Material contribution, drawing adverse inferences from absent witnesses and the relevance of Trust guidelines – the lessons of Thorley v Sandwell & West Birmingham Hospitals NHS Trust [2021] EWCH 2604 (QB)

This unusual case was successfully defended by Pearl Mullen from our Birmingham office recently. It required the Court to consider three separate issues of significance to the cases we all handle every day. In it, the Judge had to grapple with:

a) When should a Judge draw an adverse influence when a witness isn’t called?

b) Which sets the level for the legal duty of care – a Trust Guideline or the cases of Bolam and Bolitho?

c) When can a Claimant legitimately rely on ‘material contribution to establish causation?

Having a case which addressed one of these issues of principle would be unusual, but addressing all three puts it in a different category of significance altogether.


The Claimant had a history of atrial fibrillation and had been prescribed long-term warfarin.

On 27 April 2005 he underwent an angiogram and had been advised to stop warfarin 4 days prior to the procedure. The Trust then advised him to re-start it 2 days after the angiogram (29 April 2005), which it was admitted was one day too late. Unfortunately, he suffered a stroke caused by a blood clot on 30 April 2005.

Breach of duty

The Claimant’s case was that:

  • An internal Trust Guideline indicated that the Claimant should have been advised to stop taking warfarin three (rather than four) days before the angiogram.
  • Based on the same guideline (and the Claimant’s expert opinion) warfarin should have been restarted on the day of the procedure rather than two days later.

The Defendant Trust had already admitted a breach of duty for not restarting warfarin the day after the angiogram but maintained that it was reasonable to stop warfarin four days before and to restart it one day after the procedure. The Trust argued that the 2004 Guideline applied only to surgery and did not cover coronary angiograms. Although it called no factual evidence on the point, its experts supported that interpretation.

In finding for the Defendant on all issues, Mr Justice Soole made specific findings on the three areas set out at the start of this article.

a) Adverse Inference

As the Trust had not served any witness evidence from the writers of the Guideline to confirm that it did not apply to angiograms, the Claimant asked the Court to infer that such evidence would in fact have proved that it did.

The Judge declined to draw that inference. Whilst he decided that he was free to draw that inference if he wanted to do so, he felt that the wording and contents of the Guideline clearly meant it applied to surgical cases, not angiograms. He concluded that there was no basis on which to draw the inference the Claimant was asking him to.

b) Which takes precedence – the Guideline or Bolam/Bolitho?

Mr Justice Soole then went on to consider the status of the Guideline and how it would have affected the standard of care to be applied in the case, if he had found that applied and it set a higher standard than was applicable under Bolam.

He concluded that it was the Bolam test that set the standard, not the Guideline, as the test was a legal one “determined by authority at the highest level”. In any event it was more accurate to regard the Guideline as setting out a ‘different’ practice by clinicians rather than a ‘better’ one. The expert evidence provided no basis for concluding that a 3 day omission of warfarin was ‘better’ practice than 4 or 5 days. Considering Bolitho, he also decided that the existence of a guideline, even if applicable, does not make it illogical to apply the alternative and responsible practice of a body of competent practitioners.  

c) Causation and the doctrine of material contribution

The Claimant had argued his case on both ‘but for’ causation and ‘material contribution’. Dr Baglin, the Claimant’s expert haematologist, had originally accepted that it was not possible to say that but for the failure to restart warfarin earlier post-procedure, the Claimant’s stroke would have been avoided. If the Guideline had been followed and warfarin stopped one day later pre-procedure, however, he concluded that it would have been and ‘but for’ causation could be established.

Having heard evidence from the experts, Mr Justice Soole preferred the evidence of the Defendant’s haematology expert (Professor Pasi) on the point and concluded that, on the balance of probability, even if the omission of warfarin had been for an overall total of three, four or five days instead of six days, the Claimant’s stroke would have occurred in any event.

The only remaining issue was that of material contribution. Did the reduced anti-coagulation materially contribute to the stroke and, if so, did that help the Claimant’s case?

Dealing with the first of those two points, the Judge noted that Dr Baglin was not in fact saying that the reduced anti-coagulation materially contributed to the stroke itself, but to the risk of a stroke. Each day that passed did not (in the Judge’s conclusion) contribute to the occurrence of injury, but only to the risk of that injury occurring. That was insufficient to establish causation unless the claim fell within what is known as the Fairchild exception (which applies to mesothelioma/cancer cases).

Even if the Judge had not come to this decision, however, the Claimant still had to apply the principle to his case. The Judge decided that he could not do that either. The stroke was a single event – in law an ‘indivisible’ injury. As such, the Judge concluded that established case law confirmed that the modified causation test of material contribution was not applicable. The Judge did note, however, that the decision of the Privy Council in Williams v The Bermuda Hospitals Board had come to a different decision, but he decided that was not strictly binding on him (being a decision of the Privy Council). He noted, as have many before him and (no doubt) many more will, that this area of law was “ripe for authoritative review” and highlighted the need for clarity.


This was a comprehensive decision in which the Judge found in favour of the Defendant Trust on all points.  Perhaps the most notable legal issue, though, was the approach the Judge took to the Claimant’s attempts to rely on ‘material contribution’ to assist them in establishing causation, indicating that he felt neither bound nor persuaded by the Privy Council’s decision in Williams. His analysis of the authorities makes it clear that both confusion and uncertainties in this area remain rife, as successive courts have refused to grasp the nettle and provide clear, unequivocal and readily understandable guidance to practitioners.

If you would like to discuss this topic in more detail please contact Adrian Dagnall, Partner, Pearl Mullen, Solicitor or Samantha Ross, Paralegal.

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