Pathology reports solve “new bowel disease” riddleBMJ 2011; 343 doi: https://doi.org/10.1136/bmj.d6823 (Published 09 November 2011) Cite this as: BMJ 2011;343:d6823
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Best wishes for John Walker-Smith, his family, colleagues and his supporters on the winning of his appeal against the General Medical Council verdict handed down previously involving allegations of professional misconduct.
I personally have believed you to always been a man of the highest integrity and with the best intentions for all the children you have treated over a long and distinguished career.
My thoughts also go out to your colleagues you served with and who were also involved in the gastrointestinal work you undertook. Particularly Professor Simon Murch I would feel it a further injustice if the GMC did not make a further clear statement and rescinded their published findings.
Sometimes justice can be served by a simple apology.
Competing interests: Father of ASD son. Family fully immunised on time and schedule.Have never associated vaccination with my son's condition.
There is a nomenclature and interpretation that can only be expressed by those with a deep understanding of all aspects of clinical and research medicine, terms like 'colitis' expressed by experts may be entirely different to that expressed by a layman.
The general public and the common reader then should give more credence to those experts like Professor John Walker-Smith, Professor Simon Murch, Professor Amar Dhillon and others that have exclusively seen all aspects of the patients that were present at the Royal Free Hospital. Who then made collective decisions based on that knowledge rather than retrospective
Professor John Walker-Smith gives an erudite and detailed explanation of many of the aspects of the bowel pathology at the General Medical Council Procedures from day 75 and on (Thursday 17 July 2008 and on ...)
An example is given...
A description of Child 2's bowel pathology by Professor Walker-Smith Day 77
"Well, this is a very significantly abnormal report. What is of particular interest is that there are inflammatory changes in the ileum. There is mild chronic inflammation with the lamina propria. That virtually occurs in no other situation than Crohn's disease. It is almost specific for Crohn's disease, to have definite inflammation of the ileum, and like, as I have been saying during this hearing, where inflammation in the colon is not so specific, having on the first day mentioned a range of causes. In the large bowel it is highly abnormal to see these lymphoid follicles with active germinal centres within the ascending and transverse colon, and there is a patchy increase in chronic inflammatory cells, but clearly there is the occasional focus of very acute inflammation, cryptitis, inflammation within the crypts, and with mild crypt distortion would suggest that there has been inflammation before, and the large bowel a mild chronic inflammation and very focal cryptitis. So this is a very abnormal result. This is showing both acute and chronic inflammation and with the evidence that there is ileitis, this is very suspicious of Crohn's disease. Simon Murch’s endoscopy report with the aphthoid ulcers and the swollen, and with the halo round the enlarged lymph nodes was, I suggested, early Crohn's disease, and when I saw this report at that time, not at that time, subsequently, I think on 9 September I first did a ward round, it seemed to me that it was at least a possibility that this child had early Crohn's disease."
The reader then should not be surprised by the positive clinical outcomes reported ...
John Walker-Smith Day 77 Correspondence
I was really quite surprised to see the progress [Child 2] had made in his behaviour since he had been commenced on sulphasalazine. His performance in the clinic room was quite transformed. He was no longer destructive, he was quiet and calm and I was able to examine him without any particular difficulty. This change behaviour is difficult to assess objectively.
I have written to the school authorities to get their opinion. From my own perspective (and that of David Casson, who knew him before), there seems to be quite a dramatic improvement in his behaviour. However, I would be most grateful if you could re-assess him yourself and give us the benefit of your opinion.
The clinic sister here tells me that 3 people were required to hold [Child 2] down whilst blood was taken previously, but on this occasion he just said ‘Ouch’ when he had a venopuncture. It is the clinic sister’s independent opinion that there has been quite a dramatic improvement in his behaviour.”
Dr Wozencroft Day 77 correspondence
“On 7th April I saw [Child 2] again with his mother. I observed a striking change in him.
Twice in the course of the interview, he made eye contact with me. As we walked down the corridor towards my office, his mum gave him a specific instruction about how he should walk. He changed his walk accordingly. In the course of the discussion, he made two verbal interventions which, on the face of it, appeared to be relevant to the matter his mother was discuss with me.
I had never seen [Child 2] responding in such an ordinary way. Something has made a significant difference to him since our last interview. Mother believes that it is the medical treatment he has been receiving from the Royal Free Hospital."
Of course the original clinical bowel investigations continued and was reported by letter in the Lancet and described at Day 84 GMC transcripts.
