CNZ (Suing by her father and litigation friend MNZ) v Royal Bath Hospitals NHS Foundation Trust (1) and The Secretary of State for Health and Social Care (2)

John-Paul Swoboda discusses this recent case, which relates to events in 1996, and involves consideration of whether Montgomery applies to such historic circumstances.

Lying below each number in this judgment lies a significant story. CNZ who suffered severe injury at birth was 26 years old at the date judgment was handed down. The issues were so numerous and complex in this liability only trial that it took 107 pages and 407 paragraphs for Mr Justice Ritchie, a hugely experienced clinical negligence specialist, to determine them. As the circumstances giving rise to this claim took place in 1996 it was necessary to consider whether Montgomery applied at all. On the judge’s primary findings in respect of causation all injury would have been avoided with just 30 seconds to spare (CNZ was successful in her claim relating to intrapartum negligence but unsuccessful in her claim that caesarean section ought to have been discussed, and agreed upon, during the ante-natal period). On the judge’s findings in the alternative 100% of the damages should be recovered because, even if not all injury was caused by the negligence, it was impossible to determine the Claimant’s functional outcome but for the negligence.    

The two numbers from this judgment analysed below are 1996 and 100%: Montgomery and its application in 1996; and 100% recovery of damages on Ritchie J’s findings in the alternative.

Does Montgomery apply to decisions made in 1996?

Judicial precedent modifies the common law by clarifying what the law is and by correcting any error of law that has occurred. The common law is different to statute in that statute rarely has retrospective effect whereas modifications to the common law do. The retrospectivity of changes to the common law is highlighted in Practice Statement (HL: Judicial Precedent) 1 W.L.R. 1234, which reminds us of “the danger of disturbing retrospectively the basis on which contracts, settlements of property and fiscal arrangements have been entered into and also the especial need for certainty as to the criminal law.”  

As judicial precedent does have retrospective effect, then Montgomery, on the face of it, affects decisions relating to disclosure of risk and informed consent not just also after the judgment but also historic decisions.

What happens however where the reasoning for the decision (or part of the reasoning) arises because of temporal factor: in the context of Montgomery the move from paternalism to patient choice was said to be necessitated by greater access to information by access to the internet and changes in societal values embodied in the Human Rights Act 1998. The ratio decidendi of a judicial decision is the general reasoning given for that decision and where there is more than one reason given for a decision all the reasons form part of the ratio (cf. Jacobs v LCC [1950] AC 361[1950] 1 All ER 737, HL). So, in a case which predated the societal changes and availability of information which underpinned the decision in Montgomery, the ratio from Montgomery would, as a matter of logic, not apply. That must be why Ritchie J (correctly in my opinion) doubted whether the ratio from Montgomery would apply to cases concerning decisions made in the 1950’s or 1960’s.

But what about a case where the events occurred in 1996, in the early days of the internet and before the passage of the Human Rights Act? When considering that question it is right to remember the events which gave rise to Montgomery happened in 1999, just three years later than the events in CNZ. Were those three years sufficient for Ritchie J to apply “a watered-down form” or “a tapered” approach to Montgomery? Ritchie J thought that might be the correct approach but did not feel he was permitted, as a first instance judge, to take such an approach “without an indication” from the Supreme Court. This is a tantalising conclusion as it suggests that Ritchie J actually wanted to use a “watered down” version of Montgomery (perhaps closer on the spectrum to Bolam and paternalism).

Had Ritchie J taken such an approach would it have made a difference to this case? It may have done. Some of the findings of breach of duty were based upon either “failure to provide [the mother] with appropriate treatment options” or “failure to listen to and agree to [the mother’s] choice of CS” which is to say consent issues. However, other findings were based on “negligent delay”, which is not an issue of informed consent, or disclosure of risk.  It is difficult to disentangle what delay was attributable to consent issues and what delay to Bolam issues. However, given 30 seconds less of negligent delay would, on the findings of Ritchie J to change the position on causation it seems likely, in my opinion, that had a “watered down” version of Montgomery been adopted, closer on the spectrum to Bolam, that it could have made a difference to the outcome.

