My Correspondence With Dr Dewi Evans

Peter Elston
Oct 1
61 min read

Updated: Oct 2

Last week I went to the premiere of Conviction: The Lucy Letby Case. Lead prosecution medical expert Dr Dewi Evans featured greatly, and the next day I posted on X, “Having watched the film last night, I have decided that I will be publishing my email correspondence with Dewi Evans. So many lies. And I will tag @cheshirepolice and @CPSUK. They need to know what a mistake they made hiring him. Watch this space. Lucy Letby’s case must be referred to the court of appeal.”

The day after my X post, I received an email from Dr Evans, in which he wrote, among other things, “I've just received a copy of a message you have just posted on X. I don't follow X but you seem to have got yourself into a bit of a tizz. You are proposing to publish our email correspondence. Not sure whether your "So many lies" comment applies to our correspondence or to the Ch 4 programme. As our correspondence concentrates on statistical matters, and the trial did not use statistics at any time I remain perplexed by your continued input.”

I responded, saying that I would not publish the email correspondence, per his request, at least not for the time being. He replied, “As for our previous emails, you are welcome to share them. Neither of us uses objectionable language, and if there are errors of fact involved I’ll happily correct them.”

The below is the entirety of our email correspondence between 2 Oct 2024 and last Tuesday (if it is not clear, Dr Evans is “DE” and I am “PE”). I have appended comments (in capital letters and highlighted) where I deem relevant and will continue to do so. Where a question of mine appears more than once, this is because Dr Evans provided an answer over more than one email.

My first comment is that, in relation to Dr Evans statement in his email last Tuesday, "As our correspondence concentrates on statistical matters, and the trial did not use statistics at any time I remain perplexed by your continued input”, I think it can be seen that much of the correspondence between us related to matters other than statistics.

As for Dr Evans' comment, "the trial did not use statistics at any time", not only were statistics invoked by prosecuting barrister Nicholas Johnson KC in two of the first four paragraphs of his opening statement, but the CPS in its press release following the verdicts noted that one of the four types of evidence that convicted Lucy Letby was the roster chart with its uninterrupted line of X's. This roster chart was a statistical construct, albeit a greatly flawed one. Indeed, Prof Peter Green, of the School of Mathematics at the University of Bristol and former president of the Royal Statistical Society, has said, “The spreadsheet duty roster is almost a textbook example which I would give to my students of how not to collect and present data.”

If you have a comment about anything in the below, I would be happy to consider adding it to the article. Please send to info@mephitis.co, including your credentials. This goes for Dr Evans too I should add.

PE:

I am a fellow of The Royal Statistical Society, which I hope qualifies me as an “expert” with whom you would be prepared to communicate (see screenshot of my credentials below). I hope it does. I’m also an accredited scientist, though not in a field that is relevant to the Lucy Letby case. Obviously the case is unprecedented in so many ways. What you were tasked with it seems to me was unprecedented. I have been following the case closely for two years now and it has taken up a great deal of my time and energy. The reason I started following the case then continued to follow it is that I have interests in science and the justice system. I noted it was an extraordinary case from the start and I have not been able to let go. I have what I hope are some simple questions for you, as below.

1. When you joined Operation Hummingbird in July 2017, did you have in your mind a process that you should be following in terms of making sure you avoided bias?

2. You have said something along the lines of asking the police when you first joined Operation Hummingbird for a couple of cases (you said you were given Baby O’s) in order to get an idea of the sort of thing they were looking at. Did you believe that asking for that adhered to a process that avoided bias?

3. Did you ask the police how they had selected Baby O’s case to give you to help you get an idea of the sort of thing they were looking at?

4. You were given 33 cases to appraise in July 2017, 17 deaths and 16 non-fatal collapses. It appears that the 17 deaths were all the deaths that occurred within a particular time frame, whether June 2015 to June 2016 or otherwise. Did you ask why this time frame was selected and if so did you tell them that the time frame should be expanded (to, say, five years from Aug 2012 to Jul 2017 inclusive) in order to avoid bias?

5. Given that you have said you ended up appraising 82 cases (let’s say for the sake of argument that this was 17 deaths and 65 NFCs, though you of course can correct me if it’s material), did you know the basis on which the first 16 NFCs were selected? This was only a quarter of the 65 NFCs you ended up appraising. Did you ask if the 16 you were initially given were all the NFCs that the police at that time were looking at i.e. they did not at that time have the other 49 in their sights? 16 was clearly a small proportion of the total NFCs that occurred during the period in question (I have been told by medical experts that there are many more NFCs than deaths, which of course is logical). Did you ask how the 16 NFCs were selected, in order to ensure that your review process would avoid bias?

Dr Evans, thank you in advance for any response to my questions. I suspect you have a number of conversations going at the same time, so any help you can provide me is much appreciated.

Kind regards,

Peter Elston

DE:

I hope that I am in communication with an experienced statistician who is both temperate and objective, and that both of our disciplines appreciate the benefit of respecting each other’s professional expertise. I’m afraid that has not been forthcoming from some representatives of the RSS to date, or indeed from some neonatologists, none of whom as far as I know where involved with Letby’s trial.

PE:

I do not have a CSTAT but I have a number of statistics qualifications, have a strong maths background, and have been "doing" statistics for decades, whether in relation to my profession or as a geologist. I like to think that I am both temperate and objective. I certainly believe in treating everyone with respect.

DE:

Accept this.

DE:

The recent demand of “24 experts” that the Thirlwall inquiry be postponed indicates the most incredible hubris. It was grossly disrespectful to Lady Thirlwall. It shows a gross disregard for the feelings of the families whose infants died or sustained life-changing injuries as a consequence of the action of one rogue nurse. The families have been waiting for 8 to 9 years to discover what led to the tragedies that killed their babies and caused irreversible harm to many others..

PE:

Do you have a view on why so many medics and scientists have spoken up against the verdicts? There must be 50-100 by now, many of them eminent, who have put their hard-earned reputations on the line in one way or another.

DE:

On what do they base their concerns. None were involved in the trial. Most are anonymous. So “what hard reputations_…”._ _Evidence on oath in the public domain perhaps? After getting all the facts? This is just bitching from the touchline. All heat, very little light!

PE:

I believe Mike Hall has spoken up and he was involved in the trial. As for the others, my “50-100” number was just those who have not been anonymous (there are others who have been anonymous I agree). All but one (Mike Hall) were not involved in the trial so of course their public statements were based on what has been in the public domain. Are you able to cite examples of public statements (of theirs) that are wrong and/or would have benefited from having had sight of transcripts/evidence? For example, Prof Colin Morley said on the File on 4 radio broadcast that it was clear to him that Baby C had a bowel blockage (he based this on bilious vomit/aspirates and the x-ray showing air in the upper but not the lower bowel). Why is he wrong? Also, Prof Wayne Jones has said that the test that was used at trial to prove intentional poisoning with insulin did not in fact prove that and that to prove that a mass spectrometry test should have been done but wasn’t. Again, why is he wrong?

DE:

I have reviewed Infant C’s case from the beginning. Colin Morley is correct re intestinal issues but autopsy did not show intestinal obstruction. It’s therefore probable that the baby had a “functional” intestinal problem, not uncommon in premature babies. It does not explain the baby’s collapse and death around midnight on 13/14 June. [I’ll provide more details regarding this at a later stage, but Cheshire Police have told me that the baby’s parents don’t want the case to be circulated in the public domain, which I think one must respect. Also I told the File n 4 director that I would be pleased to liaise with Colin Morley about this case, but I’ve not heard anything]. Wayne Jones’s comments are outside my brief. I am aware of comments from Prof Frayn (not known to me) saying that the tests carried out were acceptable within 5% accuracy, and that this was fine as the insulin values were so high. He adds that a ‘back up’ test would be recommended. From a clinical perspective the glucose values of the 2 infants were very much what you’d find in a baby who has received insulin inappropriately, but one could not prove that conclusively without getting the insulin and C-Peptide values. I’ve received copies of reports from an ‘anonymous’ neonatologist and have reviewed the first 9. They are dreadful and would be shredded by any half competent barrister. [I’ve been asked not to share them, unsurprisingly, which is unfortunate.]

PE:

If baby had not opened bowels since birth and had an enlarged stomach, why was it right to feed the baby? It is my understanding that this preceded his collapse. Why wouldn't this have caused the collapse?

DE:

He only received 0.5 ml of milk. Delayed bowel action is common in preterm babies. Trying out some milk is a reasonable option as it may 'stimulate' intestinal movement.

PE:

Did you consider if clinicians had examined bottom/anus to ensure that there was a functioning opening as a cause of obstruction? Was this done? How were other congenital abnormalities excluded before the result of the post mortem was known?

DE:

I can't answer this. As there was no anal blockage found at autopsy one can confirm that he did not have any anatomical obstruction anywhere within his intestinal tract.

PE:

I'm told the Countess clinicians couldn't have known that the obstruction was "functional" at the time (this was only known about at the autopsy). So why didn't they refer the baby to a surgical centre when bilious aspirates/vomiting persisted? From my understanding reading around, all babies with bilious vomiting should be discussed with surgeons for consideration of dye tests to check for malrotation of the gut. What are your thoughts about this?

