THE DANGERS OF RELYING ON EXPERT EVIDENCE: BEWARE YE THE PARTISAN EXPERT: "UNBALANCED AND HIGHLY MISLEADING"

November 10, 2016 · by · in Civil evidence, Clinical Negligence, Credibility of experts, Expert evidence, Experts, Uncategorized

Some types of litigation are heavily reliant upon expert evidence.  Clinical negligence cases are often determined by the judge’s assessment of the experts involved.  It is disturbing to see the matters raised in  judgment today of His Honour Peter Hughes (sitting as a Judge of the High Court) in Watts -v- The Secretary of State for Health [2016] EWHC 2835 (QB).

“It is a basic duty of any expert witness, in accordance with Part 35 of the Civil Procedure Rules, to maintain independence and objectivity. Experts must not take it on themselves to promote the point of view of the party instructing them or engage in the role of an advocate”

THE CASE

The claimant was bringing an action for right brachial plexus injury which, on his case, was caused by the defendant’s negligence during delivery. Quantum was agreed at £175,000 liability was in dispute.

THE JUDGE’S ASSESSMENT OF THE CLAIMANT’S EXPERT
  1. I did hear evidence from the parties’ gynaecological and obstetrics experts, Ms Chaliha for the Claimant and Mr Tufnell for the Defendant. One thing on which they are both agreed is that if the court were to accept the mother’s evidence, multiple strong pulls, as she describes, without the use of alternative manoeuvres would have been unacceptable even in 1993[19].
  2. On a significant range of other matters, though, the experts were unable to agree. Mr Wheatley, in his closing submissions makes a number of criticisms of Mr Tufnell – for example that he inaccurately stated in his report that the protocol had been devised by Sisters Clairmont and Gleeson, and that there was an interval of some hours between the abdominal examination at 15.00 and the vaginal examination of the position if the baby’s head at 15.35 – but those criticisms are relatively minor compared with the level of criticism levelled by Mr Barnes against Ms Chaliha.
  3. In his closing submissions, Mr Barnes made a number of serious criticisms of Ms Chaliha. I quote below from his written submissions (the references are to the relevant pages of the transcript of Ms Chaliha’s evidence):
i) She undertook to provide expert evidence in respect of a shoulder dystocia in 1993 in circumstances where she had no experience of managing a shoulder dystocia until 1998 [180].

ii) She failed to supplement that knowledge by reference to any textbook other than a single textbook published in the UK, and accepted “on reflection” that she should have done more [186].

iii) She failed to give a balanced opinion in her report. For example, she felt that it was necessary to apologise for failing to recognise in her report that the policy [protocol] was reasonable [206].

iv) She was evasive and prolix in the face of difficult questions, for example her response to the issue of whether the fact that clinicians were pulling harder during difficult deliveries in 1993 was consistent with the guidance available at the time [198 – 204].

v) She made unjustified criticisms in her report, for example, in her report, at paragraph 140, she asserted that the note in the summary of labour as to the position of the foetus at delivery was unclear, but accepted in cross examination that it was clear and she should have recognised that in report, even if she doubted the accuracy [258 – 259].

vi) She made several unjustified and unexplained attempts to change her opinion in favour of the Claimant at trial:

a) She stated in cross examination for the first time that she did not accept that propulsion is a legitimate explanation for some brachial plexus injuries [210], and that although this was an issue that went to the heart of the case [211], she had not expressed that opinion before [214], despite having held it for the last six months [215], she failed to give any detailed reason for that opinion [215], and ultimately she did not stand by it [228].

b) In her report, at paragraph 132, and in the joint report at question 8, she defined a severe shoulder dystocia as one where routine forces are not sufficient to release the shoulder, and yet in evidence in chief she went further and described a severe shoulder dystocia as one in which there and been a failure of routine forces together with manoeuvres. She recognised the significance of the change in position, but was not able to give an adequate explanation for it [233 – 237].

c) In her report, at paragraph 145, she recognised that restitution occurs in shoulder dystocia, but may be less obvious. In cross examination, she asserted that restitution does not occur until the anterior shoulder is released [260]. She would not accept that she had changed her opinion, but was not able to give an adequate explanation as to why she had not set out her opinion in her report or the joint report, or provide any support for her opinion [261 – 270].

