Demery v Cardiff and Vale NHS Trust

In a clinical negligence claim, causation must be determined on the balance of probabilities by examining the particular facts and the medical evidence. A court must assess the consequences of negligent delay, including any worsening of the injury, rather than decide solely by general assumptions.

Where an operation is normally successful, that background is relevant when considering an unusual failure. Statistical rarity does not itself prove causation, but it should not be disregarded. The court must confront whether the negligent delay and its consequences provide the most probable explanation. An appellate court should intervene where material evidence has been misunderstood or material issues lack reasoned findings. If unresolved issues remain, the appropriate course is remission for rehearing.

Dawn Demery injured her ankle while ice skating. The respondent admitted that the appellant’s ruptured ankle ligaments should have been diagnosed and treated on her first hospital attendance and that the failure was negligent. Causation was disputed because the respondent contended that the later failure of the syndesmosis and resulting disability would have occurred in any event.

His Honour Judge Hickinbottom, sitting in Cardiff County Court, dismissed the claim on 1 February 2006. The appeal concerned whether the judge had omitted material evidence, misunderstood the experts’ evidence and failed properly to assess the effects of the delay, and whether the Court of Appeal should determine causation itself or remit the matter.

1. Appeal allowed and case remitted. The Court of Appeal held that the judgment could not stand and remitted the case generally for consideration by a trial judge. The appellant’s costs of the appeal were payable by the respondent. The costs of the trial below were costs in the case.
2. Per Lord Justice Pill, the trial judge had failed to make reasoned findings on material matters relied upon by the appellant. In particular, he had not properly addressed the increased gap between the tibia and fibula, the increased subluxation, or the consequences of the negligent delay. He had also misunderstood or materially misstated important aspects of the evidence of Mr Pearse and Mr Smith.
3. Causation had to be determined on the balance of probabilities. The particular facts had to be considered in the light of the medical evidence. The issue was whether the delay, together with its consequences—including weight-bearing, increased swelling, increased separation and worsening subluxation—had caused or contributed to the failure of the syndesmosis. The decision could not properly be based on assumptions about the effect of delay.
4. The operation ordinarily produced healing and a good recovery. Lord Justice Pill held that this high success rate was relevant background evidence. The judge therefore had to consider what factors present in this case could explain the unusual failure, particularly where the other explanations relied upon had been rejected. Lady Justice Smith agreed with Lord Justice Pill’s conclusion that the appeal should be allowed and remitted.
5. Lord Justice Neuberger agreed with the disposition but adopted narrower reasoning. He considered that Mr Pearse’s evidence required further investigation and that the judge’s treatment of it was inaccurate or materially incomplete. He would not himself have relied on the statistical rarity of failure as assistance in resolving causation without other evidence linking the delay to the outcome. This difference did not affect the need for a rehearing.

• Court of Appeal (Civil Division) — [2006] EWCA Civ 1131: appeal allowed; case remitted generally for consideration by a trial judge.
• Cardiff County Court — His Honour Judge Hickinbottom, 1 February 2006: claim for damages dismissed on causation grounds.