DE:

I suspect surgical consultation would have been considered on Sunday or Monday. (Another baby with significant bowel obstruction was referred to Alder Hey within 12 hours - and surgery was successful - so clinicians were aware of the importance of bile. Sadly the baby was murdered by Letby before any reasonable clinician would have considered surgical referral.

PE:

Could the resuscitation have been unsuccessful due to poor skills on behalf of the team who resuscitated the baby? For example, it seems strange that they reported no heart rate but then baby lived for hours after the resuscitation.

DE:

No. Resuscitation was carried out as standard as far as I can see. Several babies were resuscitated successfully.

PE:

You changed your opinion about how baby was murdered several times in this case. It appears that you were looking at ONLY how the baby was murdered, rather than having an open mind as to why this baby may have died. Why are you so sure that murder was the only possibility here?

DE:

I did NOT change my mind 'several times'. My 2 initial reports highlighted my concerns regarding the vents up to midnight on 13 June. My reports did not allege anything. Whilst it's not possible to rule out that his collapse was the result of a massive injection of air into his stomach immediately prior to his collapse it's more likely that it was due to air injected directed into the bloodstream - as per Infants A & B (and many others)

PE:

Would you be willing to share the revised report that you submitted about how you think baby C died to the police last week?

DE:

The police have respectfully asked me not to disclose the report to others. Without being patronising the issues centre on significant clinical issues, and would be best shared with a neonatologist. If you are in touch with a neonatologist he / she is welcome to get in touch with me.

PE:

When you joined Operation Hummingbird in July 2017, did you have in your mind a process that you should be following in terms of making sure you avoided bias?

DE:

Avoiding bias was a crucial part of my remit and I proposed the following. At my first meeting with Cheshire Police (10 July 2017) I requested copies of the clinical records for all deaths and collapses from January 2015 to December 2016, and that the files should include ALL deaths and ALL collapses, not just ones that were ‘unexplained’ or ‘suspicious’. This 2 year window extended beyond the ‘peak deaths’ noted during this period. I told Cheshire Police that if they had any suspects that I did not want to know any names. For their part Cheshire Police did not disclose any information to me regarding ‘hand over’ notes found in Letby’s home and her parents’ home, WhatsApp or Facebook messages, or any of her ‘Post Its’. I heard about these just before or during the trial. I did not receive of any reports prepared previously by others. The RCPCH report was available online but was redacted. I only discovered that the complete report included references to Letby following the verdict. I have yet to see the full report. Cheshire Police did not give me a copy of Letby’s rota, not a criticism. I only received that last month (5 Sept 2024). I think it is indicative of the effort we all made to look at each case on its clinical merit, avoiding ‘fitting’ the clinical presentation to comply with Letby’s, or anyone else’s, presence on the ward. As I concentrated mainly on the clinical (medical) notes rather than the nursing entries, no nurse name ‘registered’ with me during my review of 33 notes conducted prior to Letby being named in July 2018. I have never spoken to any of the local doctors or nurses, and did not visit the unit other than a very brief visit just before the trial started. The unit had transferred to another site by then, so one gained nothing from this visit.

MY COMMENT: PER ABOVE, DR EVANS “REQUESTED COPIES OF THE CLINICAL RECORDS FOR ALL DEATHS AND COLLAPSES FROM JANUARY 2015 TO DECEMBER 2016, AND THAT THE FILES SHOULD INCLUDE ALL DEATHS AND ALL COLLAPSES, NOT JUST ONES THAT WERE ‘UNEXPLAINED’ OR ‘SUSPICIOUS’”. HE WAS GIVEN 17 DEATHS AND 16 NON-FATAL COLLAPSES TO APPRAISE, AND IN DECEMBER 2017 DECLARED THAT MANY OF THE BABIES HAD BEEN ATTACKED. WHILE THE 17 DEATHS MAY HAVE BEEN ALL THOSE THAT OCCURRED IN 2015 AND 2016 (13 “IN HOUSE” DEATHS AND 4 “TRANSFER” DEATHS) THE 16 NON-FATAL COLLAPSES WERE CHERRY PICKED BY THE COUNTESS CONSULTANTS BECAUSE THEY DEEMED THEM ‘UNEXPLAINED’ OR ‘SUSPICIOUS’. WHY WAS DR EVANS NOT GIVEN ALL THE NON-FATAL COLLAPSES TO APPRAISE PER HIS REQUEST?

Also, in relation to his statement above, "I told Cheshire Police that if they had any suspects that I did not want to know any names", Dr Evans gave this interview to BBC Wales on 22 August 2023, days after the verdicts were announced. In it he says (translation), "So, after doing that the police had 15 then 17 cases. I told the police that they had to look at the rota of which nurse and which doctor was on duty the minute this happened - because if you create an injury for a baby the baby is going to deteriorate very quickly." Then, "After looking at the first four cases, there was only one nurse on duty for the four cases, namely Lucy Letby, and she was on duty on 17 of the cases. So, for the first time we had contact between a baby deteriorating or dying, and one individual. And from then on Chester Police questioned her and got more and more evidence until the case came to court last year." This suggests that Dr Evans did in fact know the name of Lucy Letby. He also talked about needing to ascertain who was on duty at the precise time of the collapse, because a baby is "going to deteriorate very quickly" if injured. In which case Lucy Letby was on duty for 10 or 17 deaths. The probability of a nurse, the unluckiest one, being on duty for 10 of 17 deaths is very high. That nurse it seems was Lucy Letby.

PE:

What form did "Letby's rota" that you received take? In what capacity did you "receive it"?

DE:

Letby’s rota. I received it via e-mail from someone engaged with the enquiry a few weeks ago. It was prepared by Cheshire Police. I shall send you a copy when I’ve finished my calculations re Letby’s presence and all the deaths.

MY COMMENT: IT IS POSSIBLE THAT WHOEVER SENT THE DOCUMENT TO DR EVANS BREACHED LEGAL PRIVILEGE, PARTICULARLY SINCE DR EVANS WAS NOT LONGER FORMALLY INVOLVED IN THE CASE. DR EVANS LATER TOLD ME IT WAS A JOURNALIST WHO HAD SENT IT TO HIM, RATHER THAN "SOMEONE ENGAGED WITH THE ENQUIRY". BUT WHY DID A JOURNALIST HAVE IT? IT WOULD BE INTERESTING TO KNOW WHO SENT IT TO HIM.

PE:

I look forward to receiving that and would be delighted to provide any statistics expertise I can.

PE:

You have said something along the lines of asking the police when you first joined Operation Hummingbird for a couple of cases (you said you were given Baby O’s) in order to get an idea of the sort of thing they were looking at. Did you believe that asking for that adhered to a process that avoided bias?

DE:

I had requested a copy of a ‘couple of cases’ but received just the one [Infant O] at our first meeting. This was simply to give me ‘a feel’ of the clinical process at the department; quality of note keeping, input from senior doctors, autopsy result, etc.

PE:

Why do you believe that asking for a 'couple of cases' did not constitute bias? Why could you not have got this "feel" by requesting all the notes?

DE:

A ‘couple of cases’. Received just 1 actually, Baby O. How could I request all the notes when I had no idea how many cases there were?

MY COMMENT: DR EVANS HAD WRITTEN TO ME (SEE ABOVE) THAT HE HAD “REQUESTED COPIES OF THE CLINICAL RECORDS FOR ALL DEATHS AND COLLAPSES FROM JANUARY 2015 TO DECEMBER 2016, AND THAT THE FILES SHOULD INCLUDE ALL DEATHS AND ALL COLLAPSES, NOT JUST ONES THAT WERE ‘UNEXPLAINED’ OR ‘SUSPICIOUS’”.

PE:

Did you need to know how many cases there were to ask for all the notes?

DE:

It’s only after reading the Guardian piece from Conn & Lawrence that I realised that Cheshire Police had liaised with statisticians initially. I knew nothing about that.

As for the number of cases I was dependent on the Police and Chester clinicians identifying the cases. Naturally the conspiracy theorists (and Richard Gill) won’t be satisfied with that, alleging “selectivity” no doubt. As Chester Police are reviewing 4,000 cases, which would mean reviewing every baby in Chester from the time Letby worked there, one can expect a conclusive response.

MY COMMENT: IT SEEMS THAT DR EVANS HAS MADE THREE CONFLICTING STATEMENTS: THAT HE REQUESTED ALL THE CASES, THAT HE REQUESTED A COUPLE, AND THAT THE CASES WERE SELECTED BY THE “POLICE AND CHESTER CLINICIANS”.

PE:

When you say, "As for the number of cases I was dependent on the Police and Chester clinicians identifying the cases", this means that cases were selected by police and CCH clinicians for you to look at. I have three questions. 1. Why did you not tell the police that it was your job to select cases, not theirs? 2. Were you told how the 33 cases you were given to appraise in July 2017 were selected, if not did you ask, and if you didn't ask, why not? 3. The correct procedure (i.e. an unbiased one) would have been for the police to give you details of all admissions to the neonatal unit during the period of elevated mortality, during the 2-3 years beforehand, and for the period after up until your involvement. This clearly would have been a large number (1-2k) but presumably you would have had a process for selecting cases (a manageable number) that required appraisal (all collapses, whether fatal or non-fatal). Did you tell the police that this would be the correct procedure?