vii) She appeared not to understand the relevant anatomy. Despite accepting that where a posterior shoulder injury occurs, it occurs without the knowledge of the team managing the delivery [230], she criticised the team for not identifying it at paragraph 132 of her report and question 23 of the joint report. When this was put to her, she was not able to provide a consistent and coherent answer [238 – 244].

viii) She appeared not to understand the basics of managing shoulder dystocia. For example, she was very clear that suprapubic pressure should be applied to the pubic symphysis [246 – 247]. As explained by Mr Tufnell [287 -289], this would not be in accordance with the RCOG 2012 guidelines, which require pressure to be applied above the pubic symphysis on the anterior shoulder, and would not meet the standard necessary to pass the RCOG examinations.

  1. These are serious criticisms, but I regret to say that they are justified.
  2. I found Ms Chaliha to be a distinctly unimpressive witness, with a serious lack of knowledge of clinical practice in 1993 and a worrying lack of appreciation of the importance of basing her opinions by the standards pertaining at that time.
  3. In her report, in considering the standard of care in 1993, Ms Chaliha referred only to one textbook, an American publication, Williams Obstetrics (19th Edition 1993). Williams describes shoulder dystocia as incapable of prediction and of having potentially devastating complications. It emphasises that minimising delay in delivering the baby is of great importance to survival, and advises against over vigorous traction or rotation of the head. It goes on to detail the McRobert’s manoeuvre[20]. This appears to have been developed first in the University of Texas hospital in or about 1983 and later tested in the United States in 1989 objectively using laboratory pelvic and fetal models.
  4. In her report, basing herself solely on the one textbook, Ms Chaliha felt able to describe the manoeuvre as well recognised and described in the literature. It was central to the Claimant’s pleaded case. The Particulars of Claim specifically alleged breach of duty by failing to place the mother in the McRoberts position. Reference to it was, also, included in the parents’ witness statements.
  5. As both Ms Ashworth and Mr Tufnell (who was a Senior Registrar at the time and about to take up his first consultant’s post) said in evidence, the McRoberts manoeuvre had not been adopted in this country in 1993. Asked why she referred only to Williams, Ms Chaliha gave the astonishing answer that it was the only textbook she had readily to hand. In cross-examination:
“Q So you satisfied yourself as to the standard to be applied by reference to a single textbook from the United States?
A I was aware that there would be other textbooks that would deal with this in different ways. The one I had got hold of was just the Williams…”
  1. It is apparent from other answers she gave that she was aware of UK published textbooks, such as Dewhurst. The 5th edition published in 1995 makes no reference to the McRoberts manoeuvre. It advocates the making of a large episiotomy and the use of the lithotomy position if possible (in line with the hospital’s protocol), and emphasises that time is of the essence if the baby is to be saved and that although it describes the use of a firm attempt to rotate the fetal head, it advises against excessive rotation or traction.
  2. Another UK textbook current in 1993 was Chamberlain, Dewhurst and Harvey (2nd Edition 1986). It says:
“Immediate and vigorous management is then required. The first manoeuvre is to place the woman in the lithotomy position and perform an episiotomy if one has not already been done. The fetal head is then carried backwards towards the anus and suprapubic pressure is applied by another attendant in order to thrust the anterior shoulder into the pelvis. Although considerable force may be required, this is often successful, however overstretching the brachial plexus giving rise to an Erb’s palsy is a risk…..A brachial plexus injury will usually heal well and is clearly preferable to a stillborn child.”
  1. The approach adopted by Ms Chaliha to what was a fundamental part of her report was, in my judgment, unbalanced and highly misleading. The misfortune of such an approach is that it may provide a claimant with an unrealistic hope of success or fatally weaken what might otherwise be a valid claim had the expert’s report been thoroughly researched and presented.
  2. There are other features in Ms Chaliha’s report and evidence which appeared to demonstrate a worrying lack of understanding of some of the basic anatomical principles.