"this mucosal abnormality has been apparent in 47/50 children within the autistic spectrum, whether or not there is any perceived link with immunisation. Thus the lymphoid hyperplasia/ microscopic colitis changes were found in over 90% of the autistic children studied." (Simon Murch, Mike Thomson, John Walker-Smith 1998.)
Further commentary Day 84 GMC transcripts - John Walker-Smith
"What is quite astonishing about this review of children is the high evidence of abnormality. In suspected Crohn's disease, as I say, we had a lower incidence of abnormality. Here we have mucosal abnormality in 47 of 50 children investigated with the autistic spectrum, which almost suggests that this could be a feature of autism per se, although these are children all with bowel problems. So this is a very important observation. The observation I was making, we are going back into a time warp, were just in the early days; here we have a new observation from Simon Murch’s group showing that the germinal centres, which we have commented upon and I have always regarded as so significant, that many of the inexperienced consultant pathologists at the Royal Free did not, that the germinal centres are particularly important in lymphoid hyperplasia. Ki67 is a marker of proliferation. Simon Murch can speak to this himself later on, but his observations are that these are highly abnormal findings in these particular children. Furthermore, it is of importance that by now we have here moved on from the original descriptions of recognising that faecal loading – I am afraid we call it constipation here which does overlap with faecal loading – but here we have emphasised X-ray of the abdomen. Plain radiography is important. We hoped the medical community, by reading this, would perhaps focus more on what was important in this paper – namely the innovative observations – clinicopathologically. "
It is then difficult to balance and reconcile another 50 pathology reports and slides that further evidenced aberrant bowel pathology against the interpretation presented previously by others.
Once again it would be remiss of me not to acknowledge the very clear, caring and professional treatment of disabled children, that continues to be elucidated each time I read the testimony of the doctors involved in this issue controversial as it is.
General Medical Council Fitness to Practice Panel - Tuesday 22 July 2008 Day 77 - Day 84
1. The Lancet, Volume 351, Issue 9106, Page 908, 21 March 1998
Autism, inflammatory bowel disease, and MMR vaccine,Simon Murch, Mike Thomson, John Walker-Smith
Competing interests: Father of ASD Son. Family fully vaccinated. No association placed on son's Autism and vaccines.
This month, we added to our series “Secrets of the MMR Scare” with more on the claim that in the late 1990s Andrew Wakefield and 12 others from the Royal Free, London, discovered a new inflammatory bowel disease. This was one of two sides to the infamous Lancet paper – the other linking the vaccine with autism.
The paper’s Table 1 said that “histological findings” of colitis were made in 11 of 12 children colonoscoped. “Formalin-fixed biopsy samples of ileum and colon were assessed and reported by a pathologist (SED),” it explained. “Five ileocolonic biopsy series from age-matched and site-matched controls whose reports showed histologically normal mucosa were obtained for comparison."
The paper acknowledged Paola Domizio of the London hospital for controls, but she denies the methods described. Not an author, she says she supplied ten, not five, normal biopsies, unspecified for age or site, and a draft of the paper confirms her figure. In any event, the right controls would have been from constipated neurotypical children, not selection-biased, pristine samples.
The Lancet paper went on to say, "All tissues were assessed by three other clinical and experimental pathologists (APD, AA, AJW).”
“SED” was Susan Davies, now at Addenbrooke’s, Cambridge, who was the lead pathology service consultant on the project. At Wakefield’s GMC hearing she said she generally didn’t find “colitis.” She said she raised concerns about use of this word, but was reassured by a “research review”.
“APD” was Amar Dhillon, a Royal Free pathology professor, who now bats the ball back to Davies. Responding to my report, he has confirmed that he used "grading sheets" (which we published) and that he too didn’t report colitis.
“Thus the purpose of my grading sheet observations in 1998 was not, could not have been, nor was it intended to conclude the final diagnostic assignment of colitis (which has to be made in the light of full clinical/endoscopic/radiologic/laboratory data; and response to treatment),” he said.
Wakefield was “AJW”, and he denies everything – even his paper’s statement that he “assessed” the biopsies. All he did, he told GMC counsel, involved “looking over” pathologists’ shoulders “to learn”.
Which leaves “AA”. This was Andrew Anthony, now at the Hillingdon hospital, west London. At the time, he was a trainee - as he was eight years later - and the Legal Services Commission says he received £57,000 for assisting in Wakefield’s MMR assault.
So let’s clear this up. Was it one junior doctor who made the “histological findings” that helped to snag those tasty authorships in the Lancet? Or, as with the Loch Ness Monster, did everyone know someone who vouched for the observation, but nobody actually saw it themselves?
