the Court of Session the pursuer argued that she should have been advised of the risk of shoulder dystocia, and been offered the alternative of caesarean section, which would have resulted in the baby being born uninjured.

Doctors know best?

Both the Lord Ordinary and the Inner House of the Court of Session rejected this argument. They applied the test set out in Sidaway. Whether a doctor was negligent in omitting to tell a patient of risks depended on whether the omission could be supported as proper by a responsible body of medical opinion.

Essentially, what was communicated to the patient was a matter for the skill and judgment of the doctor. This was the same test that applies to cases of diagnosis and treatment: cf Hunter v Hanley 1955 SC 200, and Bolam v Friern Hospital Management Committee [1957] 1 WLR 582. In view of the expert evidence led by the defenders, the pursuer could not meet this test.

The court recognised that there were situations where, notwithstanding the existence of a responsible body of medical opinion that supported the doctor, the court could nevertheless find the doctor to have been negligent. Such a situation arose where there was “a substantial risk of grave adverse consequences”, such that “the disclosure of a particular risk was so obviously necessary to an informed choice on the part of the patient that no reasonably prudent medical man would fail to make it” (per Lord Bridge in Sidaway). However, this was not such a situation, since the risk of cerebral palsy or death of the baby was assessed at less than 0.1%. Further, although a doctor was bound to answer fully any specific questions from a patient about risks, the general expression of concern by the pursuer regarding the size of her baby and her ability to deliver it vaginally did not trigger the doctor’s duty of disclosure.

In short, the pursuer was unable to establish negligence. She appealed to the Supreme Court.

Information age

The court decided that the pursuer ought to have been told of the risk of shoulder dystocia, and given the option of caesarean section. The court considered that the Hunter v Hanley/Bolam test should no longer apply to cases where advice is given to patients about treatment. There was a fundamental distinction between, on the one hand, the doctor’s role when considering possible investigations or treatment options and, on the other hand, the doctor’s role when discussing with the patient recommended treatment, possible alternatives and any risks involved. The latter may involve skill and judgment (for example, in explaining the risks), but it was not the kind of skill and judgment with which Hunter v Hanley is concerned.

It was unsatisfactory that the decision on what to tell a patient rested with the doctor. Social and legal changes have produced a society wherein patients are well informed and able to process information that is communicated to them. It was important that the law treats them as adults who understand that medical treatment involves risks, but who accept responsibility for that treatment, and who live with the consequences. This must be a better state of affairs than when the patient is “kept in the dark” by the doctor about proposed treatment, and then sues when the outcome is not as expected.

Accordingly, the duty on a doctor when giving advice about treatment is “to take reasonable care to ensure that the patient is aware of any material risks involved in any recommended treatment, and of any reasonable alternative or variant treatments. The test of materiality is whether, in the circumstances of the particular case, a reasonable person in the patient's position would be likely to attach significance to the risk, or the doctor is or should reasonably be aware that the particular patient would be likely to attach significance to it” (per Lord Kerr and Lord Reed, para 87).

In this case, the risk of shoulder dystocia was high (9% to 10%). Although the risk of injury to or death of the baby was low, shoulder dystocia posed significant risks to the mother’s health, and was traumatic. By contrast, caesarean section posed very little risk to mother and baby. (The court said that there may be two “exceptional” situations where a doctor may be entitled to withhold information about risk: first, where the disclosure would be damaging to the health of the patient; secondly, where urgent treatment was required but the doctor is unable to confer with the patient, e.g. where the patient is unconscious. Neither exception applied in this case.)

Discussion: onus on the doctor

It is important to bear in mind that doctors always act in the best interests of their patients, as did the doctor in the present case. The change effected by Montgomery is that, in the realm of advice and disclosure of risks, the decision as to what constitutes the “best interests of the patient” is not now exclusively one for the doctor. Many factors may influence a patient when pondering a medical procedure, not all of them connected with relief of pain. For example, changes in body appearance consequent on a procedure may be equally important to that patient, and will form an important consideration in deciding whether to proceed. That may not be obvious to the doctor. In essence, it is for the patient to take responsibility, and to decide what is in his or her best interests.

Doubtless, many doctors currently practising have the type of full and comprehensive discussion with a patient that is envisaged by the Supreme Court. Indeed, the General Medical Council has long advocated that their members should have such discussions with patients. Certainly the writer is aware of sectors within the NHS where extremely comprehensive discussions take place. On one view, therefore, Montgomery might simply be seen as the law “catching up” with current medical practice. However, there will undoubtedly be cases where lack of time, or pressure on resources, leads to a less than satisfactory discussion. What Montgomery does do is to make clear that, should a patient suffer an injury that could have been avoided through the disclosure of a material risk, a doctor cannot rely for protection on a “responsible body of medical opinion” (i.e. that other doctors would have done the same).

The onus on the doctor is to take reasonable care to advise the patient of risks. This has several consequences. The patient who does not know what to ask, or who is afraid to ask, is relieved of a burden. Further, the duty is one of reasonable care. It is not an absolute duty. An important factor in assessing whether the doctor has exercised reasonable care will be an examination of the risks that have been disclosed. The duty is to disclose material risks, insofar as those are significant to the particular patient. What is “material” will vary from patient to patient. Some risks will be more important to some patients than to others. To borrow the example from the case of Rogers v Whitaker (1992) 175 CLR 479, a patient who is blind in one eye would be concerned (and reasonably so) about any risk involved in an operation to the good eye. A doctor would be acting with reasonable care if they advised the patient of all risks, and possible alternatives, no matter how small.

It would seem that there will be a continued need for expert evidence. The court has said that the significance of the risk will reflect a variety of factors, including the nature of the risk, the alternatives available and the risk involved in those alternatives. Evidence from an appropriately qualified expert would seem to be essential, along with evidence from the pursuer as to how he or she expected to benefit from the treatment.

The Supreme Court considered that the change in the law should lead to a reduction in litigation: the patient to whom a full disclosure of risks has been made, and who has taken responsibility for the decision to proceed with treatment, is less likely to be dissatisfied with a procedure that does not produce the expected outcome. Only time will tell whether the court will be proved correct.

Geoffrey D Mitchell QC, director of the Ampersand set of advocates, specialises in clinical negligence


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