DE:

CoCH medics selected the cases. I don't think one can argue with the numbers who had died. Reviewing all the cases admitted during 2015 and 2016 is being done as far as I know. Reviewing all of them initially would have taken longer (>400 admissions).

MY COMMENT: IT SEEMS LIKE AN EXTRAORDINARY ADMISSION THAT “COCH MEDICS SELECTED THE CASES”. THEY WERE LETBY’S ACCUSERS AND ANYWAY SHOULD HAVE THEMSELVES BEEN SUSPECTS. WHY ON EARTH DID CHESHIRE POLICE ALLOW THEM TO SELECT THE CASES FOR DR EVANS TO LOOK AT?

PE:

Did you ask the police how they had selected Baby O’s case to give you to help you get an idea of the sort of thing they were looking at?

DE:

No. I did not choose Infant O’s case notes, but it seemed a reasonable choice from the police point of view. The poor infant had died. The records were available. Autopsy findings were available.

PE:

There were six babies that died where records and autopsy findings were available. Did you ask why the police selected Baby O in particular?

DE:

I didn’t ask the Police why they chose Baby O. Why do you seem obsessed with this? Does it matter? If so, how? You might as well say that the very presence of the Police introduces bias. How one overcomes that, I’ve no idea. Maybe call in statisticians instead of the police first? I suppose that’s how conspiracy theorists think.

PE:

You make a good point about calling statisticians before the police. I believe NHS Trusts do have their own statisticians so I would be interested to know what role they played if any prior to the police becoming involved (there is no mention of one). As for what happened after the police began its investigation, they did contact statistician Jane Hutton in April 2018 but that did not go anywhere. In fact according to the recent Guardian article, in 2021 the police wrote, “The prosecutor does not agree with our line of inquiry [Jane Hutton and statistics] and has instructed us not to pursue this avenue, any further, at present” (I understand that the CPS can tell the police there is not sufficient evidence to bring charges, but to tell them not to pursue a line of enquiry is interesting. Have you heard of this before?) In fact, according to the article, “Neither the initial engagement with Hutton nor the CPS instruction to the police to drop their line of inquiry into the “validity of the statistical evidence in the case” were disclosed to Letby’s defence team, the Guardian understands”. Do you have thoughts on this?

As well as a statistician, do you have an opinion as to why the police did not engage an epidemiologist who would have considered the broad hospital environment before engaging a paediatrician to appraise the babies’ clinical notes?

DE:

Most NHS trusts do not have statisticians, just the big academic centres. Their information would overlap with that of epidemiologists. Where the statisticians get into a stew is this. They state, correctly, that an increase in annual neonatal mortality from 4, 3, 3 , to 10, 5 is within statistical probability. But it’s not the numbers!! It’s the cause of the deaths – unexplained, unexpected, suspicious, etc. This is why engaging statisticians would not have helped. Presumably Defence felt the same. Was Jane Hutton involved in April 2018. I thought it was 2017 – but welcome clarification. The Guardian article is wrong in stating that the Police did not forward this correspondence to the Defence – so I’m told.

MY COMMENT: IT WOULD BE INTERESTING TO KNOW WHO TOLD DR EVANS THAT CHESHIRE POLICE DID NOT FORWARD TO THE DEFENCE ITS CORRESPONDENCE WITH PROF JANE HUTTON.

PE:

I understand that you categorised the 82 deaths and non-fatal collapses that you were given to appraise either as suspicious or non-suspicious. Were there any of these that you initially asserted were suspicious that did not end up on the indictment?

DE:

Yes. But these were 'later' cases, which I assume the police are investigating.

PE:

You were given 33 cases to appraise in July 2017, 17 deaths and 16 non-fatal collapses. It appears that the 17 deaths were all the deaths that occurred within a particular time frame, whether June 2015 to June 2016 or otherwise. Did you ask why this time frame was selected and if so did you tell them that the time frame should be expanded (to, say, five years from Aug 2012 to Jul 2017 inclusive) in order to avoid bias?

DE:

The time frame [January 2015 – December 2016] was suggested by me I think. I was aware there was a ‘peak’ of deaths during 2015 and 2016 but had no details regarding the actual dates.

PE:

Were the dates not in the clinical notes?

DE:

This is what non-clinicians don’t seem to understand. It was not a matter of Cheshire Police giving me a list of concerning issues an asking me to explain them. Prior to receiving the clinical notes I was not aware of any specific event(s). I was the one who identified each deterioration and separated them into events that could be explained and events that were unexplained / concerning / suspicious / indicative of inflicted harm.

PE:

Noted. On a related matter, may I ask how many of the 17 deaths and 16 non-fatal collapses you determined by December 2017 were suspicious? Also, I know that 8 deaths ended up on the initial indictment (7 on the final one), but how many of the 16 ended up on the final indictment?

DE:

I think I’ve covered this in the letter I sent you yesterday. But I’ve received some more information recently, which adds to my suspicion re some of the 9 deaths (7 murders plus Infant K) that did not form part of Letby’s trial. She was present for all but 2 of the 17 deaths. And when I say “present” I mean in sole charge of the particular baby. I hope you can help with the statistical relevance of that. This is rather scary!

PE:

You write, "She was present for all but 2 of the 17 deaths. And when I say “present” I mean in sole charge of the particular baby." According to Thirlwall Inquiry evidence documents, Lucy Letby was not the allocated nurse for three of the seven alleged murder victims (C, D, I). Do you know why this contradicts your assertion?

DE:

She was not the 'designated nurse'. But she was there. You need to read the Thirlwall Inquiry re Infant C, where she made the nurse looking after C "a bit mad" as she kept popping in despite being responsible for a baby in another nursery. And the parents had to tell her to leave to allow them to grieve in peace. Scary!

DE:

Given the involvement of the Police one could not avoid thinking that there was more to this than simply a ‘bad run’. As I was unaware of the dates of the deaths, having as wide a window as possible seemed reasonable, so by covering the whole of 2015 and 2016 one was unlikely to overlook a specific event. Case 34 [2nd insulin poisoning] was only discovered in 2019. The wider the ‘window’ the better of course. But I felt that 2 years was reasonable, extending well beyond the time of the ‘peak deaths’ There were no deaths in the unit in 2016 once Letby was removed from clinical duties apparently. [The unit had been ‘downgraded’ to Level 1 at some stage in 2016 but I’m not sure when this occurred.]

PE:

According to hospital data acquired via an FOI request there was a death in August 2016. This may have been a baby that died after being transferred away from CCH but should this not have been considered in the same way that the death of Baby K (who died after transfer and was on the original indictment as an alleged murder victim) was considered?

DE:

I’d welcome information regarding the death in August 2016.

PE:

I do not have any information about it other than that it was in the table of mortality data (as a late neonatal death) provided by The Countess via an FOI in 2018 (see https://www.whatdotheyknow.com/request/neonatal_deaths_and_fois - incoming-1255362). Are you in a position to ask for information about this death? You’ll also see from the table that there were a total of 6 neonatal deaths in 2017 and 2018 which contradicts what Dr Brearey said on Panorama last year about there having been no deaths since Letby was taken off the unit/the unit was downgraded in June/July 2016.

DE:

I’ve no information re the deaths in 2017 and 2018. It’s not the numbers [of deaths] that’s significant; it’s the cause that’s important.

PE:

If you'd welcome information about the August 2016 death, can you ask the police or hospital for it?

DE:

No. No longer involved. How would it help? I've given you information that is relevant to you as a statistician. So why do you have difficulties responding with a ststistical analysis. Chi squared, probability, may be a correction if the numbers are small - hardly rocket science. Just statistics. And y D Phil friend will help if required. Straightforward according to him. So let's stick to what we are trained to do. You are welcome to pass on any clinical query to one of your anonymous neonatology contaccts.

PE:

Given that you have said you ended up appraising 82 cases (let’s say for the sake of argument that this was 17 deaths and 65 NFCs, though you of course can correct me if it’s material), did you know the basis on which the first 16 NFCs were selected? This was only a quarter of the 65 NFCs you ended up appraising. Did you ask if the 16 you were initially given were all the NFCs that the police at that time were looking at i.e. they did not at that time have the other 49 in their sights? 16 was clearly a small proportion of the total NFCs that occurred during the period in question (I have been told by medical experts that there are many more NFCs than deaths, which of course is logical). Did you ask how the 16 NFCs were selected, in order to ensure that your review process would avoid bias?

DE:

Of the 17 deaths, I identified 7 cases whose death could not be explained on the basis of a natural event and included a pattern of collapse that I found concerning.

PE:

You have said publicly since the trial that some of these other ten deaths were suspicious. Why did you not say that during the investigation?

