Hotson v East Berkshire Area Health Authority [1988] UKHL 1 (02 July 1988)

A 13-year-old boy fell and fractured his hip. The hospital negligently failed to diagnose the injury for five days. He developed avascular necrosis causing permanent disability. The House of Lords held that since there was a 75% probability the damage was inevitable from the fall itself, causation was not established and damages for 'loss of chance' were not recoverable.

Facts

On 26 April 1977, Stephen Hotson, aged 13, fell approximately 12 feet from a rope at school, sustaining an acute traumatic fracture of the left femoral epiphysis. He was taken to St Luke’s Hospital, Maidenhead, operated by the defendant health authority. Hospital staff examined him but failed to diagnose the injury and sent him home. For five days he suffered severe pain until returning to hospital on 1 May 1977, when X-rays revealed the correct diagnosis. He was treated as an emergency and operated upon, but subsequently developed avascular necrosis of the epiphysis, causing permanent deformity of the hip with associated disability and the virtual certainty of osteoarthritis developing.

Medical Evidence

The trial judge heard conflicting expert medical evidence. The plaintiff’s expert suggested that even with prompt treatment, there was approximately a 40-60% chance of avoiding avascular necrosis. The defendant’s expert was emphatic that the initial traumatic rupture of blood vessels caused by the fall was so extensive that avascular necrosis was inevitable regardless of treatment. The judge found that there was a 75% probability that the plaintiff would have developed avascular necrosis even with prompt treatment, meaning the fall itself had left insufficient blood vessels intact to keep the epiphysis alive.

Issues

The central issue was whether the plaintiff could recover damages for the ‘loss of a 25% chance’ of avoiding avascular necrosis, despite the judge finding on the balance of probabilities that the fall itself was the sole cause of the condition. The question was one of classification: was this a case about establishing causation, or about quantifying damage for a lost chance?

Judgment

The House of Lords unanimously allowed the appeal, holding that the plaintiff had failed to establish causation on the balance of probabilities. The damages awarded for ‘loss of chance’ (£11,500) were therefore set aside.

Lord Bridge of Harwich

Lord Bridge held that the judge’s findings of fact were unmistakably to the effect that, on a balance of probabilities, the injury caused by the fall left insufficient blood vessels intact to keep the epiphysis alive. This amounted to a finding that the fall was the sole cause of the avascular necrosis. There was a clear conflict of evidence regarding causation which the judge had to resolve on the balance of probabilities. Unless the plaintiff proved that the delayed treatment was at least a material contributory cause of the necrosis, he failed on causation and no question of quantification could arise.

Lord Mackay of Clashfern

Lord Mackay emphasised that the fundamental question concerned a point in time before the negligent failure to treat began, making it a matter of past fact to be determined on the balance of probabilities. He cited Lord Diplock in Mallett v McMonagle: in determining what did happen in the past, the court decides on the balance of probabilities, treating anything more probable than not as certain. Lord Mackay considered it unwise to lay down as an absolute rule that a plaintiff could never succeed by proving loss of a chance in a medical negligence case, but distinguished the present case on its facts.

Lord Ackner

Lord Ackner stressed that to establish his cause of action, the plaintiff had to prove that the defendants’ breach of duty caused the injuries alleged. The judge had determined as a matter of fact that, on the balance of probabilities, the compression and blocking of blood vessels had no effect on the plaintiff’s ultimate condition. In determining what happened in the past, the court decides on the balance of probabilities and anything more probable than not is treated as certainty. The debate on loss of a chance cannot arise where there has been a positive finding that before the duty arose, the damage complained of had already become inevitable.

Implications

This case is a leading authority on the distinction between causation and quantification of damage in medical negligence cases. It establishes that where the question is one of historical fact (what was the patient’s condition at a given point), the court must determine that issue on the balance of probabilities. A plaintiff cannot recover a proportion of damages by characterising an improbable cause as a ‘lost chance’. Once causation is established on the balance of probabilities, full damages are payable; there is no discounting for uncertainty in proving causation. However, their Lordships declined to rule definitively that loss of chance can never ground recovery in medical negligence, leaving the question open for appropriate future cases.

Verdict: Appeal allowed. The award of £11,500 for ‘loss of chance’ was set aside. The plaintiff failed to establish on the balance of probabilities that the defendant’s negligence caused the avascular necrosis; the fall itself was found to be the sole cause.

Source: Hotson v East Berkshire Area Health Authority [1988] UKHL 1 (02 July 1988)