  3. During her evidence she gave a demonstration of how to apply suprapubic pressure. In so doing, she applied it not to the suprapubic area but to the pubic symphysis itself. This would have the opposite effect to what was intended. When questioned about her evidence on restitution[21], she appeared to be saying that restitution of the baby’s head did not occur in cases of shoulder dystocia, whereas in her report she had accepted that it does occur but may be less obvious. In relation to obstruction of the posterior shoulder, she appeared in her report to be critical of the team for not identifying the problem but had to admit during cross-examination that this was not possible until the anterior shoulder was delivered. I sought during cross-examination to clarify her evidence on this point:
“Q Is not Mr Tufnell right, that if the posterior shoulder obstruction had occurred before birth of the head, then the delivering midwives would not be aware of that and it would not be counter-intuitive to apply pressure if it was to release the anterior shoulder?
A Yes, my Lord, what, in that situation would happen is that the head would deliver, with downward traction, because the anterior shoulder would not be impacted because it would not be the issue.
Q But you appear to be criticising there, in a situation where it would be outside the knowledge of the delivering midwives?
A Yes. It would not be routine to look for a posterior shoulder impaction.”
  1. It is a basic duty of any expert witness, in accordance with Part 35 of the Civil Procedure Rules, to maintain independence and objectivity. Experts must not take it on themselves to promote the point of view of the party instructing them or engage in the role of an advocate. Miss Chaliha did not, in my view, properly observe that fundamental requirement. Instead she chose to ignore or play down matters that were inconvenient to her assessment of the case.
  2. A further duty owed by all expert witnesses is that if, for any reason, they change their opinion they are under a duty to inform those instructing them without delay.
  3. Essential to Ms Chaliha’s assessment of the case is that the right shoulder was the anterior shoulder and that the record made by Midwife Ridgway on delivery was wrong. If the right shoulder was posterior and the record accurate, excessive traction during the delivery of the anterior shoulder could not account for the injury.
  4. Relying on the accuracy of the record and the rapid labour, Mr. Tufnell expressed the opinion that the brachial plexus injury was the result of the pace of labour. At the time of the experts’ meeting in June 2016, Ms Chaliha did not challenge that propulsion forces can be a cause of injury to the posterior shoulder.
  5. Under cross-examination though, she said that she did not accept propulsion as a legitimate explanation. Knowing as she did the basis of Mr. Tufnell’s opinion, she was unable to explain why she had not said so before, even though she said that she had held that opinion for the last six months – i.e. it pre-dated the expert’s meeting.
  6. Mr Barnes took her to the paper published in 2008 by Draycott, Sanders, Crofts and Lloyd[22]. This provides a template for reviewing the strength of the evidence for obstetric brachial plexus injury in clinical negligence claims and considers cases of propulsion injury. The paper includes this paragraph:
“The posterior shoulder theory suggests that the injury occurs when the posterior shoulder is caught on the sacral promontory and the uterine forces continue to push the baby down the birth canal which may stretch the fetal brachial plexus. This is recognised in a recent UK medicolegal review: this (a posterior shoulder injury) is not due to any negligent action of the accoucheur, whereas an anterior shoulder injury may be due to the negligent action of the accoucheur.”
  1. When confronted with the paper, Ms Chaliha, finally, appeared to accept that maternal forces could account for permanent brachial plexus injury.
  2. This is something that is now well-recognised in the literature[23], by the Royal College of Obstetricians and Gynaecologists[24], and in decided cases[25]. The Royal College paper includes the following:
“Neonatal BPI (brachial plexus injury) is the most common cause for litigation related to shoulder dystocia and the third most litigated obstetric-related complication in the UK.
The NHSLA (NHS Litigation Authority) has reported that 46% of the injuries were associated with substandard care. However, they also emphasised that not all injuries are due to excessive traction by healthcare professionals and there is a significant body of evidence suggesting that maternal propulsive force may contribute to some of these injuries.”[26]
  1. In stark contrast to the evidence of Ms Chaliha, Mr Tufnell was clear, concise and robust both in his report and his evidence. His opinion remained consistent throughout. I have no hesitation in preferring his evidence to hers.”

AND THE RESULT?

The claimant was unsuccessful.

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