Consecutive causes
Date: 12 June 2009
Authors: Kenneth Warner
Issue: Vol 159, Issue 7373
Categories: Features, Personal injury
In Bailey v Ministry of Defence [2009] 1 WLR 1052, [2008] All ER (D) 382 (Jul) the plaintiff had been admitted on 9 January 2001 to the Royal Haslar hospital, for which the defendants were responsible, for medical procedure to deal with a suspected gallstone in her bile duct. Following the procedure her condition began to deteriorate rapidly and dramatically, and despite a number of further interventions, her condition became critical.
On 14 January she was moved to Queen Alexandra hospital where urgent surgery was performed and other treatment administered. Her condition then improved through the next two weeks to a point where she was safe, but severely weakened, and it was established that she had developed pancreatitis.
Late in the night of 26 January, while unattended, the plaintiff vomited. Due to her condition of extreme weakness she was unable to expel the vomit as a person normally would, and the aspirated vomit caused her cardiac arrest. She was resuscitated but left with permanent brain damage.
The plaintiff’s case in negligence against the first hospital was that had proper professional diagnosis and care been there provided, she would not, whilst in the second hospital, been in such a poor physical condition that she could not evacuate the vomit.
The immediate cause of Miss Bailey’s heart failure and consequent brain damage was her natural response in vomiting due to nausea, and her physical inability to cope with the vomit, not any negligent failures on the part of the first, defendant, hospital, in terms of the surgery and other treatment they had provided prior to her transfer. In law, then, was there the necessary causal link between the defendant’s negligence and the plaintiff’s damage? That is the crucial issue in the case and unless the plaintiff can, on a balance of probabilities, establish this, then despite the negligence of the defendant, which was ultimately conceded, the action must fail.
Causation
The normal and common approach taken in a case where the causal link between the defendant’s conduct and the plaintiff’s harm is in doubt is to ask the question would that harm have eventuated but for the defendant’s acts or omissions. If the plaintiff’s damage would have occurred anyway, the law, in effect, dismisses the defendant’s negligence as irrelevant. In Barnett v Chelsea & Kensington Hospital [1969] 1 QB 428, [1968] 1 All ER 1068 the plaintiff had attended the defendant’s casualty ward complaining of severe stomach pain and nausea. He was sent away without any proper investigation and he died soon afterwards.
The direct cause of death was poisoning by arsenic which he had unknowingly consumed previously at his workplace. The defendants admitted negligence in terms of the attending doctor’s failure to make any attempt at diagnosis, but, on the medical evidence, Mr Barnett’s condition was so advanced by the time he arrived at hospital that not even prompt and competent medical attention could have saved him. It was more likely than not that he would have died anyway. His action failed for want of proof of causation.
In the medical context the “but for” approach has been applied more recently by the House of Lords in Hotson v E Berkshire Health Authority [1987] AC 750, [1987] 2 All ER 909, and Wilsher v Essex Health Authority [1988] AC 1074, [1988] 1 All ER 871. In Hotson the plaintiff was a young boy who had fallen whilst climbing a tree and sustained an acute fracture to his thigh. He was admitted to hospital but his condition went undiagnosed for five days, by which time he had developed a further condition, a disability in the hip joint, due to a failure of its blood supply.
The trial judge found that even with proper diagnosis and treatment there was a 75% chance that this condition, avacular necrosis, would have occurred anyway. On the basis of that finding the House held that the plaintiff’s action failed on the issue of causation.
In Wilsher the plaintiff was a baby born prematurely and administered oxygen, which is usual procedure, but was given an excessive amount. Soon after the baby was found to be blind. The overdose of oxygen could have caused this, but on the evidence so could four other distinct conditions which can afflict premature babies, which are unconnected with that, and which in themselves do not connote any negligence on the hospital’s part. Again the action failed for want of a causal link.
The onus of proof of causation lies on the plaintiff. In Dobson v North Tyneside Health Authority [1997] 1 WLR 596, [1996] 4 All ER 474, the plaintiff had collapsed at work and was taken to local hospitals where some tests were carried out, but no CT scan. She was discharged and a few weeks later she became very ill and was admitted to Royal Victoria Hospital where the CT scan was performed and revealed two brain tumours. She was scheduled for surgery but died a few hours earlier.
Representatives of her estate wished to pursue a negligence action over the failure of the former hospitals to administer the scan, but perceived a causation issue. The scan, performed earlier, would have indicated the presence of tumours, and she would not have died prior to surgery. But the tumours could have been benign, or they could have been malignant. In the latter case she probably would have died anyway.
