Bailey v The Ministry of Defence & Anor

In a cumulative-cause case, a claimant may establish causation by proving that the defendant’s breach made a material contribution, meaning a contribution greater than de minimis, to the condition which caused the injury. This approach modifies the ordinary but-for test where medical science cannot establish the counterfactual probability, but can establish a more-than-negligible tortious contribution.

The approach applies in medical negligence as in other fields. It does not apply where the evidence shows that the injury would have occurred from the non-tortious cause in any event, or where the alleged causes are distinct and independent rather than cumulative.

The claimant underwent an ERCP at Royal Haslar Hospital, managed by the Ministry of Defence. A conceded period of deficient post-operative resuscitation occurred on 11 and 12 January 2001. She subsequently endured serious complications, intensive treatment and surgery.

On 26 January, after transfer to a renal ward managed by the second defendants, she aspirated vomit, suffered cardiac arrest and sustained hypoxic brain damage. The claim against the second defendants was dismissed. Foskett J held the Ministry of Defence liable: [2007] EWHC 2913 (QB).

The Ministry appealed, challenging the counterfactual finding that earlier intervention would have occurred, the inference that weakness caused the aspiration, and the application of the material-contribution test for causation.

1. Appeal dismissed. Waller LJ gave the court’s judgment, with Sedley and Smith LJJ agreeing. The judge was entitled to find that, with proper overnight resuscitation and care, the claimant would probably have undergone further intervention on 12 January. That would have avoided at least part of the traumatic treatment which materially added to her later weakness.
2. The judge was also entitled to infer, as a matter of common sense, that the claimant’s generally weakened and debilitated condition prevented her from responding effectively to vomit and protecting her airway. No breach by the renal-ward staff broke the causal chain.
3. The weakness had two cumulative components: non-negligent pancreatitis and the consequences of the Ministry’s negligence. The judge could not quantify their relative potency, but was entitled to find that each made a material contribution to the overall weakness which caused the aspiration.
4. Bonnington Castings Ltd v Wardlaw [1956] AC 613 establishes that, in a cumulative-cause case, a contribution greater than de minimis is material. The ordinary but-for test is therefore modified where medical science cannot determine whether, but for the negligence, the injury would have occurred, but can establish a material tortious contribution. Wilsher v Essex Area Health Authority [1988] 1 AC 1074 was distinguishable because it concerned distinct possible causes, rather than cumulative causes. Conversely, where the non-tortious cause would have produced the injury in any event, as in Hotson v East Berkshire Area Health Authority [1987] 1 AC 750, no causative contribution is proved.

• Court of Appeal (Civil Division) — dismissed the Ministry of Defence’s appeal and upheld liability.
• High Court of Justice, Queen’s Bench Division — Foskett J found the Ministry of Defence liable in damages for the claimant’s brain damage: [2007] EWHC 2913 (QB).