Davies v Frimley Health NHS Foundation Trust

In a clinical negligence claim involving death from bacterial meningitis, causation was determined on ordinary but-for principles and the balance of probabilities. Statistical evidence and clinical literature may assist, provided they are assessed critically and in the context of the individual case. The material contribution doctrine does not provide an additional route to liability for an indivisible injury where the court can decide whether the negligence caused the injury. In such a case, the court must determine the counterfactual as best it can from all the evidence. The claim succeeded because earlier intravenous antibiotics would probably have prevented death before the disease reached its tipping point.

The claimant, executor of Mrs Gabrielle Davies’ estate, sued the defendant NHS foundation trust after Mrs Davies died from pneumococcal meningitis following treatment at Wexham Park Hospital. Breach of duty was admitted: intravenous antibiotics should have begun by 10.40 on 25 February 2015. Quantum was agreed. The disputed issue was causation.

The claimant argued that timely antibiotics would probably have saved Mrs Davies, alternatively that the delay made a material contribution to her death. The defendant argued that the infection was already fulminant and irreversible by 10.40. The central questions were whether earlier treatment would probably have prevented death and whether material contribution could apply if ordinary causation was not established.

1. But-for causation. The court had to decide whether, on the balance of probabilities, Mrs Davies would have survived had intravenous antibiotics been administered by 10.40. Hindsight could properly assist, but it could not fill evidential gaps. Statistical evidence was not a rule of law and was not a direct guide to an individual case, but could contribute to the overall evidential picture when critically assessed by reference to the relevant cohort, variables, statistical analysis and clinical circumstances.
2. The general evidence showed that bacterial meningitis progresses rapidly, that antibiotics are effective if administered sufficiently early, and that treatment becomes ineffective after the disease reaches a self-reinforcing tipping point. Mrs Davies’ infection was aggressive, but remained treatable at 10.40. The tipping point was reached between 13.30 and 14.30. Antibiotics given at 10.40 would probably have reached the brain before that point and prevented death. But-for causation was therefore established.
3. Material contribution. The orthodox routes to liability are: contribution to divisible harm; causation of an indivisible injury on ordinary but-for principles; and co-liability where two wrongdoers together cause an indivisible injury but responsibility cannot be apportioned. Fairchild v Glenhaven Funeral Services Limited provides a distinct, narrow, risk-based exception.
4. The court rejected the submission that Bonnington Castings Limited v Wardlaw and Bailey v Ministry of Defence established a further general route to liability for indivisible harm where but-for causation could not be proved. Later authority treated those cases as involving orthodox principles concerning divisible or indivisible harm. Death from meningitis was an indivisible injury, and the only applicable question was whether the negligent delay caused it on the balance of probabilities.
5. Judgment was given for the claimant.