Proving a clinical negligence claim: the role of causation
In order to prove a successful clinical negligence claim, the person who is bringing the claim is required to satisfy a two-stage test for breach of duty and causation.
The first thing the claimant needs to show is that the medical or dental treatment they received fell below a standard that a reasonable body of medical opinion would find acceptable. This is the test to establish breach of duty, as set out in Bolam v Friern Hospital Management Committee  and subsequently modified and interpreted in Bolitho v City and Hackney Health Authority  and other cases.
Breach of duty
The second part of the test is for causation: the claimant has to establish that ‘but for’ the breach of duty, the damage or injury would not have occurred: this article will focus on this second stage of the test.
Traditionally, the test for clinical negligence has as always involved the ‘but for’ principle: for example, ‘but for’ the swabs being left in during an operation, the claimant would not have required additional surgery.
However, the complex nature of medical treatment means that it is not always easy to apply this test. The courts have been considering the standard tests for many years in relation to this difficulty and have clarified that, in certain circumstances and under certain conditions, they are willing to apply a modified ‘but for’ test. These circumstances include issues of ‘material contribution’ and where there are multiple causes giving rise to a compound injury.
The issue of material contribution has been ruled on a number of times in the higher courts over many years. It has mainly centred on cases where the injury could have been caused by both negligent and non-negligent acts or omissions. For instance, in the case of Bailey v Ministry of Defence , the claimant choked on her own vomit, causing brain damage, after a failed procedure to remove a gallstone. She also developed pancreatitis following the failed removal. The court found that the claimant was unable to clear her own airways as a result of inappropriate care (i.e. negligence) and the onset of pancreatitis (ruled as non-negligent).
In this case, had the ‘but for’ test been strictly applied, the claim would have failed on the basis that the claimant’s representatives would have been unable to prove it was the negligent act that caused the choking and subsequent brain damage.
However in Bailey (as in previous cases), the courts considered the issue of material contribution. It was clear in this case that medical science would be unable to put a percentage value on how much each of the acts contributed to the injury. However, they ruled on the basis that, even though it was impossible to establish probability, providing it could be found that the inappropriate care was “more than negligible” in contributing to the injury, then the test would be satisfied. In these circumstances, the claimant would be in a position to recover full damages.
The conclusion, therefore, is that consideration would be given to all negligent and non-negligent causes of any injury; if it were found that the negligent causes were more than negligible in contributing to the damage, then the modified test could be used.
As with the case of material contribution, there have also been many cases that have considered multiple causes and the issue of causation. One case that was recently in the courts, Wright v Cambridge Medical Group , involved a young child who suffered septic arthritis in her hip (which would eventually lead to lifelong mobility problems) as a result of a failure to refer from her GP and the negligent treatment by a hospital.
The GP surgery argued that, given the child’s previous experience with the hospital, it would have still treated her negligently, even if she had been referred a few days before. The court said that the assumption in advance should always be that any treatment will be appropriate, even if it is found to not be the case at a later date and every incident should be addressed in turn on the basis that all subsequent treatment will be appropriate. The court also ruled that, as a result of the GP’s delay, the child lost the opportunity to be treated as she should have been, in a non-negligent way, and found that causation had been met, with judgment going against the surgery.
The case of Wright illustrates that the court is happy to apportion responsibility between multiple parties when there are multiple causes, as long as the claimant can satisfy that each party provided treatment that amounted to a breach of duty.
‘But for’ test
While the traditional application of the ‘but for’ test is always preferable in clinical negligence matters, there are circumstances where the test can be modified. It is therefore vital that each claim is thoroughly investigated to determine the correct defendants and any competing factors that could have resulted in the injury. However, it must always be remembered that clinical negligence is very difficult to prove in any event and modification of the causation test will not necessarily mean that the claim will be successful or that it is necessarily for the benefit of the claimant.
If you think that you may have a medical negligence claim and need advice, please speak to a member of our specialist Clinical Negligence team on 0117 904 6000.
Posted on Aug 23rd, 2012 by Lyons Davidson