 Deer B. Pathology reports solve “new bowel disease” riddle. BMJ 2011;343:d6823.
 Wakefield AJ, Murch SH, Anthony A et al. Ileal lymphoid nodular hyperplasia, non-specific colitis and pervasive developmental disorder in children. Lancet 1998; 351:637-41 [retracted].
 Deer B. Wakefield’s “autistic enterocolitis” under the microscope. BMJ 2010; 340:c1127.
 Dhillon AP. Re: Pathology reports solve “new bowel disease” riddle. [electronic response]. BMJ 343;doi:10.1136/bmj.d6823
 Legal Services Commission. Freedom of Information response to Brian Deer. December 22 2006. http://briandeer.com/wakefield/legal-aid.htm
Competing interests: My investigation led to the GMC hearing and retraction referred to here.
What hasn't been elucidated fully so far is the meeting at the Royal Free where the final pathology for the Lancet information was submitted.
Professor Simon Murch gave sworn testimony at the General Medical Council 1 (GMC – Day 113 Friday 16 January 2008 Pages 43/44)to the following.
Which clearly emphasises the broader context of the decision making. Which some readers may have confused as being either John Walker-Smith's or for that matter Andrew Wakefield's.
Counsel Q Was there any meeting about the histology section?
Murch A Yes, I recall a meeting. I suspect that I may not be alone with that, but I do have a very good recollection of the meeting.
I think the reason was initially that Dr Davies had seen the draft of the paper and just wondered whether the description of the histology perhaps oversold it.
In other words, was the description in the paper something that was rather more florid than the lesion she remembered and thus my recollection is that she arranged a lunchtime meeting – I believe it was Friday, that is possibly irrelevant – in the manner of our normal histology meeting in the same place, in the histology seminar room, where the various pathologists who had seen the tissues attended at the same time and so this would be from the paper Dr Anthony —
Q I want to run through a list of names and then if I miss out anyone then of course add them in. Let us start off with Dr Davies; was she present at that meeting?
A She was indeed.
Q Professor Walker-Smith?
Q Dr Thomson?
Q Obviously yourself.
Q Dr Andrew Anthony?
Q Dr Dhillon?
Q Dr Heuschkel?
A I believe that Dr Heuschkel was present, yes. I am less certain about that, but that is my recollection from that meeting.
Q Dr Casson?
A I believe so, yes.
Q Dr Malik?
A I also believe so, yes.
Q Dr Wakefield?
Q Are there any others you remember being present at that meeting?
A I think Dr Alan Phillips may have been there as well but I cannot recall with certainty.
Q Were the original histology slides that had gone to Dr Davies’ lab looked at at that meeting?
A They were.
Q What was the outcome of that meeting about the description of the histology?
A That all the pathologists present when the slides were reviewed case by case agreed that the wording in the paper – we had a table of the histological findings, which I believe will be as seen in the paper here – they all agreed that the wording was reasonable. So I think that Dr Davies was then satisfied that the paper could go forward for publication without change in the histological description.”
Professor Dhillon emphasised in his response the need to take all clinical aspects and information into account in the final determination.
There was the clear opportunity to debate, to argue for and against they came to collective decision.
There can be no doubt that this was a highly skilled professional team, particularly in regards to this issue, the discovery and definition of a new and important disease pathology associated with children with ASD.
Competing interests: Father of ASD Son. Family fully vaccinated. No association placed on son's Autism and vaccines.
Forgive me for asking, but in view of Dr Dhillon's measured and dignified Rapid Response below, which makes it very clear the biopsy slides he was asked to review also contained slides from 'control' samples, i.e. from children with perfectly normal guts, I would like to know how the BMJ Editors and peer reviewers can state with certainty that ALL of these 61 unsigned and undated tick box sheets, actually relate to the Lancet 12 children?
Dr Dhillon states:-
"The online grading sheets represent an incomplete record of my observations of the slides of gut mucosal biopsies from patients who were included in the Lancet 1998 study, and there were “normal control” biopsies as well; however:
-Of those grading sheets attributed to me not all are mine (grading sheets on p38-47 and p55-64 inclusive of the BMJ Nov 2011 online document belong to someone else: NB the handwriting is different to mine)"
Only Dr Wakefield knew which biopsy slide number referred to which child, and I doubt very much whether Dr Wakefield or his lawyers would have availed the GMC prosecuting lawyers of this information before the GMC hearing.
Dr Godlee states in her response (below):-
"The BMJ is not and never has been in contact with the patients or their families to the extent that, apart from one parent who has written to us, we don't know their identities."