Is it plausible that with a “watered down” version of Montgomery the findings on consent would be reversed? Yes. In Montgomery the Supreme Court referred to how the need for disclosure of risk and informed consent had long been recognised by the medical profession’s internal standard setting body, the GMC. There was reference to 2013 guidance, 2008 guidance and critically for a case centred around events in 1999, a guidance from 1998. The facts of this case predate the 1998 GMC guidance, the Human Rights Act, and was also at a time when the internet was in its infancy. The factors in support of patient choice were absent or at least less obvious. Or to put it another way, the societal change which underpinned the move from paternalism to patient choice had not happened or at least not been completed.

Is cerebral palsy a divisible condition which ought to be subject to apportionment?

As Ritchie J eloquently set out there is a significant difference between cancer cases and cases where the severity of the injury is linked to the duration of the insult. The paradigm examples arise from asbestos litigation: mesothelioma is a cancer where the severity of the condition is divorced from quantity of asbestos fibres inhaled; asbestosis is a form of fibrosis of the lung where the severity of the fibrosis (and consequent respiratory deficit) is linked to the extent of the fibres inhaled[1].

Cerebral palsy was caused by profound hypoxic injury with the experts’ evidence in CNZ being that, roughly speaking, the longer the PHI the more severe the brain injury and cerebral palsy. Ritchie J accepted that brain injury in this context is not akin to mesothelioma. As such it may be termed a divisible injury.

In divisible injury cases such as asbestosis, or hearing loss etc. it has been said that if, “a substantial part of the impairment took place before the defendants were in breach, why in fairness should they be made to pay for it? The fact that precise quantification is impossible should not alter the position. … What justice does demand, to my mind, is that the court should make the best estimate which it can, in the light of the evidence, making the fullest allowances in favour of the plaintiffs for the uncertainties known to be involved in any apportionment. In the end, notwithstanding all the care lavished on it by the scientists and by counsel I believe that this has to be regarded as a jury question, and I propose to approach it as such.”  (cf. Mustill J Thomson v Smiths [1984] Q.B. 405).

Ritchie J accepted the above as an accurate statement of law for a divisible injury, subject to a comment that a broad-brush approach is not as relevant where the damages award is very large. The finding that the size of the award affects the suitability of a broad-brush award is, in my opinion, open to question: the importance of the litigation is normally greater where the award is larger, but can it really be said that a broad-brush approach to causation is proportionally any less fair (to either claimant or defendant) dependent upon the size of the award.

The critical question on apportionment was, as Ritchie J, identified one of evidence: was there a fair evidential basis for apportionment or was apportionment in this case impossible. Ritchie J found if apportionment was really impossible then 100% of damages were recoverable. Dr Rosenbloom, consultant paediatric neurologist for the defendant, suggested that damage could be apportioned but only in 5-minute chunks after the first 10 minutes of PHI (which was decided does not to cause permanent brain injury). Ritchie J found that that theory fell apart on logical analysis because if the negligence did not take the new-born into a different 5-minute aliquot there could be no damages (though such an approach applies Rosenbloom’s theory with a rigidity not required by the court). He also considered a differentiation between mild, moderate and severe brain damages did not assist with quantification as the quantification experts would need to understand better how the counter-factual would have looked. Finally, he found that there was not sufficient data to support Doctor Rosenbloom’s theory.

Ritchie J found it was truly impossible to differentiate the negligent from the non-negligent damage and as such damages for the totality of injury were recoverable. That conclusion may legitimately be questioned: the court can treat damage as a jury question (see Thomson above); the court can approach causation with a broad-brush (as it did in Rahman v Arearose [2001] Q.B. 351 (CA). The absence of robust data to back a scientific theory need not prevent a court taking a pragmatic approach to apportionment and assessment of damages.


This is unlikely to be the end of the story for CNZ as permission to appeal has been sought by the Defendant and indeed permission was granted on one ground (in respect of apportionment) by Ritchie J.

The number to finish this blog on is 4. CNZ suffered from quadriplegic cerebral palsy, affecting all 4 limbs, and she required a litigation friend meaning she did not have capacity to litigate. CNZ has suffered terribly. That suffering was, on the findings of the Court, wholly or at least in part due to negligence. That human story ought not to be forgotten in technical legal argument.  

[1] There is in fact some debate on this issue but the above represents the current position in law.

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