UK: Loss of Chance? Probably Not

Last Updated: 13 February 2002

Originally published in January 2002

The recent decision of the Court of Appeal in Webb v Barclays Bank Plc & Portsmouth Hospitals NHS Trust1 is not one to set pulses racing. However, at first blush (and at first instance) a few eyebrows were raised as Rougier J opted in April 2000 to assess damages as a lost chance instead of using the traditional "but for" test. Clinical negligence claims potentially took on a different complexion, albeit briefly.

The claimant was a 45 year old bank employee. In January 1994 she tripped at work, causing increased pain and disability to the left knee. After advice from a consultant orthopaedic surgeon, she underwent an above-knee amputation in February 1995. She sued Barclays for damages for personal injury. Barclays contended that the above-knee amputation had been unnecessary and the claimant joined the NHS Trust as a second defendant. Barclays sought a contribution from the Trust.

The claimant’s claim was settled in full by Barclays shortly before trial. The contribution proceedings continued to trial and judgment was given on 13 April 2000.

Rougier J concluded that the consultant orthopaedic surgeon had negligently failed to advise the claimant of treatment options alternative to amputation. However, he found causation difficult. He accepted that, in ordinary circumstances, the test for assessing the extent of recoverable damage (if any) would be:

"... whether on the balance of probabilities, the claimant succeeded in proving, either by direct evidence or necessary inference that she would have ... avoided amputation and its consequences"

However, he took the view that he did not have sufficient evidence before him to apply that test. Instead, he assessed the claimant’s "loss of a chance" of avoiding amputation, valuing that lost chance at 40%. He conceded that this was a speculative exercise.

The Trust appealed, contending that the wrong test had been applied. The correct approach, they said, was to decide whether the claimant would have undergone amputation in any event, on the balance of probabilities. As the judge had concluded that there was insufficient evidence that the claimant would have avoided amputation, the claim against the Trust must fail. It followed that the contribution proceedings must also fail.

In fact, the parties agreed before the Court of Appeal hearing that the "balance of probabilities" test was the right one.

The Court of Appeal therefore made no ruling on that point but took the view that there was sufficient evidence to conclude, on the balance of probabilities, that, had the claimant been properly advised, she would not have proceeded with the amputation.

Affirmation of General Principle

The usual test for assessing causation in cases of clinical negligence was established in Hotson v East Berkshire Area Health Authority 2 . In that case a 13 year old boy fell out of a tree and suffered a hip fracture. Despite attendance at hospital the same day, the fracture was neither diagnosed nor treated for five days. He developed avascular necrosis.

The evidence was that, even if diagnosed and treated correctly, the claimant would still have had a 75% chance of developing avascular necrosis. At first instance, the trial judge awarded the claimant 25% of the claim, reflecting the lost chance of full recovery. The House of Lords rejected that approach and held that the correct test was whether or not the claimant could show, on the balance of probabilities, that the defendant’s negligence caused or materially contributed to the injury. In Hotson therefore, the entire claim failed, 25% being less than the required 51%.

Applying this test to the Webb case: to succeed against the Trust Mrs Webb needed to show, on the balance of probabilities, that if properly advised she would not have had the amputation. The Court of Appeal found sufficient indirect evidence to infer that she would have established her case.

Extension of Principle – Illusory or Real?

Rougier J was clearly concerned by his perceived inability to find for the claimant on causation on conventional grounds. To circumvent this, he appears to have utilised Lord McKay’s comments in Hotson that it would be unwise to rule that a claimant could never succeed by proving "loss of a chance" in a medical negligence case.

Given Rougier J’s approach and cases in which the "loss of a chance" approach has been used, the possibility of extending the categories of cases applying a "loss of a chance" test arises. However, on closer inspection, it is only the "second" element of causation that involves any valuation of a lost chance.

Loss of a Chance - a Separate Category?

It is well-established law3 that, where a solicitor is sued for failing to process a claim, the court will award damages proportionate to the chance of success of the original action. Claimants must demonstrate that they have lost a real chance of a benefit4 .

Is there any real distinction between these cases and any other? Arguably, there is not. In analysing causation in all cases the court performs two distinct exercises. The first is the application of the "but for" test: but for the defendant’s negligence would the claimant’s position have been any better?

If the claimant can overcome the first hurdle, the court must then determine the extent of the damage directly attributable to the defendant’s negligence. In appropriate cases, it is this aspect that is susceptible to determination by reference to "loss of a chance".

It is not only failed litigation cases that are appropriate to such assessment. In Doyle v Wallace5 the Court of Appeal upheld a ‘loss of chance’ assessment of the claimant’s loss of earnings claim in a personal injury action, bringing the possibility much closer to clinical negligence claims.

Possible Benefit

What is sauce for the gander, as it is said, is sauce for the goose and, in this context, the cases of Clark v MacLennan6 , and Judge v Huntingdon Health Authority 7 warrant examination.

In Clark the defendants performed an operation prematurely. The evidence was that an operation at the correct time would have given the claimant a two in three chance of avoiding injury. The judge awarded two thirds of the total damages.

On the face of it, Clark appears to be a "loss of chance" case. It can, however, be explained by reference to the "traditional" approach. The claimant had established, on the balance of probabilities, that but for the defendant’s negligence she would have avoided injury. However, in assessing the extent of the injury, the court discounted the damages to reflect the risk of failure.

In Judge, the court found that timely diagnosis and treatment of breast cancer would have given the claimant an 80% chance of a cure. The court then went on to award 80% of the total damages. The only logical explanation for this conclusion is that the court determined that, on the balance of probabilities, the claimant would have been cured, but then took into account the 20% risk that the claimant would not have been cured even if she had been diagnosed and treated properly.


The difficulty at first instance in the Webb case was that Rougier J got it wrong. He endeavoured to apply a "loss of a chance" to the first stage of his causation assessment, rather than to the second.

It might be thought that as the Court of Appeal have confirmed the Hotson test, clarity will now prevail. It remains the case, however, that once a claimant has established that proper treatment/advice would have benefited him to some extent, then in appropriate cases (which appear to be those in which a purely hypothetical analysis is required), "loss of a chance" may peer around the door, reducing the overall recovery.

1 (16 July 2001)

2 [1987] A.C. 750

3 See Kitchen v Royal Air Forces Association[1958] 1WLR 563(CA)

4 Allied Maples v Simmons & Simmons [1995] 1WLR 1602

5 (The Times) 22nd July 1998

6 [1983] 1ALL ER 416

7 [1995] 6 MED LR 223

The content of this article does not constitute legal advice and should not be relied on in that way. Specific advice should be sought about your specific circumstances.

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