So please tell us Dr Godlee. How do you know the children reviewed in these numbered sheets are the same children referred to in the 1998 Wakefield et al Lancet study?
Competing interests: Autistic Grandson, diagnosed and treated for Ileal-Lymphoid-nodular hyperplasia (which he STILL has) at the Royal Free Hospital, London under the excellent of care of Professor Walker Smith and his team. 1998-2002.
It is both a pleasure and a humbling experience to acknowledge your very fine, respectful and dignified reply to an issue fraught with controversy.
I appreciate the personal and professional courage that this statement must have needed before being penned and submitted.
This is a fine example for younger colleagues to take clear note, for sometimes it is a more difficult road to travel.
Competing interests: I am the father of an ASD child. I have never associated vaccines with my son's condition. My family and I are all vaccinated on time and schedule.
A personal statement by Amar Dhillon in response to “Pathology reports solve “new bowel disease” riddle” (BMJ 2011;343:bmj.d6823). This statement is not a formal representation of UCL’s position.
The reappearance (BMJ Nov 2011 online: http://www.bmj.com/highwire/filestream/536428/field_highwire_adjunct_fil... ) of some of my histology grading sheets for the Lancet 1998 study (Wakefield AJ et al. Ileal lymphoid nodular hyperplasia, non-specific colitis and pervasive developmental disorder in children. Lancet 1998;351:637-41) is interesting. I have not seen the grading sheets since 1997-98 when I gave them to Andy Wakefield. Following the interest shown in the grading sheets in the November 12 2011 BMJ Feature “Pathology reports solve “new bowel disease” riddle” (BMJ 2011;343:bmj.d6823), accompanying articles and editorial it is evident that there are a number of misunderstandings. Many of these are a result of a lack of understanding of the essential difference between the systematic documentation of specific microscopical features in a grading sheet by a “blinded” (ie in the absence of any clinical, or other information) pathologist on the one hand; and on the other hand concluding an overall clinicopathological diagnosis by integration of clinical information with diverse lines of investigation (including information in the grading sheet). The difference between the two activities should be understood better.
The online grading sheets represent an incomplete record of my observations of the slides of gut mucosal biopsies from patients who were included in the Lancet 1998 study, and there were “normal control” biopsies as well; however:
-Of those grading sheets attributed to me not all are mine (grading sheets on p38-47 and p55-64 inclusive of the BMJ Nov 2011 online document belong to someone else: NB the handwriting is different to mine)
-The boxes with assigned patient “case numbers” on the grading sheets have been put onto the grading sheets by someone else (ie “child 1”, “child 2” etc): this information was not available to me at time either of the slide review or Lancet 1998 publication
-Neither the clinical details per case, nor the original diagnostic histopathology reports were available to me at the time of my review of slides
-At the time of my review I had been told that slides of study cases were mixed with “normal” controls: which slides were of study cases and which were controls was unknown to me.
My research review of the slides in 1998 has important differences with the routine diagnostic histopathology process:
-Routine diagnostic histopathology is done with knowledge of individual patient’s clinical details as far as they are available at the time of diagnostic reporting, and so the rendering of a diagnostic histopathological opinion in this situation is usual and appropriate (in direct contrast to the situation that pertains in a blinded research review)
-Then there is a joint review by clinicians and pathologists to evaluate the significance of the microscopic observations in the light of additional clinical, endoscopic, radiologic, and laboratory data that has been obtained after the “diagnostic” biopsy has been reported
-It is not unusual for the clinical significance of microscopic observations to be reinterpreted and altered by this process, and it could be that the histological diagnostic interpretation subsequently has to be corrected.
Thus the purpose of my grading sheet observations in 1998 was not, could not have been, nor was it intended to conclude the final diagnostic assignment of colitis (which has to be made in the light of full clinical/endoscopic/radiologic/ laboratory data; and response to treatment)
-Therefore on the grading sheets “nonspecific” means: “this microscopical appearance doesn’t remind me of any particular disease entity”, and this is why in none of my grading sheet observations have I stated “colitis”.
Bowel disease is not diagnosed by gut mucosal histopathology in isolation:
-I am of the opinion that the histological interpretation should never (or not very often) replace clinical judgement
-“A final diagnosis can only be made with the full clinical information and a biopsy specimen should be reported as diagnostic only if full supportive clinical information is available.” (Jenkins D et al. Guidelines for the initial biopsy diagnosis of suspected chronic idiopathic inflammatory bowel disease. The British Society of Gastroenterology Initiative. J Clin Pathol 50,93-105;1997).