DE:

I notified Cheshire Police about my additional concerns in September 2023. They all had underlying clinical problems, so identifying an inflicted injury in an infant with serious natural (congenital) abnormalities is virtually impossible. It turned out that Letby was present when most of them died.

PE:

Are you able to tell me how many of them Letby was present for?

DE:

As of this week I’ve decided to review all 82 cases other than the ones in the trial, therefore (82 – 17) 65. It’s taking some time but so far she seems to be present at all of the ones I’ve reviewed to date. Note that these cases are “selective”, so the conspiracy theorists will simply say that the cases were chosen because the clinicians “knew” Letby was on duty. And with idiots like Richard Gill around, and the Guardian newspaper giving an unfettered platform to a barrister acting on behalf of England’s worse serial female killer, the publicity will endure.

PE:

Were you asked to do this by Cheshire Police?

DE:

PE:

You were given 33 cases to review in July 2017, then another 28 later (total 61). Then you I think told Phil Hammond you reviewed a total of 82. Why do you need to review 65 (82-17) again?

DE:

What has this to do with statisticians?

PE:

You write, "It’s taking some time but so far she seems to be present at all of the ones I’ve reviewed to date." Why are you reviewing them in terms of whether Letby was present rather than whether, per your other messages, incidents in your view were or were not suspicious?

DE:

What has this to do with the figures I've given you re Letby's presence. You (and that abusive guy Gill) have been bitching for months that the spreadsheet did not contain information regarding the other deaths. I''ve given you the information regarding her presence and the other deaths, and you don't seem to be able to respond. As a clinician, and an experienced witness I tell people what they need to hear, as long as it's within my expertise of course. I don't tell people what they want to hear. So, let's get a response from you regarding the figures I've given you. As far as any clinical query, you caan ask your clinician friends to get in touch. Not heard from any so far. And I'm not holding my breath.

PE:

DE:

I had expected that a more thorough review from the local paediatricians would have discovered an explanation that I had overlooked for one or more of the seven.

PE:

There may not have been more thorough reviews from the local paediatricians but six postmortem reviews had found natural causes. Then there was the review of Jane Hawdon and the forensic reviews of pathologist Jo McPartland that came to very different conclusions to yours. Why did they all miss what you saw?

DE:

I’ve read some of Jane Hawdon’s reports. They are not very comprehensible. I’m not commenting on differences of pathology opinions. That’s for the pathologists.

PE:

DE:

These 7 babies, identified by me in 2017, were the ones Letby was convicted of murdering.

PE:

Did you request full genome sequencing on Guthrie cards to test for genetic factors? If not, why not?

DE:

I did not request genome sequencing. Why was that necessary? Are you aware of any genetic disorder / inborn error of metabolism that presents the same way as any of the 7 murdered babies? [Two of the dead babies have a surviving twin, who have not shown any unusual disorders. The triplets were ‘identical’. The survivor is fine].

MY COMMENT: IN MARCH 2018, DR EVANS TOLD CHESHIRE POLICE, “CONSIDER DOING GENE SEQUENCING FOR [BABIES O, P AND THEIR SURVIVING SIBLING] AS PER DR KOKAI SUGGESTION”.

PE:

You’re right, I’m not a medic so I don’t know of any genetic disorder / inborn error of metabolism that presents the same way. It’s just something I have read about that could have been done. Given the questions that are now being raised by other medics about alternative causes of death and collapse, perhaps conducting those tests might have helped you?

DE:

It's cherry picking really. Fuels the conspiracy theorists and the “Poundland Poirots”, as noted by journalist Christopher Snowdon.

PE:

I do not understand why you say that requesting full genome sequencing on all babies whose cases you were appraising should be considered cherry picking. Can you explain?

DE:

No.

PE:

Despite medics before you (postmortems, Hawdon, Rennie, forensic reviews) finding non-criminal explanations for all the deaths and non-fatal collapses, you disagreed with them all and said they were unexplained. If you felt they were unexplained, why would you not want to request full genome sequencing so as to be able to discount genetic factors?

DE:

Epidemic of genetic disorders in a small city in England eh? Limited to 13 months. Disappear when a member of staff is removed from clinical duties. Oh, and the triplets were identical. The surviving one is fine. Waw!

PE:

DE:

Of the other 10 deaths, one was Infant K, whom Letby was found guilty of attempting to murder at the retrial. I had not identified anything concerning her management during my 2017 review as the consultant involved with her initial resuscitation had not recorded anything specific in the baby’s records at the time! Infant K was transferred to Arrowe Park Hospital but died 2 days later. She was very premature and never stabilised.

PE:

Do you find it concerning that the consultant did not record anything specific at the time but did so later?

DE:

I agree. The consultant should have recorded his concerns.

PE:

DE:

Of the other 9, two died elsewhere. One was severely asphyxiated, transferred to a tertiary unit, but died fairly quickly. 4 infants were premature (2 x 29 weeks and 2 x 30 weeks). Two were infected prior to birth, and 2 subsequently. Infection prior to birth is more challenging to treat, as sepsis is already established. Premature babies are prone to infection, and while most infants at Chester survived infection – the doctors were very quick to prescribe antibiotics, it would have been impossible to separate the natural cause of death from a death that was ‘assisted’ by poor clinical care or deliberate harm. [One of the babies was transferred and died later in a tertiary unit.] The other 4 infants all suffered complicated congenital problems. As with the premature babies who died of infection it would be impossible to separate a ‘natural’ cause of death from a death that was ‘assisted’ by poor clinical care or deliberate harm.

PE:

Why did you not suspect that this baby had been asphyxiated intentionally?

DE:

The asphyxiated baby was asphyxiated before she was born. Sadly she was virtually stillborn. Apgar scores were 0 at 1 and 5 minutes. Her asphyxia occurred prior to her birth. This was confirmed by the presence of amniotic squamous cells in her lungs on autopsy.

PE:

DE:

The other 4 infants all suffered complicated congenital problems. As with the premature babies who died of infection it would be impossible to separate a ‘natural’ cause of death from a death that was ‘assisted’ by poor clinical care or deliberate harm. Of the 17 NFCs [16 + 2nd insulin poisoning] I received, the survivors from the original 34, I can but assume that the Police received these cases after due scrutiny from the local paediatricians. You are of course correct in saying that one would normally discover more NFCs than fatal ones. But in this scenario at least seven fatalities [the ones murdered] should not have been there. Prior to Letby’s carnage there were very few deaths annually at the unit. Survival rates were comparable to ONS figures for England & Wales for 2015 & 2016, even for the smallest babies.

PE:

There was a third case of hypoglycaemia. Why did you not consider that suspicious?

DE:

The 3rd insulin poisoning. I did consider it suspicious and said so. As you know CPS do not discuss prosecution process with witnesses. I don’t know why it was not included.

PE:

You may not have known at the time but having now seen Letby's rota, for how many of these was she "present" for?

PE:

I did not see a response from you to this. Perhaps given the difficulty of reading the questions in the PDF you missed this?

DE:

I refer to yesterday’s letter to you. She was present for 15 of the 17 deaths.

PE:

That [carnage] is quite an emotive word!

DE:

Carnage. Found guilty of the murder of 7 babies and the attempted murder of 7 more in 12 months in a neonatal unit. Yes, carnage.

PE:

I suppose I was a bit surprised at your use of this word given your role as an objective medical expert, that’s all.

PE:

DE:

Of the 48 later cases (82 less 34) I received all these [plus the second insulin case] following Letby’s initial arrest in July 2018. [She was eventually charged in November 2020]. I wrote to Cheshire Police in September 2023 (after the guilty verdict) suggesting that up to 25 cases should be examined more thoroughly. These include some cases from the original 34 whose episodes were not included in the trial as well as a number from the later 48. These were reports I had prepared during 2019 – 2021. They acknowledged my letter and I assume that the files are / have been reviewed by other independent clinicians. I have had no contact with Cheshire Police since September 2013 The 48 came from numerous sources. Several were cases initially prepared by Dr Sandie Bohin and ‘peer reviewed’ by me. [Sandie, and Dr Martin Ward Platt had peer reviewed my initial 34 cases]. Other cases came from different sources, including from parents expressing concerns about their baby’s care. They are a random group really and do not fit into any ‘pattern’. After reporting restrictions were lifted I received case files for 2 cases via journalists! I have forwarded my response to the Police. [One is very concerning, the other not]. The Police are on the record as investigating 4,000 cases! There were 60 people working exclusively on Operation Hummingbird when I left Manchester in April 2023. Presumably they are reviewing Liverpool as well as Chester cases. I’m told that Letby worked in Liverpool in 2012 and 2015. [Chester NNU admitted around 400 babies annually, so looking at all cases from 2102 to 2016 (when Letby was working there) would mean around 2,000 case files].

PE:

Why did you not say this during the investigation?

DE:

I had prepared these reports during 2019 – 2021, later than the original 34. For purely logistical reasons Cheshire Police have separated the investigation into phases. I suspect that many of these cases will form / are forming their ongoing investigation and may appear in future charges. I’m not involved with the investigation and am not privy to any updated information.

PE:

Are you able to tell me how many of the 48 later cases you appraised ended up on the indictment?

