Medical negligence and the loss of chance

Doctors, dentists, and other health professionals have a duty of care towards their patients, requiring them to treat their patients with reasonable skill and care. Where a doctor or other health professional breaches this duty which results in personal injury to the patient or contributes to making another condition worse, a claim for compensation for medical (or clinical) negligence may follow.

To make a successful compensation claim for medical negligence, a claimant needs to show the doctor owed them a duty of care; this duty was breached; and the claimant suffered personal injury as direct result of the breach.

The losses a claimant suffers, or expects to suffer in future, as a result of the personal injury sustained following medical negligence may include ‘loss of chance’. It requires them to show that the defendant’s negligence caused them to lose the opportunity of some favourable outcome, which could include the loss of the chance of future higher earnings.

In the famous case of Chaplin v Hicks [1911-13], the claimant successfully claimed for loss of the chance to win a beauty contest after the defendant negligently omitted to include her in an earlier round of the competition.

Attempts to extend the loss of chance principle to medical negligence cases, however, have met with little success. The House of Lords has twice refused to impose liability on a defendant accused of losing the claimant a chance of avoiding harm or injury.

In Hotson v East Berkshire Area Health Authority [1987] the House of Lords held that since, on the balance of probabilities, the condition was bound to develop even with the right diagnosis and treatment, he had not established causation. In Gregg v Scott [2005], meanwhile, the court held that a claim against a doctor who has negligently caused a reduction in the prospects of a successful recovery will fail on causation grounds if the claimant cannot prove that, on balance of probability, he would have recovered.

The House of Lords cited numerous public policy concerns for not extending the loss of chance principle to the sphere of clinical negligence, including a loss of certainty in the law, the adverse affects on the NHS, the difficulty of reconciling loss of chance arguments with existing and longstanding tortious principles in the personal injury field and the wide scope of any such restatement of the law and the trouble of confining its application within bounds.

In his judgment in Gregg v Scott, Lord Phillips said: ‘The complications of this case have persuaded me that it is not a suitable vehicle for introducing into the law of clinical negligence the right to recover damages for the loss of a chance of a cure. Awarding damages for the reduction of the prospect of a cure, when the long-term result of treatment is still uncertain, is not a satisfactory exercise.’

Lord Phillips arguably left one small window open to claimants when he said: ‘Where medical treatment has resulted in an adverse outcome and negligence has increased the chance of that outcome, there may be a case for permitting a recovery of damages that is proportionate to the increase in the chance of the adverse outcome. That is not a case that has been made out on the present appeal.’

If the claimant can successfully establish causation on the balance of probability in his claim, however, the courts have shown themselves willing to reflect loss of opportunity in quantifying damages (eg, Doyle v Wallace [1998]).

Taking all these cases together, the following principles emerge:

• compensation for loss of chance in medical negligence cases can only be recovered in very limited circumstances;
• claims are dealt with subjectively, depending on the specific facts of the case;
• causation is a critical factor: if, for instance, the claimant cannot show that on the balance of probabilities the treatment would have made a difference to their survival, they will not succeed;
• exceptionally strong evidence as to the claimant’s past capabilities may mean a claim for loss of chance succeeds (XYZ v Portsmouth Hospitals NHS Trust (2011));
• both expert evidence and factual evidence is critical to successful loss of chance claims; speculative claims will not succeed;
• in the case of delayed treatment, a claimant who cannot prove that the negligence caused or materially contributed to a resulting injury may lose their loss of chance claim (Hotson).