The only way to establish this was with an examination of the brain, or with a report as to its condition. The brain had been removed during the post-mortem examination and no longer existed, and the coroner’s report contained no finding on the matter. The absence of this evidence was fatal to the plaintiff’s claim.
In Bailey was it the earlier lack of care at the defendant hospital which was responsible for Miss Bailey’s critically weakened state, or would the pancreatitis, which would have developed anyway, alone be sufficient to induce that? We simply do not know; the medical evidence was incapable of establishing it one way or the other. On the conventional “but for” approach to causation, then, as with Dobson, the plaintiff’s action must fail.
An alternative approach
In certain types of situation, however, case law provides an alternative to the “but for” approach, more favourable to the plaintiff, requiring as it does, no more than proof that the negligent conduct of the defendant provided a “material contribution” to the plaintiff’s harm. So what is a “material contribution”, and how do we recognise the type of case in which the inquiry for a “material contribution” properly displaces the question as to “but for”?
The seminal decision is that of the House of Lords in Bonnington Castings v Wardlaw [1956] AC 613, [1956] 1 All ER 615.
During his work for the defendants over a period of years the plaintiff was subjected to the inhalation of minute particles of silica. These progressively accumulated in his lungs, ultimately resulting in pneumoconiosis. There were two sources of the silica dust, one for which the defendants could be held legally responsible, and the other which in that sense was “innocent”. But this was not a case of competing causes.
As Lord Reid observed at 621, it was pointless to seek to know which particles had caused the defendant’s harm, since all the particles were potentially lethal. In their Lordships’ view, the correct question was whether the “defendant’s particles” had provided a material contribution to the plaintiff’s condition by exaggerating the risk that it could occur. In the case of such cumulative causes, then, as opposed to competing alternative causes, the plaintiff is put to this, much less demanding, degree of proof. Evidence of the material contribution will be sufficient to establish the causal link.
The approach in Bonnington Castings was applied again by the House of Lords in McGhee v National Coal Board [1973] 1 WLR 1, [1972] 3 All ER 1008. In the course of his work for the defendants, over a few days the plaintiff had been cleaning inside brick kilns in hot and dusty conditions, and brick dust had adhered to his skin which culminated in his dermatitis.
The kilns themselves simply were hot and dusty and there was no negligence in connection with their condition. The employer’s breach lay in the failure to provide washing facilities at the work site, which the plaintiff would have utilised, hence removing the brick dust prior to leaving. That was the neglect that had materially contributed to the plaintiff’s harm by increasing the risk that dermatitis would occur, and it was a sufficient cause, in their lordships’ view, to found liability in the defendants.
Returning then, to Bailey, the trial judge had found that the critically weak condition to which the plaintiff succumbed at the time of her death on 26 January was the product of two factors, closely interlinked. One was the pancreatitis. The other was the consequence of the negligent failures of the defendants during the period 11–12 January when she was in their care. The Court of Appeal upheld the judge’s finding that she had not recovered from the effects of the second of these by 26 January, that this was sufficient to establish a causal link as a material contribution, and that therefore the plaintiff was entitled to succeed.
The Court of Appeal distinguished Hotson and Wilsher. In Hotson the House of Lords had held that the cause of the boy’s damage, the permanently injured hip, was the fall from the tree. This was not due to any negligence on the defendant’s part; it was a distinct cause. In Wilsher it was simply not possible to establish what the cause of the baby’s blindness was.
Again, this is not a case in which the conduct of the defendant is such as to exaggerate the risk of the plaintiff’s harm occurring so as to displace the “but for” approach and bring it within the ambit of “material contribution”.
In the case of consecutive causes, then, the causal link is established if the defendant is responsible for a material contribution to the plaintiff’s harm. The answer to the question as to what is “material”, considering the facts of the precedent cases, realistically cannot be clear. However the consensus of opinion appears to be that it must be something sufficient to be regarded as substantial.
Lord Reid, in Wardlaw, opined that it need only be something that surpasses the de minimis threshold. It is respectfully submitted that this is a minority view.
The Court of Appeal in Bailey expressly preferred the contrary opinion of Lord Rodger in Fairchild v Glenhaven Funeral Services [2002] 1 AC 32, [2002] All ER (D) 139 (Jun). Conceptually, “substantial” is meant to connote a level of contribution to risk which goes considerably beyond something minimal or trivial.
Kenneth Warner, senior lecturer in law, La Trobe University
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