DE:

None so far, as their cases were reviewed after Letby’s initial arrest in July 2018.

PE:

If none of the 48 ended up on the indictment, and you appraised 34 cases (17 deaths and 17 non-fatal collapses), this means that all 17 non-fatal collapses you were given to appraise in July 2017 ended up on the indictment (there were 24 incidents on the roster table - 7 deaths and 17 NFCs) and thus were all ones where Letby was on duty. Why do you not consider picking ONLY NFCs where Letby was present to be cherry picking, given that there would have NFCs during the period that she was NOT present for?

DE:

No! The "48" were later cases. The Police are presumably reviewing them as part of their ongoing investigation.

PE:

DE:

At the Thirlwall inquiry one of the barristers disclosed that breathing tubes of babies were displaced during 40% of Letby’s shifts at Liverpool in 2012 and 2015 and on <1% of shifts when she was not on duty. Those figures need careful scrutiny in my opinion as the figure of <1% seems very low. It may be that it relates to displaced breathing tubes where the displacement is ‘unexplained’. If that is the case the 40% figure is very concerning. I hope that this information is of some help to you. I am neither a sceptic or a cynic when viewing statistical information, and I think I have a reasonable understanding of the use of statistics as applied to clinical research. As I have been quoted several times the prosecution did not seek a statistical opinion. Presumably they would have done so if they felt statistics were a significant part of the trial. Her Defence did not seek a statistical opinion. Presumably they would have done so if they felt that stats were being misconstrued in some way,

I have found the outpouring of intemperate language and astonishing vitriol following the lifting of reporting restrictions wholly unedifying. It’s worse than Trumpian, worse than the most passionate adversaries of political conflict. I avoid X, but ‘helpful’ journalists have forwarded astonishing bilge and abuse from a statistician in Holland called Richard Gill. I cannot recall ever reading such loathsome remarks. Presumably he is a Fellow of the RSS. I believe that if he represents the opinion of the esteemed Fellows, it reflects poorly on the whole organisation. I can only hope that a reasonable discourse between 2 professional people allows more light to enter the discussion and dissipates the heat, much of which generated by people who should know better.

PE:

The roster table would have been very convincing for jurors. It was described by the prosecution as a 'heat map' which is a statistical construct. Is it not possible that counsels, particularly the defence, did not appreciate that the roster table was about statistics, and therefore that it required appraisal by a statistician? They are lawyers after all, not statisticians.

DE:

It is up to the Defence to get their experts. Presumably they did not consider that statistics were relevant. You could ask them, but they won’t talk to anybody apparently. As of 5 pm tonight I discovered (Guardian) that the Police had spoken to a statistician, Jane Hutton in May 2017, 2 months before I became involved. I knew nothing about that until today.

DE:

I’ll forward you a copy of the rota and my calculation re shifts next week. It would be interesting to look at the number of deaths when Letby was on duty compared when she was not. I suspect the figure will be ‘statistically significant’ [p<0.05 and all that] but whether it is ‘clinically significant’ is another matter. That’s why I steered away from statistical analysis from the very beginning. I’ll be in touch next week.

DE:

Dear Peter. Thank you for placing all the correspondence in one document. I shall respond to the queries asap. Meanwhile I’ve looked at some information that may be useful. Much has been made of the fact that the spreadsheet identifying Letby’s presence was limited to those deaths that formed the prosecution case, and that the chart should include all the deaths. The prosecution argued that the spreadsheet was presented to show that Letby was present at the time – at the scene of the crime if you like. Nevertheless I thought I should look at all the deaths and note the following. The deaths occurred between 31 March 2015 and 24 June 2016. (As noted earlier I’ve no record of any deaths during August 2016). I received copies of 17 deaths recorded between January 2015 and December 2016. Three of the infants were transferred and died elsewhere. I note the following:

7 deaths that formed the prosecution case: Letby present for all 7

3 deaths elsewhere: Letby present when 2 of the 3 deteriorated. One was Infant K – she was the one at Letby’s retrial. One was a very preterm infant. [The other was very asphyxiated at birth and died elsewhere several hours after transfer]

4 deaths associated with congenital abnormalities: Letby present in 3 cases. One had cardiac problems [Ebstein’a anomaly]. She was however stable but suddenly collapsed and died when in Letby’s sole care. One had multiple congenital abnormalities deemed to be incompatible with life. One had multiple congenital abnormalities but was deemed stable before suddenly deteriorating when in Letby’s sole care. Resuscitation was performed by a consultant paediatrician but was unsuccessful. [The other infant died within 2 hours of birth from conditions deemed to be incompatible with life.]

3 deaths associated with prematurity and infection. Letby was present in all 3 cases.

In summary: Letby was present when 15 of the 17 babies died. She was present at the point of deterioration for all 15 cases.

I have also looked at some other items that you may find interesting. I have received a copy of Letby’s work rota from 1 June 2015 to 30 June 2016, as calculated by Cheshire Police. Nurses tend to work ‘long shifts’ consisting of 12.5 hr shifts during the day or during the night. There are therefore 14 shifts per week. During the above period of 57 weeks there were (57 x 14) 798 shifts. Letby was on duty for 163 shifts, which is 20.4% of all shifts. 20% attendance is about average for a nurse working full time. There were 15 deaths during Letby’s 163 shifts. There were 2 deaths during the (798 – 163) 635 shifts when she was not on duty.

I’m not sure whether these figures are of any statistical significance, and if they are whether they are of any clinical significance. I would welcome your views.

DE:

Thought I should enclose some more information for you, having never considered that “Mortality per nurse shift” was ever a relevant statistical or clinical concept before reading of the 40% v <1% difference in breathing tube displacements at Liverpool when Letby was on duty.

Allowing for 12.5 hr shifts one would have 730 shifts per annum.

Mortality rates at Chester for 2012, 2013 and 20014 were 4, 3, and 3. I calculate this as 0.5, 0.4 and 0.4% mortality per nursing shift. This compares with the figure of 0.3% when Letby was NOT on duty during the 13 months I've noted in my letter to you. The mortality rate of 9.2% when she was on duty is therefore a massive outlier.

What this means if anything is, I believe, a matter that is of statistical usefulness and outside my expertise. Its usefulness as something that is of clinical significance is a matter that needs exploring.

DE:

Thanks for keeping me updated. No rush.

This the first time in the Letby case I’ve explored the possibility of using statistics. As I’ve noted the 9.2% figure for deaths per (Letby) shift seems a massive outlier compared to figures of <0.5% otherwise. At least the figures I’ve given you cover all mortalities over the specific period, and, indirectly, the years 2012 -14. (Indirectly as I don’t know whether Letby was on duty during one or more of those deaths.).

Whether it’s CLINICALLY significant or not demands a combined statistical/ clinical view.

Let’s get the statistics first and explore the clinical issue subsequently.

DE:

9.2% v 0.3%. The significance of these 2 variables (using actual figures not % of course) is what I need.

DE:

If you can't deliver on this analysis I'll need to involve my D Phil friend instead.

PE:

Again, apologies for the tardy response.

I have greatly valued and appreciated our correspondence thus far but felt I was starting to lose track of everything! So, I have created the attached spreadsheet which I hope will enable both of us to follow things and thus to continue to correspond. It has two worksheets, “Emails” and “Threads”. I suggest you ignore “Emails” and go straight to “Threads” where each column is a chronological (oldest message at top) thread (you are light pink, I am light green!) You’ll realise that if you scroll down you will see populated light green cells at the bottom of columns which are my new questions to you. I have added some blank light pink boxes for you to fill in where you are willing.

You’ll also appreciate that a thread that starts off as one question/comment sometimes splits into multiple questions/answers.

With respect to your proposed statistical analysis, please allow me a little more time to consider a response.

DE:

Thank you for your latest. I shall forward a response to you tomorrow (Wednesday).

I’m disappointed that you have still not addressed the statistics issue and wonder if I can help.

I discussed the figures with a good friend of mine when we met up over the weekend. He is a City financier with a D. Phil in statistics from Oxford. I showed him both the percentage figures (9.2% v 0.3%) as well as the actual figures of Mortality Rates when Letby was on duty compared to when she was not on duty. He found the figures quite astonishing, and rather troubling.

I’m meeting with another group of journalists later this week. I think they will be interested in your responses.

I had assumed that your delayed response was caused by your concerns regarding your elderly father. But I’ve since heard that you have had time to correspond with your fellow statistician Richard Gill (87 abusive tweets about me so far apparently - I don’t have an X account) as well as checking out my GMC position, so it’s not as if you are overwhelmed with work.

I look forward to your interpretation of the statistics I’ve sent you. I’ll address your clinical queries as I don’t think you have fully grasped the complexities. (Please don’t take that as a criticism. I’m afraid clinical practice is not as binary as interpreting numerical analysis).

I’d welcome your reply to my statistical analysis by Thursday morning if possible- prior to my meeting with my journalists later that day. If this is not possible I’ll ask if my D Phil friend could join us briefly to confirm what appears to my ‘non-statistical’ eye to be some very important and significant statistical findings.

