Watts v North Bristol NHS Trust [2022] EWHC 2048 (QB)

Snow v Royal United Hospitals Bath NHS Foundation Trust [2023] EWHC 42 (KB)

Two cases from the past year illustrate the importance of factual causation as an issue in litigation concerning consent to treatment and provide various reminders on points of practice that will be of interest to those working in the field of clinical negligence.

In Watts v North Bristol NHS Trust [2022] EWHC 2048 (QB) Bourne J heard an appeal from the County Court in a case concerning spinal surgery. The Claimant suffered from back and leg pain along with numbness and some weakness. He attended a consultation with a spinal surgeon on a private basis, following which microdiscectomy was proposed. The Claimant then attended an NHS consultation with a different surgeon who proposed spinal fusion instead. The Claimant went ahead with spinal fusion with regrettably poor results. The judge at first instance found that there had been a failure by the NHS consultant to advise on the pros and cons of microdiscectomy as an alternative to fusion and that the Claimant’s informed consent was not therefore obtained.

However, the claim failed on factual causation – the Claimant had failed to prove, on the balance of probabilities, that he would have chosen microdiscectomy over fusion. The trial judge had, in particular, been concerned by the failure of the Claimant’s first witness statement to address, at all, the issue of why microdiscectomy would have been preferred. The Claimant’s second statement, served close to trial, failed, in the judge’s view, adequately to provide reasons for preferring microdiscectomy, other than it being less invasive and a shorter procedure. Microdiscectomy produces a different outcome from fusion, in that it only treats nerve compression and referred pain, not constitutional back pain, spinal ‘tilt’ or instability, whereas fusion would in principle address all aspects.

The judge directed himself by reference to Smith v Barking, Havering and Brentwood Health Authority [1994] 5 Med LR 285, in which Hutchison J referred to the difficulty for a claimant in giving reliable answers to this type of question after the event and added:

“Accordingly, it would, in my judgment, be right in the ordinary case to give particular weight to the objective assessment. If everything points to the fact that a reasonable plaintiff properly informed, would have assented to the operation, the assertion from the witness box made after the adverse outcome is known, in a wholly artificial situation and in the knowledge that the outcome of the case depends upon that assertion being maintained, does not carry great weight unless there are extraneous or additional factors to substantiate it. … Of course the less confidently the judge reaches a conclusion as to what objectively the reasonable patient might be expected to have decided, the more readily will he be persuaded by her subjective evidence.”

The Claimant appealed against the judge’s finding on the point of factual causation, arguing that the judge himself was guilty of a lack of reasoning in his rejection of the Claimant’s evidence as to which procedure he would have chosen. Bourne J, in rejecting this ground of appeal, noted at [40] that the:

“…question for me on this appeal is not whether I would have made a different finding but whether I am satisfied that the Judge’s finding of fact was plainly wrong, meaning that it was a finding which no reasonable Judge could have reached. For that proposition, see Henderson v Foxworth Investments Ltd [2014] UKSC 41, [2014] 1 WLR 2600 at [62]…

and that this gave rise to a:

“…high hurdle necessary to overturn a finding of fact” [46].

He noted at [48]:

“[The Claimant] supported his assertion by claiming that the choice was an obvious one. The Judge was entitled to, and did, reject that view. Choosing microdiscectomy would have meant rejecting the strong advice of the surgeon who was, in effect, standing by to operate. In particular it would have meant rejecting his advice about “tilt” and instability. It would also have meant giving up a likelihood of the back pain being relieved. Whilst there were also factors leaning in favour of microdiscectomy, the Judge was entitled not to be persuaded that they made the choice obvious. Indeed, if microdiscectomy was the obvious choice, then [the NHS surgeon’s] advice to opt for fusion would have been irrational, but the expert witnesses at the trial agreed that that advice was reasonable.”

By contrast, Snow v Royal United Hospitals Bath NHS Foundation Trust [2023] EWHC 42 (KB) was a case in which the court (HHJ Richard Roberts, sitting as a Judge of the High Court) was ready to conclude that, with proper discussion of the options, the patient would have made a different choice.

The case concerned surgery for rectal cancer. The two surgical techniques under consideration were Total Mesorectal Excision (TME) and Trans-anal Total Mesorectal Excision (TaTME). The perceived advantage of the latter was a lower risk of permanent colostomy being required. The Claimant underwent TaTME but unfortunately suffered complications namely impotence, urinary and faecal incontinence, exacerbation of lower anterior resection syndrome (LARS) and psychiatric injury.

The Defendant accepted that there had been a negligent failure to counsel the Claimant of the risk of LARS, urogenital injury and of reverting to an open procedure. However, the Claimant’s case went further – that there was a failure to advise the Claimant, first, that his surgeons had performed only one TaTME previously and that the evidence suggested a higher risk of unfavourable outcomes early in the learning curve and, second, that NICE Guidance stated that there was insufficient evidence to know if TaTME was safe enough and works well enough. By way of background to the latter point, the judge was asked to consider the extent to which the practice in this case had departed from NICE Guidance. Whilst reminding himself that failing to follow NICE guidance is not prima facie evidence of negligence, but that to do so calls for some sort of explanation (as per Price v Cwm Taf University Health Board [2019] PIQR P14), the Judge considered that there had been multiple departures from those recommendations without good explanation. He noted at [107] that the operating surgeon accepted in evidence that the Claimant was not informed of six out of the seven material risks identified by NICE. With the addition of the failure to inform the Claimant of the number of such surgeries performed by the surgeon, it was a short step to find that, with this information, the Claimant would have elected instead for TME.


These cases serve to illustrate the necessity of careful consideration on both sides as to factual causation in consent cases. It is likely to be insufficient for a claimant merely to assert (after the event) that they would have elected to undergo an alternative procedure (or none at all); the evidence on both sides must address the counterfactual position of what would have been decided if a bare minimum of adequate information as to the alternatives was made available. Sometimes that will be rendered more complicated by dispute as to what the alternatives in fact were and/or what should have been said about them; however, a claim that does not address these points risks failing for want of proof.

Some other practitioner points arising from the cases include Bourne J’s observation at [69] of Watts in respect of the joint statement that: “In my view the experts were asked far too many questions, causing the document to be weighed down with material that did not identify their positions on the decisive issues. Some of the experts’ answers did not begin by identifying agreement or disagreement and/or were discursive rather than concisely identifying the differences between their positions.”

Also, at [173-175] of Snow, the pitfall of an expert having failed to read all the literature relied on by the other side before entering the witness box (including where necessary seeking out copies of published literature rather than expecting it to be provided by the opposing party).

Matthew Barnes appeared for the Defendant/Respondent in Watts v North Bristol NHS Trust. He did not contribute to this article.