Causation
- Elliot Tierney
- Jul 27, 2023
- 5 min read
Updated: Jul 31, 2023
To establish causation, the claimant has to show that their loss is sufficiently connected with the defendant’s breach of duty.
Factual Causation:
Factual causation questions whether there is any connection between the defendant’s breach and the claimant’s loss in fact. The defendant’s breach must be a factor in causing the claimant’s loss for there to be a valid claim.
‘But for’ Test (Orthodox Approach / Usually Used):
The 'but for' test establishes whether the claimant would have suffered the loss but for the defendant’s breach.
In Barnett v Chelsea & Kensington Hospital, B drank tea that had arsenic in it. Upon feeling unwell, he went to the hospital. They told him to go home, where he later died. B’s estate claims against the hospital. ‘But for’ B being sent home by the hospital and being incorrectly diagnosed, B would still have died due to the amount of arsenic he had consumed. The court held that the hospital was not liable.
Multiple Causes:
Where there are multiple causes to the claimant’s loss, the defendant’s breach merely has to be a factor. Therefore, causation cannot be disproved by proving another cause.
Divisible Injuries:
Where the defendant’s breach has caused some, but not all, of the claimant’s loss, there is a dividable injury.
In Jobling v AD, J slipped at work and injured his back. The employer (AD) accepted the workplace was unsafe and J sues for loss of earnings. J is later diagnosed with an independent congenital back problem, so AD’s breach did not cause all of J’s loss (would’ve had to stop work anyway). ‘But for’ AD’s negligence, J would have still been working until his back problem incapacitated him. AD held to be only liable to pay for the loss of earnings between the time that J slipped and when he would’ve become incapacitated anyway.
Proof:
Often it is uncertain whether the claimant would’ve suffered their loss had the defendant taken reasonable care. The burden of proof on the claimant to show that their loss was more than likely caused by the defendant’s breach.
In Wilsher v Essex AHA, W is born prematurely and poorly. E place a catheter in the incorrect place and therefore read the wrong oxygen levels. On these readings, they give W too much oxygen. W suffers damage to eyesight. Medical knowledge shows that excess oxygen can cause loss of eyesight, but it was not more than likely the cause (due to other independent reasons). The HL reject W's claim.
This burden can lead to undesirable outcomes, hence why the courts sometimes differ from the ‘but for’ approach.
Departing from ‘But for’ Test (Exceptional Circumstances):
Sometimes the result from the ‘but for’ test provides intuitively incorrect results, which would lead to injustice. Therefore, the court may depart from this test in exceptional circumstances.
Example of where ‘But for’ Test is Incorrect:
C goes on a trek across a desert. D1 poisons the water while D2 drills a hole in the bottle so its contents leak out. Both D1 and D2 act independently of one another. C dies as a result.
If the ‘but for’ test is applied, it says that C would’ve still died despite D2’s actions, so they are not liable. It would also say that C would’ve still dies despite D1 poisoning the water, so they wouldn’t be liable either. It is common sense that neither of these provide a desirable decision.
Situations where ‘But for’ Test can be Departed From:
Overall, it is quite unclear when these exceptions apply.
Material Contribution to Risk of Injury:
The defendant's material contribution to the risk of injury may be a sufficient causal connection to the injury that the defendant is liable.
In McGhee v NCB, a miner (M) suffered dermatitis (skin irritation). Evidence suggested this was caused from the brick dust in the air while mining. While it is unavoidable to be covered in the dust because of the nature of his work, M claims NCB was negligent in not providing M with washing facilities. C cannot prove that ‘but for’ the extra exposure he wouldn’t have dermatitis. The HL still hold NCB liable.
Mesothelioma Cases:
In Fairchild v Glenhaven, a group of Cs contracted mesothelioma (cancer caused by asbestos exposure) and sue their employers who exposed them to asbestos. C could not prove the employer was the ‘but for’ cause on the balance of probabilities.