One final point. I’ve only just discovered that you were one of the 2 lead signatories (with Dr Dimitrova) of the letter you forwarded to the RtHon Wes Streeting demanding the postponement of the Thirlwall Inquiry. I’m not sure if you are in touch with Dr Dimitrova or any other neonatology consultants. If you are, you are welcome to give them my email details, and they are welcome to contact me.

DE:

I’ve addressed all your queries but am unable to forward Infant C’s report to you or anyone else, at the request of the parents, via the police.

I don’t think we can take our correspondence any further without getting a response from you re my figures - which I find very interesting.

My journalist friend is desperate to get the facts re the 9.2% v 0.3% mortality rate per nursing shift, which I am happy to share, but believe that having a statistics expert to address their significance would be useful. My D Phil friend had no difficulty in analysing them.

Can I forward them your email details? I think they may want to talk to you.

PE:

Dear Dewi,

Thank you for your patience in awaiting my response. I can confirm that I have now looked through the data you sent me and your proposed statistical analysis. Whilst I can see from the way you have presented this data that it may seem like these numbers are significant, in order to carry out a robust and accurate statistical analysis, we would need to take into account a variety of other factors, such as:

1. How many nurses are there per shift?

2. Are all shifts the same duration and is there a difference between the number of nurses on day vs night shifts?

3. How many nurses are part time vs full time, and how many extra shifts did they do on average during that time period?

4. What are the differences in competencies between nurses?

5. We need to compare day with night shift data due to the known higher incidence of adverse events happening at night; as well as the proportion of shifts in terms of days vs nights that Lucy worked, as well as the other nurses.

6. We need to have a look at all the names of people on shifts when the deaths occurred. And not just the deaths/collapses that ended up going to the criminal court, but all deaths/collapses. For all nurses, as well as doctors.

If you can forward me the missing information above, I would be happy to input into the analysis of this data. If this information is not available to you, I’m afraid it will not be possible to analyse this data in a statistically valid way. I also suspect that for this type of analysis, Fisher’s exact test would be more appropriate than a chi-squared framework. With regards to the second set of data regarding extubations, I would also be very happy to help you with this analysis. The numbers put out appear to be very concerning.

You are correct that I was the lead signatory together with Dr Dimitrova regarding the raising of concerns about the terms of reference of The Thirwall Inquiry. This of course is not related to your role as medical expert. I do obviously have Dr Dimitrova’s contact details - she initially got in touch with me. I don’t think she has any presence on X either so she may not be aware that you have said you are happy to be contacted by neonatologists. Would you like me to forward her any communications from you and ask her to get in touch? I can certainly assure her that you have been most polite and engaging with me so am sure she would have the same positive interaction with you as I have.

Thank you also for addressing my most recent questions. Please allow me a little time to digest. Please also feel free to pass my details to your D Phil friend.

PE:

I saw on Reddit your list of air embolism papers that you cited. May I ask why it did not include the below paper (one of the papers cited in the Lee and Tanswell paper that was the focus at trial)?

Paper: Quisling et al (1974)

Best wishes,

Peter

PE:

Three things:

1. I wonder if you managed to look at Quisling et al (1974)? It looks relevant to the Letby case so wondering why it was not on your reference list of 18 papers about air embolism?

2. I know you concur that statistical analyses are pertinent in relation to the Letby case and indeed put your own statistical analysis together regarding shift data. I certainly would still like to help you with that and provided you a little while ago with a list of the information that would be needed. Did you have any luck getting that? On a related matter, I have now had a lot of contact with many statisticians who all feel that the statistics presented at trial (the elevated mortality, the roster chart) were such that it was clear that Letby’s trail was unfair. I’m sure you will have your reasons as to why they are wrong but I was wondering if you have had contact with any statisticians who believe/are sure Letby’s conviction is safe? I have not come across any but perhaps you have. If so, would you be able to put me in touch with them?

3. I have been made aware that, according to ChatGPT (response to question "Which month of 2017 was the Independent Medical Review commissioned?”):

"The Independent Medical Review in the Lucy Letby case was commissioned by the Countess of Chester Hospital in February 2017. This was after internal investigations by the hospital failed to identify a medical or environmental cause for the rise in neonatal deaths and collapses. The hospital sought external expertise to thoroughly examine the incidents and provide an objective assessment. Dr. Dewi Evans and other medical experts were brought on board to review the cases, which eventually led to the identification of suspicious patterns and the referral of the findings to Cheshire Police in May 2017."

My question to you is, simply, were you a member of the Independent Medical Review team commissioned by CCH in February 2017?

PE:

You mentioned in your email of 19 Nov that you would respond the next day to my queries that I set out in my 15 Nov email (below). Just to let you know that I did not receive anything, in case you sent something and for some reason I did not receive it.

Also, in relation to Q3 in my email below, you may be interested in this Freedom of Information request that I have submitted: https://www.whatdotheyknow.com/request/independent_medical_review_in_th. Obviously I did not explicitly ask whether you were involved in the review in question, but you’ll see I have asked for details of it. You’ll see I have added further information to the FOI this morning, citing reference to the Feb 2017 review initiated by Dr Stephen Brearey. Even if you were not involved in this, do you know anything about it?

DE:

Sorry for the delay getting back to you. I think that this response is probably my last bit of correspondence. There’s an awful lot of disclosures emerging from the Thirlwall Inquiry and it would be difficult to express a view without noting one or more of those items. Out of courtesy to Lady Thirlwall I believe it’s only right that one waits for all of her evidence to be presented and for her report to be published.

As for your earlier questions.

I did not include the Quisling paper presumably because my search engine(s) did not get back to 1974. As the information is disclosed in other publications it does not add to the scientific knowledge mentioned at the trial.

My comment: The Quisling (1974) paper was called "Postmortem gas accumulation in premature infants". There is a link here - https://pubmed.ncbi.nlm.nih.gov/4608592/. It appeared in my search engine so not sure why it did not appear in Dr Evans'. And the references he cited in his witness statement did not include papers about postmortem gas accumulation in premature infants, contrary to what he wrote above.

As for the Medical Review of February 2017 I was not involved and don’t think I knew about it prior to your message.

I’m very disappointed in your failing to address the information re Letby’s presence during the deaths. The general whinge of the statisticians re the spreadsheet was that the prosecution had not disclosed information about all the deaths. You now have that information, and I’ve asked you a perfectly reasonable question.

What is the statistical significance if any of her presence when 15 of the 17 babies collapsed and died. (The other 2 babies sadly had unsurvivable conditions).

I also gave you information re her shifts (which I only received in September this year). I’m very aware of other variables and I don’t have the information. But that should not stop you given a qualified opinion.

My final concern relates to a posting of yours on social media. You make gratuitous and insulting comments regarding my reason for my involvement in this case. What happened to manners?

You also note the following.

“In the Letby case not only was a retired paediatrician allowed to override a number of medics, including a forensic pathologist, who all said there was no evidence of crime, but when he declared in Dec 2017 after being part of the investigation for 5 months that crimes had been committed he knew he would be engaged by CPS as its main medical expert, and onto a nice earner.”

I think this is the most ill informed paragraph I have ever read, at least from an alleged intelligent professional, in relation to how due process works in the Criminal Justice System (and the Family and Civil Courts for that matter).

No one’s opinion “overrides” anyone else’s! If there is a difference of opinion both are entitled to present their evidence on oath, and following cross examination. The decision regarding which opinion is deemed more valid is a matter for the Jury, after considered advice from the Judge, and following the summing up from advocates for the Prosecution and Defence.

As for “overriding” the opinion of a forensic pathologist, you have to be joking! I don’t even express an opinion on pathology matters other than quote them in reports.

Your comment regarding my being engaged by CPS is also incorrect, confirming a rather disturbing level of ignorance. I have prepared reports for the prosecution on numerous occasions where I was not called to give evidence despite my reports being very supportive of the prosecution. Look up the murder cases of Finlay Biden, Alfie Steele and Jacob Crouch. I prepared reports for all of them. All the defendants were found guilty (in 2023). But because I was not called my nice earner from the CPS was a sad £0.00. [Police Authorities pay for one’s reports].

I fully expected you to respond to my 9.2% v 0.3% query, and would understand if your response was qualified. But ducking it all together? No use at all! And of course this aspect of the case is the only part for which you can claim any expertise.

I’m afraid you have shown yourself to be out of your depth in relation to many aspects of this case, and I had no idea you were so ill informed regarding due legal process. Asking if I was involved in a meeting that took place in February 2017 (I’ve not seen any minutes of any such meeting) is what I would expect from a conspiracy theorist, someone who cannot face up to what we clinicians call evidence.

So sit back and digest the disclosures from the Thirlwall Inquiry. Consider also if you can the feelings of the families whose babies were murdered by Letby and the families of babies harmed by Letby. That’s was not a matter decided by me. It was decided by a Court of Law and confirmed by 3 Judges from the Appeal Court. And according to evidence from Dr Stephen Brearey from last week’s Inquiry Letby is likely to have murdered more babies. I’m no longer involved with the investigation, so it’s a matter of waiting for developments.

