Gregg v Scott

In a clinical-negligence claim, the claimant must generally prove on the balance of probabilities that the negligence caused the relevant injury or substantive head of loss. A statistically reduced chance of cure or survival is not recoverable merely because negligence caused a condition that worsened the prospects. The claimant must establish causation of the relevant loss.

Where physical injury is established, consequential pain, treatment and future risks arising from that injury may be assessed by reference to prospects. The exceptional material-increase-in-risk approach applies only in narrowly defined evidential-gap cases. The majority dismissed the appeal; Latham LJ would have awarded damages for the significant lost chance.

The appellant’s general practitioner negligently failed to refer a lymphoma for specialist diagnosis, causing about nine months’ delay. The tumour enlarged and the appellant underwent more intensive treatment. The High Court found that the delay reduced his statistical chance of disease-free survival from 42% to 25%, but dismissed the claim because it was not more probable than not that earlier treatment would have produced a materially better ultimate outcome.

The appeal concerned the proper distinction between causation and quantification, the application of Hotson, and whether the reduced chance of cure or survival could be recovered as damage.

The appeal was dismissed by a majority. Mance LJ gave the principal reasoning and Simon Brown LJ agreed. Latham LJ dissented.

1. Majority: ordinary causation. Mance LJ held that a claimant must generally prove on the balance of probabilities that the relevant injury arose from the defendant’s negligence. The material-increase-in-risk approach in Bonnington Castings, McGhee and Fairchild was exceptional. It addressed a critical evidential gap and did not generally apply to a doctor’s failure to diagnose a pre-existing disease.
2. Nature of the loss. The enlarged tumour was a physical consequence of the negligence. Extra pain, suffering and treatment attributable to it could be recoverable. However, diminished life expectancy was a substantive head of loss. The claimant had to prove that the negligence caused that diminution on the balance of probabilities. It was impermissible to treat the enlarged tumour as the actionable injury and the reduced life expectancy as a merely parasitical consequence when the claimant could not show that the life-expectancy loss would otherwise have been avoided.
3. Causation and quantification. The distinction between causation, hypothetical facts and quantification was not always clear-cut, and the trial date did not by itself determine the classification. Statistical prospects could be used to value future risks after causation of an injury had been established. They could not establish a substantive life-expectancy loss which remained unproved on the balance of probabilities. Hotson was not directly on all fours because it concerned an all-or-nothing injury, but its treatment of the relevant causation issue remained important. Fairchild did not create a general relaxation of causation in medical negligence.
4. Simon Brown LJ. He found no principled distinction between the physical effects of the delay here and those in Hotson. Although the loss-of-chance issue deserved a clearer resolution, Fairchild did not justify a general departure from probability-based causation. He therefore dismissed the appeal.
5. Dissent. Latham LJ considered that the negligent spread of a treatable tumour was an established injury and that the significant reduction in the chance of cure could be quantified using statistical evidence. He distinguished Hotson and would have allowed the appeal.

1. Court of Appeal (Civil Division): By a majority, dismissed the appeal. Mance LJ and Simon Brown LJ agreed; Latham LJ dissented.
2. High Court of Justice, Queen’s Bench Division: HHJ Inglis dismissed the claim after finding that the delay reduced the appellant’s prospects but did not establish, on the balance of probabilities, that the ultimate outcome would have been materially different.