The High Court applied material contribution causation principles to a case where distress over a delay in an ambulance arriving led the Claimant to develop Post-Traumatic Stress Disorder (“PTSD”).
The Claimant suffered a sub-arachnoid haemorrhage due to a ruptured aneurysm. Her initial call for an ambulance was timed at 14:22 hrs, but the ambulance did not arrive until 16:11 hrs – 1 hour and 49 minutes later. The judge expressed “surprise” at that time period, although the parties agreed that the claim was to be determined on the basis of a period of negligent delay which had been admitted by the Trust: that period was 31 minutes.
With hospital treatment the Claimant made a good physical recovery. However, she also developed PTSD, which manifested in severe anxiety. The question for the court was whether the PTSD was caused or contributed to by the admitted breach of duty i.e. the 31-minute delay. In that regard, the evidence was clear that the haemorrhage itself was distressing, and any period of waiting for help was frightening. The Claimant was at home alone at the time, and experienced symptoms such as severe pain, vomiting, and repeated loss of consciousness.
The judge applied the causation principles articulated by Waller J in the case of Bailey v Ministry of Defence  EWCA Civ 883 (see in particular  of that judgment) and transposed them into the case before him as follows:
- If it can be shown that the claimant would have developed PTSD, in any event, irrespective of the negligent period of delay, then the claim fails;
- If it can be shown that but for the period of negligent delay the claimant would not have developed PTSD, then the claim succeeds;
- If, on the other hand, the evidence is incapable of supporting either of the two propositions set out above, then if it can be shown that the negligent period of delay has made a material contribution to the PTSD, the claim succeeds.
In assessing the matter, the judge preferred the evidence of Claimant’s expert, observing that the Defendant’s expert had expressed a number of unfair criticisms of the Claimant, that he had cited statistics without providing the source material, and that he had seemed to change his opinion during his oral evidence as to whether PTSD was triggered by the haemorrhage itself, or some point subsequently but before the period of negligent delay.
Perhaps more importantly, the judge made some more general comments about PTSD, which will assist Claimants in what is likely to be a very common kind of claim.
First, he emphasised that, just because PTSD could have been triggered by a shorter period of trauma, it did not necessarily follow that it could not be said that a longer period made a material contribution to PTSD, and he felt that it would be speculative to attempt to identify a trigger point. At  he said:
“…Undoubtedly, what occurred prior to the negligent period of delay was traumatic and, in particular, the fact that the claimant felt that she was going to die; and that she was suffering intense physical pain. Nonetheless, it does not follow that it is possible to identify a specific cut-off point when it could be said that whatever happened thereafter, PTSD was going to evolve. To the contrary, it seems to me that to look at the matter in that way is to adopt an artificial approach. It is, to my mind, in the realms of speculation to attempt to identify a fixed time when the claimant had suffered sufficient trauma such that she was likely to go on to suffer PTSD. Accordingly, I think there is considerable force in the proposition advanced by Dr Smith to the effect that medical science is not capable of dissecting that 31-minute period from the rest of the period of delay, so as to enable the inference to be drawn that PTSD would have occurred irrespective of the 31-minute delay.”
It is of note that he described the exercise of identifying a PTSD trigger-point as an artificial approach, rather than reaching a view solely based on the substantive evidence presented in the particular case – that could cause some consternation for Defendants.
Secondly, he declined to make any apportionment between the negligent and non-negligent periods of waiting for the ambulance, because he considered PTSD to be an indivisible injury. At  he said:
“ …I have already observed in the course of this judgment that I regard PTSD as an indivisible injury. It is far removed from, for example, industrial diseases such as noise induced deafness or asbestosis which are known to be dose related. That is simply not the case with PTSD. If I cannot say when the trigger for the PTSD occurred, it would not be logical to go on to conclude that, nevertheless, there can be an apportionment exercise. In any event, such would not be legitimate if my assessment is correct that this is an indivisible injury.”
Although the point that apportionment would not be possible in circumstances where he was not able to say when the PTSD was triggered is cogent, his identification of PTSD as an indivisible injury implicitly discounts the possibility of arguing, on different facts, that PTSD could be exacerbated by a particular period of delay. It will be interesting to see if that approach continues to find favour.
In any event, in this claim, the Claimant succeeded on the basis that the negligent period of delay materially contributed to her developing PTSD, and the judge was not able to make any apportionment, so she recovered damages in full.