I don’t believe that there is anything to be gained by our continuing our dialogue. It’s been interesting. I wish you well.

PE:

I’m sorry I was not able to provide a qualified opinion on your statistical analysis regarding shift data. In order to provide one further data was required per my email. There appears to be information emerging about deaths in 2015/6 other than the 17 you mentioned which of course would need to be taken account of too.

As for my social media posts, I have not added to them since we started corresponding so they have always been there for all to see. I never attempted to hide them and was open from the outset with you about my statistics and science credentials.

I likewise wish you well. Perhaps we might reengage when the dust has settled.

DE:

Dear Peter. Just a query. Given what Dr Brearey said in evidence today.

Are you, or have you been, a member of the Brotherhood of Freemasons?

(Will respond to your latest queries tomorrow).

Lead consultant Stephen Brearey said he believed Lucy Letby had murdered children prior to June 2015.

Source: BBC News

https://search.app/JM5F6a7EDAbgQGXi9

PE:

What I have found on the BBC in relation to your question is below, but you may be referring to another part of his testimony about freemasons?

The inquiry heard that Dr Brearey had previously suggested that a number of former bosses were freemasons. Richard Baker KC, representing some of the babies’ families asked the consultant: “You had a sense that there might be some deals going on behind the scenes, some element perhaps of corrupt behaviour?” Dr Brearey answered, “Yes, people had that impression and there were certainly rumours of that kind”.

I am not one of the “former bosses” (presumably of the hospital) as I think you know, so not one of the individuals who Brearey suggested were freemasons. That said, I am not nor ever have been a member of the Brotherhood of Freemasons. I am intrigued by your question though. Are you suggesting that I might be colluding in some way with the former hospital bosses?

Many thanks re my latest queries.

DE:

Just a brief comment. At yesterday’s hearing it was confirmed that there were no deaths at Chester in 2016 following Letby’s suspension at the beginning of July. No doubt you will now find another excuse as to why you can’t analyse the information I gave you weeks ago.

Or you can return to posting gratuitous comments about me of course - like the one you have posted previously. A good friend of mine is keeping an eye on your social media activity.

PE:

Please forgive me for the radio silence. I hope you are well.

I see your statistical analysis that the mortality rate when LL was on duty was 9.2% (30 times higher than the average of 0.3%) made it into the Telegraph recently - https://archive.ph/UpXwG. Congrats!

Perhaps you may be interested in my further thoughts on it, as below.

Per my previous email, I believe there are adjustments that need to be made to your calculation and I do not have the data to be able to do that. Adjustments that are required fall into five categories, as below.

a) The 9.2% is based on 17 deaths in 2015 and 2016 which is likely the wrong number (too low). According to Mark McDonald's ‘audit’ referred to in the media there were 23 (possibly 24) deaths in 2015/16. It is not known whether LL can be associated with any of these ‘extra’ deaths.

b) You base your calculation on shift data that was shared with you (in September I think?) which I cannot verify. It is certainly at variance with shift data released via The Thirlwall Inquiry. Also, was the shift data document you received legally privileged and if so, since you were no longer involved in the case, should you have received it? And should you have shared it with me?

c) LL may have been on duty at time of death in relation to the deaths on the indictment but in relation to some of them she was not on duty/on the unit when the attack invoked by the prosecution that led to the death in question occurred. Two examples of cases where LL was not on duty at time of alleged attack:

· Baby C: LL was not on duty when X-ray that was the prosecution’s proof of inflicted harm was taken on 12 June 2015.

· Baby O: I believe from transcripts that you initially said the attack (a physical attack on the liver) took place in the early hours on 23 June 2016 but LL did not come on duty until later for the day shift. I understand later you said the attack happened on the day shift when LL was on duty. Also, I believe you conceded at trial that what you had said was bruising over the liver was not in fact bruising because you learned it had been transient (you then invoked air embolism because the rash had disappeared). So why did you later say on Raj Persaud/Tortoise Media that the reason you knew so quickly that harm had been inflicted was because you saw bruising which you knew when you did the interviews was not bruising? Also, we learned at Mark McDonald’s press conference yesterday that the liver damage was caused by a doctor inserting a needle into the abdomen during resuscitation (excessive ventilation pressures had not only caused problems for Baby C but had also pushed down the liver). Why was this not in your testimony?

These are two examples but there may be similar situations with at least some of the other 5 deaths on the indictment.

d) The below adjustments need to be made in order to compare like with like, an essential requirement for your analysis to be statistically robust:

· More deaths occur at night and LL did more night shifts than other nurses.

· LL was a more senior nurse so would have been assigned to sicker babies than other nurses.

· LL was a full time nurse so should not be compared with nurses who were part time, agency nurses, or full time nurses who did not work for the entire 24 months (they may have joined or left during the period).

· LL was single, saving to buy a property, and enthusiastic, so would have done more overtime.

· Bad luck. Even if after adjustments LL’s rate is higher than the average, the difference may not have been statistically significant given small sample size (number of deaths - even 24 is low for this calculation).

e) If deaths prior to 2015 when LL was working at CCH and LWH are now being investigated then these should be included too. We do not have shift data for deaths when Lucy was working at CCH prior to 2015 or at Liverpool Women’s Hospital.

In relation to d), there is an interesting football analogy. In 2023/4, the Premier League’s top goal scorer was Erling Haarland, with 27 goals which of course does not make him the best player. 27 goals was around 10-13 times the average for all players, depending on whether you include the 300 players in the Premier League list or 500 which is 20 teams multiplied by squad size of 25. While 30 times is more than 10-13 times, the 30 would come down as a result of adjustments a), b), c) and e) above but anyway is in the same order of magnitude (logarithms of 10/13 and 30 are similar). Regardless, of course nobody thinks Haarland scoring 27 goals is suspicious (evidence of some sort of cheating). First off, everyone knows that there has to be a player with the highest number of goals. More importantly, they accept this will be a striker (the equivalent of LL being a more senior nurse), one who makes more appearances (the equivalent of Lucy being compared with part time nurses who worked less), and one who may have been injured less (the equivalent of LL being single, saving to buy a house etc). And even if after adjustments, Haarland is still the best player this could be down to luck and not statistically significant (in LL’s case this would have been bad not good luck, of course).

MY COMMENT: I DID NOT GET A RESPONSE FROM DR EVANS TO THE ABOVE, SENT IN DECEMBER LAST YEAR, BUT I WROTE TO HIM AGAIN IN JULY THIS YEAR, PER BELOW.

PE:

Dear Dewi, I hope this finds you well.I have a general question that you might be able to help me with. It is quite basic so apologies.My understanding is that you say that many of the babies were doing just fine, with oxygen saturation levels nicely in the 98-100% range. How long after air is injected intravenously would a baby collapse and oxygen saturation levels plummet? Some are telling me collapse would be immediate, others that there could be a delay. Which one is it? Or can it be both?Thank you and best wishes,Peter

DE:

It’s a valid question but one that’s difficult to answer as one cannot conduct studies where one injects different volumes of air (or oxygen) at different rates into experimental animals (bar one study with piglets) let alone little babies. A large volume injected quickly will cause immediate collapse- thus the tragedy of the baby who died in Swansea 20 years ago.

It’s even more difficult to offer an accurate time with small babies. A large volume of air injected quickly would cause immediate collapse and death. Where “immediate “ means seconds. If the air is injected into the intravenous line it may take minutes for the air bubbles to get from the plastic tubing into the bloodstream, and the rate of delivery will be very slow (I sent various calculations to the prosecution in the Letby case after measuring over line cannula volumes but was not questioned about it by prosecution of defence). Situation is further complicated in newborn babies when air tracks from the venous side across the PFO to the arterial (left) side of the heart. This is what caused the unusual skin discolouration in many babies as the air tracked through blood vessels close to the skin. Volumes were probably small, which is why some of these babies survived. So the best one can say is that the patient would deteriorate “quickly”, but having to allow for the variations in both volume of air /oxygen given and the speed of the delivery. This was covered very well by Dr Sandie Bohin in one of her testimonies. Clinical medicine never is an exact science! (I’ll forward the research paper re piglets to you when I get back in touch with my laptop if you want. I can’t remember whether I’ve ever sent you my 6,000 word air embolus review: Air embolus 1, 19 06 19_Redacted. You are welcome to that - but wasn’t challenged on it.)

PE:

Thank you. And I would very much like to see your air embolus review, thank you.I note what you say about clinical medicine not being an exact science, but would it have any bearing on speed of collapse whether baby’s Sa O2 is perfect (98-100%) or weaker (91-95%)?

DE:

Not really! The collapses witnessed at Chester were catastrophic, dropping to 50% or less, with commensurate drop in heart rate. Lee’s 2024 update describes the clinical features associated with air embolus in detail. I’ll send that as well. They are more or less identical to the characteristics noted of several babies in Chester. Dewi

PE:

Thank you. I’m not a medic as you know so it’s hard for me when I hear differing views on the same thing, but is there a target Sa O2 for babies and if so what is it? Is it 100%? Or a range e.g. 98-100%?

