Gregg (FC) (Appellant) v. Scott (Respondent)

In clinical negligence, a claimant must prove on the balance of probabilities that the breach caused actionable personal injury. A reduced chance of cure or survival, without proof that negligence caused the adverse outcome, is not itself compensable. Possibilities may be valued when quantifying damage already shown to be attributable to the defendant; they cannot replace proof of causation.

The exceptional increased-risk rule in Fairchild v Glenhaven Funeral Services Ltd [2003] 1 AC 32 remains narrowly confined and does not govern ordinary delayed-diagnosis claims. A patient may recover for additional harm proved to have been caused by delay, but not merely because negligence statistically worsened the patient's prospects.

Dr Scott negligently failed to refer Mr Gregg for investigation of a lump which was non-Hodgkin's lymphoma. Treatment was consequently delayed by about nine months. The cancer spread, and Mr Gregg underwent extensive treatment and experienced relapses, pain, distress and loss of earnings.

The trial judge found that prompt treatment would probably have produced an initial remission. He could not find, however, that Mr Gregg would probably have avoided the later treatment and setbacks or achieved disease-free survival. The judge therefore dismissed the claim. A majority of the Court of Appeal, Simon Brown and Mance LJJ, dismissed the appeal; Latham LJ dissented: [2002] EWCA Civ 1471.

The central issue before the House was whether a reduced chance of cure or survival could itself constitute actionable damage in clinical negligence when the claimant could not prove on the balance of probabilities that the negligence caused the adverse outcome.

1. Disposition. The appeal was dismissed by a majority of three to two. Lord Hoffmann, Lord Phillips of Worth Matravers and Baroness Hale formed the majority. Lord Nicholls and Lord Hope dissented.

2. Conventional causation. Lord Hoffmann held that, subject to a narrowly defined exception, a claimant must prove on the balance of probabilities that the defendant's negligence caused or materially contributed to the actionable injury. An increase in the likelihood of injury is insufficient. The clinical outcomes in Hotson v East Berkshire Area Health Authority [1987] AC 750 and Wilsher v Essex Area Health Authority [1988] AC 1074 had determinate causes, although the available evidence could not identify them with certainty. The burden of proof governed that evidential uncertainty.

3. Causation and quantification. Lord Hoffmann and Baroness Hale rejected the argument that the reduced prospect of survival could be treated merely as quantification of physical injury caused by the delay. The principle in Mallett v McMonagle [1970] AC 166 permits possibilities to be considered when valuing damage already proved attributable to the defendant. It does not dispense with proof that the defendant caused the damage for which compensation is sought.

4. Loss of a chance. The majority declined to recognise the reduced chance of a favourable clinical outcome as a freestanding head of actionable damage. Lord Hoffmann considered that this would contradict existing authority and improperly generalise the exceptional rule in Fairchild v Glenhaven Funeral Services Ltd [2003] 1 AC 32. Lord Phillips considered percentage assessment difficult and potentially unreliable, particularly where the patient's condition continued to develop after trial. Baroness Hale concluded that combining conventional full recovery with proportionate loss-of-chance recovery would destabilise personal-injury law and make a defendant almost invariably liable for something.

5. Conventionally caused loss. Lord Phillips and Baroness Hale accepted that additional pain, suffering, financial loss or reduced life expectancy proved to have been caused by the diagnostic delay could be recoverable on conventional principles. Those matters had not been adequately explored before the trial judge, the facts were not reopened, and the House was not invited to remit the case for further findings.

6. Dissent. Lord Nicholls would have treated a significant diminution in recovery prospects as actionable where the outcome was affected by inherent medical uncertainty, irrespective of whether the original prospects exceeded 50%. Lord Hope agreed and additionally regarded the enlargement of the tumour as proven physical injury from which the reduced prospects flowed. They would have allowed the appeal and remitted the claim for assessment of damages.

• House of Lords: The appeal from [2002] EWCA Civ 1471 was dismissed by a majority of three to two, leaving the Court of Appeal's order standing.
• Court of Appeal: Simon Brown and Mance LJJ dismissed the appeal. Latham LJ dissented: [2002] EWCA Civ 1471.
• First instance: Judge Inglis found that the doctor had been negligent but dismissed the claim because causation of the claimed loss had not been proved. He considered himself constrained by Hotson v East Berkshire Area Health Authority [1987] AC 750.