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New judgment on patient consent

Post date: 22/08/2017 | Time to read article: 2 mins

The information within this article was correct at the time of publishing. Last updated 14/11/2018

new-judgmentThe law on “informed” consent has changed following a recent Supreme Court judgment

Clinicians must now ensure that patients are aware of any “material risks” involved in a proposed treatment, and of reasonable alternatives, following the judgment in the case Montgomery v Lanarkshire Health Board.

This recent case brings UK law into line with the consent that has been required in Australia since the 1992 case of Rogers and Whitaker*. While (until now) these principles only had practical application in Australia, all of Dental Protection’s advice on consent has reflected this position for over 20 years, so the recent UK decision will not be a surprise to many of our members.  This is a marked change to the previous application of the “Bolam test”**, which asks whether a clinician’s conduct would be supported by a responsible body of opinion amongst fellow clinicians working in the same field of medicine (or dentistry). The Bolam test, in relation to the disclosure of risks to patients when obtaining consent, was applied in the Sidaway case in 1985. The test will no longer apply to the issue of consent, although it will continue to be used more widely in cases involving other alleged acts of negligence. 

The new test

In a move away from the ‘‘reasonable doctor or dentist’’ to the ‘‘reasonable patient’’ as the new point of reference, the Supreme Court’s ruling outlined the new test described in the panel above. It is notable that this decision enshrines in law principles that are already in the GDC’s guidance in Standards for the Dental Team. 

The case

In 1999, Nadine Montgomery gave birth by vaginal delivery to Sam. The birth was complicated by shoulder dystocia. Medical staff performed the appropriate manoeuvres to release Sam but, during the 12-minute delay, he was deprived of oxygen and subsequently diagnosed with cerebral palsy.

Mrs Montgomery is diabetic and small in stature and the risk of shoulder dystocia was agreed to be 9-10%. Despite expressing concern to her consultant about whether she would be able to deliver her baby vaginally, the doctor failed to warn Mrs Montgomery of the risk of serious injury from shoulder dystocia or the possibility of an elective caesarean section.

Mrs Montgomery brought a claim against Lanarkshire Health Board, alleging that she should have been advised of the 9-10% risk of shoulder dystocia associated with vaginal delivery notwithstanding the risk of a grave outcome was small (less than 0.1% risk of cerebral palsy). 

Lanarkshire Health Board argued that only the risk of a grave adverse outcome triggered the duty to warn of such risks and that, because the risk of such an outcome was so low and that an expression of concern was not the same as a direct question requiring a direct answer, no warning was required.


The Supreme Court held that the question should have been about Mrs Montgomery’s likely reaction if told of the risk of shoulder dystocia. The unequivocal position was that she would have chosen to give birth by caesarean section.

The Bolam test was deemed unsuitable for cases regarding the discussion of risks with patients, as the extent to which a doctor may be inclined to discuss risks with patients is not determined by medical learning or experience.

The court ruled that Mrs Montgomery should have been informed of the risk of shoulder dystocia and given the option of a caesarean section. Mrs Montgomery was awarded £5.25 million in damages. 

*Rogers v Whitaker (Australia 1992) 175 CLR 479

**Bolam v Friern Hospital Management Committee (UK 1957) 1 WLR 58

« The cost of indemnity                                       10 What is happening at the GDC? »

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