DE:

The usual target for oxygen saturation is 96 - 100%. Prtemature babies are at risk of retinopathy if oxygen levels are too high, so values in the low 90s can be accepted / tolerated. [One needs to appreciate the graph relating to oxygen saturation and partial pressure of oxygen. This is rather complicated!

My air embolus review to follow.

DE:

What stands out within my searches is the rarity of published work. This is not surprising as air embolus is incredibly rare and departments tend not to write up accidents (accidental air insertion) that could happen in their department. As far as I know inflicted / deliberate harm due to air embolus has not been described previously. (The experiments with piglets , my paragrph 37, is worth noting as it highlights the speed with which air can compromise a piglet).

Although Shoo Lee appears to be getting a lot of publicity his personal experience is limited to 3 of 50 cases he published from Toronto in 1989. Intensive care of babies has moved on a lot since then.

Another interesting point was that Lucy Letby attended a study day in relation to giving intravenous drugs and fluids just a week before the first fatality. Any study day involving instructions on giving intravenous substances would always emphasise extremely strongly the dangers of getting air / oxygen into the bloodstream. Its dangers have been known more or less since doctors have been infusing intravenous fluids into patients. I only heard about her study day sometime during the trial, and I'm not sure if this was mentioned at the trial as evidence. I think (but willing to stand corrected) that at one of her police interview she claimed not to know about the risk of air embolus in babies but knew about the risk in adults. This is a very odd thing to say for a nurse whose professional training and subsequent practice related to babies.

Anyway I'm sure you will have heard of the latest developments, which involve hospital managers and cases from Liverpool, which go back to 2012. I was not involved with the review of cases from Liverpool, so all of this is news to me. I'm more than happy to take a back seat on this one having stopped taking on new cases in 2022 and taking myself off the GMC's licence to practice in June last year. I may manage retirement one day!

Regards

Dewi Evans

PE:

Thank you for your two emails and for sending me your air embolus report. It seems there is a paucity of research and of course as you say a proper empirical study on human babies would be impossible.

I believe there has been some misunderstanding as to whether you opined that NGT air killed the babies or destabilised them. Regardless, how much air do you think Letby injected into babies’ stomachs in the six related cases (Babies C, G, I, O, P and Q I believe)? I cannot recall if you offered an opinion on this so apologies if this is something that I could have found in the transcripts.

You mentioned in your other email that, "The usual target for oxygen saturation is 96 - 100%”. Is this the target for all ages? Prems, term babies, children, adults...

DE:

Dear Peter

It’s impossible to quantify the amount of air, or air plus fluid, required to destabilise a baby! Nearest to a reasonable estimate is baby G. She was fed 45ml. Vomited x3. Yet 45 ml plus 100 ml was still left in her stomach. Therefore the surplus milk / milk and air injected by Lucy Letby was a minimum 145ml, plus the vomiting volume, which is difficult to estimate. Probably at least 50 ml. So an estimated minimum 200ml? (In a 2 kilo baby). An awful lot - 100ml per kilo is equivalent of 8,000 ml in an 80kg adult. That’s around 15 pints. Within minutes!

A probable similar amount in baby Q - which involved clear fluid rather then milk or air alone.

Others were compromised by air in the bloodstream as well so more complicated.

Didn’t do anything by halves our Lucy! I’m fascinated by the folk still in denial. Equivalent of the pre Galileo Vatican I suppose. Or people who think that Donald Trump is fit to be president.

I’ve no idea if the latest disclosures will lead to charges. I’m not involved. I’m trying to reduce my input- not doing more TV interviews but responding to objective questions to named personnel like the above.

Re oxygen saturation, the optimal is influenced by prematurity. Important to avoid too much in premature babies given risk of retinopathy. Ideally one would want to measure partial pressure of oxygen as well as oxygen saturation (normal is around 13). This though requires arterial sample, which may be difficult to get and painful.

Incidentally I hear that your Co signatory Dr Dimitrova demanding that Ladty Thirlwall postpone her inquiry is no longer part of the McDonald campaign and is no longer part of the Ockenden investigation. Have you any idea why? I have told another journalist that she is welcome to get in touch with me, but she hasn’t done so yet. Not holding my breath. Also I’ve no idea whether she has prepared any medicolegal reports.

Dewi

Dr Dewi Evans

PE:

Apologies for not responding sooner.

I’m afraid I do not know the answers to your questions about Dr Dimitrova. If I have any contact with her would you like me to ask if she received the message about contacting you?

What I have seen is today’s Private Eye (attached) piece in which she features. I’m not a doctor but I’d certainly be interested in your thoughts on the article.

With Baby G, how many syringes would 200ml be? Quite a few I imagine.

As for Sa O2, Judge Goss in his summing said that, "Dr Babarao, a consultant neonatologist at Arrowe Park, and to whose evidence I shall come tomorrow, accepted that those numbers did not tally with the oxygen saturation level of 94%, which he said was the optimal saturation level for a preterm baby.” And according to the NICE guidance (attached) the target for premature babies is 91-95%. I think you said at trial a few times that Sa O2 of 98-100% was optimal, or something similar. I guess there is something, as a non medic, that I’m missing here!

Best wishes,

DE:

Dear Peter.

Can’t respond in detail. All discussed at the trial. But I think the 94% figure related to a leak, not oxygen saturation. Happy to stand corrected. If it’s about oxygen saturation 94% is fine.

Afraid I’ve upset the ‘umble ‘ammond, who’s probably spent less time in a neonatal unit than a Chester Plummer.

Dr Phil was still passing himself off as a doctor dealing with chronic fatigue syndrome earlier this year. I discovered he had taken himself off the GMC’s Licence to Practice years ago, so couldn’t have been seeing patients! I pointed this out to him and his biography changed with Tommy Cooper “just like that” speed. I’ll send you the 2 bios if you want.

As for Dr Dimitrova, I’m told she’s no longer part of Mark McDonald’s team - hearsay that by the way. You have been liaising with her so have her contact details and you can clarify her position with Mr McDonald. You could also ask her why she’s no longer part of the Ockenden team. And, as with all my correspondence you are welcome to forward this email to her , and any other medic you know. Not had anyone yet other than your good self has been in touch. Not holding my breath.

So, apologies for not wishing to get involved in a debate involving a C grade comedian with a medical degree. Private Eye is about ‘aving a laff. Nuffink rong wif ‘ ‘at. But they took over 10 years to admit they got it wrong with their support for Wakefield and his MMR and autism hypothesis. Not bought a copy of Private Eye since. (Bar 2 recently). Not worth it.

I’m still trying to retire you know. And the weather in Wales is great for a change. Meanwhile feel free to share my observations if you think it helps

Hwyl

Dewi Evans.

PE:

Dear Dewi,

If it’s not too much trouble to send the two bios, please do! Though it wasn’t so much about what Dr Phil wrote but about his references to what was in Dr Dimitrova’s report about Baby O.

With regard to sats, what I’m hearing from another medical doctor with experience in these matters is that if Sa O2 is persistently over a number of hours being recorded at 98-100% for a baby on CPAP, even if on room air, this may be an indication that plasma oxygen (or whatever the term is) is dangerously high, so PEEP should be reduced. I’m being told that in the case of many of the indictment babies, PEEP was not reduced despite Sa O2 being 98-100%. Should it have been do you think? Apologies if I’m not getting my medical terminology quite right.

Apologies too for keeping you from your retirement, particularly since the weather is nice!

Best wishes,

DE:

He wasn’t on PEEP! He was on Optiflow! CPAP (PEEP) had been long discontinued! Not seen Dr Dimitrova’s report. Can you forward a copy to me.

Tell your contact and /or Dr D to get in touch with me.

(Bios arriving tomorrow.)

Dr Dewi Evans

PE:

I don’t have a copy of Dr Dimitrova’s report I’m afraid. I will get in touch with both my contact and Dr Dimitrova.

What I’ve been told is that for many of the prem babies who were on CPAP (regardless of whether they were ever/subsequently on Optiflow) sats were persistently (over several hours) in the order of 98-100%, compared with the NICE target for prems of 91-95%. What would you have done had you seen persistently high sats in the order of 98-100%?

PE:

Dear Dewi,I hope you are well.Per previous emails, I know you are keen to correspond with Dr Dimitrova. She has given me permission to pass you her email address so I have copied her on this email.Best wishes,Peter

DE:

Dear Peter. I wouldn’t say I was “keen” but my specific reason for liaising with her related to the article from David Rose in Unherd where he published a list of events of cases where Lucy was NOT on duty but concerning matters occurred. I asked David if his contact could get in touch with me, so I would be pleased to discuss the matter with her. No disrespect to journalists, lawyers (or even statisticians) but I believe that these matters are best discussed by clinicians. I’ve got social issues all weekend but I’ll get in touch with Dr Dimitrova from Monday onwards. RegardsDewiDr Dewi Evans

PE:

Sounds good, Dewi. Best wishes, Peter

MY COMMENT: FOLLOWING MY LAST MESSAGE ABOVE, THE NEXT CORRESPONDENCE WAS THE EMAIL FROM DR EVANS LAST TUESDAY.

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