Each D was liable - merely contributing to the risk was enough to hold D liable. Decided on the basis of the unfairness of denying C’s claim would be more detrimental than the unfairness to D for holding them liable and, without the exception, the duty to not expose people to asbestos would be undermined and C would never have a claim.
In Barker v Corus, (fact pattern follows Fairchild) B had a period of self-employment where they were exposed to asbestos.
The HL widens the exception to include cases where there is an ‘innocent’ cause of injury (moving away from Wilsher) but narrows liability of D to the proportion of the exposure that they are responsible for.
Parliament specifically target the judgement of Barker. The claimant is entitled to full damages from each defendant in mesothelioma cases. [1]
In Sienkiewicz v Greif, S contracts mesothelioma. S could’ve contracted it from environmental exposure (24 cases per million) or G’s breach during employment (28.39 cases per million). The SC hold that G merely has to increase chances of contracting mesothelioma to be liable. Court reaffirm this approach is limited to mesothelioma cases.
Material Contribution to the Actual Injury:
Normally, contribution to an injury establishes causation. If it can be established that the defendant’s actions contributed to the state of affairs, the defendant’s particular breach is irrelevant.
In Williams v Bermuda Hospitals, W does to hospital (BH) with appendicitis. BH’s doctors fail to correctly diagnose him. W’s appendix burst, he gets an infection and later sepsis. W claims BH was negligent in finding the correct diagnosis. Question of whether the failure to diagnose caused the sepsis as W’s appendix would’ve burst regardless.
The PC establish causation as BH’s negligence contributed to W’s harm by making him suffer for longer than usual / longer than he should have. Therefore, BH had materially contributed to W’s injury.
In Hotson v East Berks AHA, H was misdiagnosed in hospital. He had a 25% change of avoiding injury if D had taken reasonable steps. As the ‘but for’ test would’ve shown that it was more likely that H would not be injured.
The HL hold that causation of injury is not proved on the balance of probabilities but that he had lost the chance of avoiding the injury. EBAHA liable.
Lost Chances (for Physical Losses):
The chance of avoiding physical harm is not a recoverable loss.
In Gregg v Scott, S had misdiagnosed G’s cancer. As a result, G’s treatment was delayed for 9 months, reducing his chance of surviving 10 years from 42% to 25%. The HL dismissed G’s claim.
Justification:
Complexities of proof when determining precise chance of loss. More evidence required than in ‘but for’ test.
Proliferation of claims.
Fiction / Misreading of statistics: A 25% chance of recovery does not mean that everyone has a 1 in 4 chance of fully recovering, but that 1 person has a 100% chance of recovery while the remaining 3 have 0% chance in a group of 4. Courts cannot split people into these groups.
Legal Causation / Remoteness:
Legal causation concerns whether the connection between the defendant’s breach and the claimant’s loss is enough to justify holding the defendant liable for that loss.
See Remoteness Lecture Notes.
This doctrine is generally more normative / policy concern orientated.
Resources:
References:
[1] Compensation Act 2006 s3(2)
Cases Mentioned:
Barnett v Chelsea & Kensington Hospital Management Committee [1968] 2 WLR 422
Jobling v Associated Dairies Ltd [1982] AC 794
Willsher v Essex Area Health Authority [1988] 1 AC 1074
McGhee v National Coal Board [1972] UKHL 7, 1 W.L.R. 1
Fairchild v Glenhaven Funeral Services Ltd [2002] UKHL 22, [2003] 1 AC 32
Barker v Corus plc [2006] UKHL 20, [206] 2 AC 572
Sienkiewicz v Greif (UK) Ltd [2011] UKSC 10, [2011] 2 AC 229
Williams v Bermuda Hospitals Board [2016] UKPC 4
Hotson v East Berkshire Area Health Authority [1987] AC 750
Gregg v Scott [2005] UKHL 2, [2005] 2 AC 176
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