Ratio Decidendi
English law does not recognise a claim for loss of a chance of a better medical outcome. Where the claimant's pre-existing chance of a good outcome was less than 50%, the reduction of that chance by negligence does not give rise to a claim in negligence.
Facts
A GP negligently failed to diagnose non-Hodgkin's lymphoma. The delay reduced the patient's chance of disease-free survival from 42% to 25%.
Judgment Summary
The House of Lords (3–2) dismissed the claim. The majority held that 'loss of a chance' was not recoverable in clinical negligence. Since the claimant could not prove on the balance of probabilities that he would have been cured but for the negligence, causation was not established.
Key Quotes
"A wholesale adoption of possible rather than probable causation would be so radical a change in our law as to amount to a legislative act."
— Lord Hoffmann
Subsequent Treatment
Controversial authority; loss of chance remains unavailable in clinical negligence despite academic criticism.