Legal Case Summary
Wilsher v Essex Area Health Authority [1988] AC 1074
Claimant always holds the burden of proving likely causation
Facts
An infant was delivered prematurely and shortly after was administered oxygen by a junior doctor, accidentally providing too much. The baby was later diagnosed with a retinal condition, which severely limited his sight. Five potential causes or factors were identified to explain the condition, four relating to his premature birth and the fifth being the junior doctor’s actions.
Issues
Whether the health authority for which the junior doctor worked could be held liable for his actions where it could not be definitively stated what the chief cause of the injury was. Moreover, should a junior doctor be held to the same professional standards as a fully qualified doctor. Further, should the burden of proof regarding the potential relationship between the negligent actions and the injuries fall to the claimant or the defendant.
Decision/Outcome
At first instance the Court found the defendant, Essex Area Health Authority, liable for the infant’s injuries, citing McGhee v National Coal Board [1973] 1 WLR 1 as laying down the precedent that where there existed a plurality of possible causes, the burden fell to the defendant to prove that their actions had not been the but for or material cause of the injury.
The House of Lords subsequently allowed the defendant’s appeal and overturned the first instance judgment stating that whilst the health authority could be held liable for the junior doctor’s actions as junior doctors owed the same duty of care as a fully qualified doctor, the case of McGhee had been wrongly interpreted at first instance; regardless of the number of potential causes of injury, it always falls to the claimant to establish the likelihood of causation.
Updated 20 March 2026
This summary remains broadly accurate as a description of the House of Lords’ decision in Wilsher v Essex Area Health Authority [1988] AC 1074. The core holdings — that the burden of proving causation rests on the claimant, and that a junior doctor is held to the same objective standard of care as a fully qualified doctor in the relevant post — continue to represent good law in England and Wales.
One clarification worth noting: the article describes the causation standard as the ‘but for or material cause’ test. Since Wilsher, the law on causation has been further developed, most significantly by the House of Lords in Fairchild v Glenhaven Funeral Services Ltd [2002] UKHL 22 and subsequently by the Supreme Court in Sienkiewicz v Greif (UK) Ltd [2011] UKSC 10. These cases refined when the ‘material contribution to risk’ principle (drawn from McGhee v National Coal Board) can exceptionally apply, confirming that the Wilsher restriction — that the exception does not apply where multiple independent potential causes are present — remains central to that analysis. Students should read Wilsher alongside this later case law to understand the full current position on causation in negligence.