In 1998 there was no paediatric gastrointestinal pathology literature to refer to for guidance regarding ileal and colonic mucosal biopsy microscopical appearances and their interpretation or significance in autistic children. In 1998 the series of cases in the Lancet paper was unusual, if not unique, and it was one of the aims of the study to explore the significance or otherwise of the subtle histological changes in autistic children with gastrointestinal symptoms. Prejudgment of the significance or otherwise of the histological changes in isolation in the 1998 study cases would have been inappropriate previously, and remains so now.
-Several expert gastrointestinal pathologists and gastroenterologists have commented on the grading sheets (BMJ Nov 12 2011) and they have stated that the findings cannot be colitis; however:
-It is a mistake to apply uncritically adult gastrointestinal biopsy histopathological thresholds of normality vs abnormality to children
-The expert gastrointestinal pathologist and gastroenterologist commentators have tried to assess the diagnostic implications of data represented in histopathological grading sheets alone
-This is a fundamental mistake: the significance of the histopathological component of any diagnostic equation depends on consideration of the histopathology within the complete clinical context
- The current opinions of the experts regarding the significance of the histology grading sheets are subject to retrospective bias by knowledge of events since 1998.
At the time of submission of the Lancet 1998 publication I had the clinical, laboratory, endoscopic and histology information presented to me in summary tabular form, and aggregated descriptive text only.
-My grading sheets were with Andy Wakefield and my general recollection of my impression of my slide review was that some biopsies were a bit inflamed, and others were not: I did not know which case was represented by which set of slides, and which sets of slides were “normal” controls. As far as I recall, the changes were not severe in any of the slides, but it is not unusual for gut mucosal biopsies to show little abnormality even in clinically well defined cases of gastrointestinal disease, particularly in children
-My clinical colleagues had collated all of the available information, including my microscopical grading sheet observations in the context of their knowledge of each patient’s condition and concluded a final diagnosis of colitis when this was considered by them to be appropriate
-Thus, at the time of submission of the Lancet 1998 publication, with the limited supplementary information available to me (which I had been prevented deliberately from knowing during the study); and in the context of a comprehensive clinicopathological review by trusted clinical colleagues, the designated diagnosis of colitis seemed to me to be plausible.
Competing interests: I am a co-author of: Wakefield AJ et al. Ileal lymphoid nodular hyperplasia, non-specific colitis and pervasive developmental disorder in children. Lancet 1998;351:637-41
Dr Godlee says "The second point is that, even if we had concluded that we were obliged to obtain consent, we reasonably anticipated that we would have been unable to obtain it." She goes on to say "...we reasonably believed that even if we could establish contact with the patients or their families, we would not obtain consent."
Lets forget about the MMR - this is a truly extraordinary statement, of intent and about integrity, and potentially takes us into the territory currently being explored by Lord Leveson. If Dr Godlee works by the principle that if consent is likely to be refused, then it is fine to dispense with consent, then the time has surely come to look not just at research integrity, which is undoubtedly necessary, but also at journalistic integrity. Or should she change the title of her publication - I believe that the name NOTW has recently become available in the UK.
Competing interests: No competing interests
I note that Fiona Godlee  gives a less full disclosure here than in her accompanying editorial which concludes with the statement: "the BMJ Group receives funding from the two manufacturers of MMR vaccine, Merck and GSK" .
Further I would point out that readers of BMJ may be at a disadvantage in assessing the information in front of them if they have not seen a report on Nature.com , also reproduced in Scientific American . In it Prof Bjarnason is reported as saying:
"he doesn't believe they [the new materials] are sufficient to support claims in the Lancet paper of a new disease process. He also questions whether "non-specific" on the grading sheets refers to colitis, saying it could refer to any kind of gut changes. But he says that the forms don't clearly support charges that Wakefield deliberately misinterpreted the records. "The data are subjective. It's different to say it's deliberate falsification," he says."
Mr Deer states:
"he never accused Wakefield of fraud over the interpretation of pathology records"
and Dr Godlee herself is reported as saying:
"that the journal's conclusion of fraud was not based on the pathology...".
As to Dr Godlee her statement here:
"The second point is that, even if we had concluded that we were obliged to obtain consent, we reasonably anticipated that we would have been unable to obtain it."
is surely of the sort that you proverbially frame and put above your mantelpiece.
 Fiona Godlee, 'Response to Adam Jacobs" http://www.bmj.com/rapid-response/2011/11/15/re-pathology-reports-solve-...
 Fiona Godlee, 'Institutional Research Misconduct', BMJ 9 November 2011 http://www.bmj.com/content/343/bmj.d7284
 Eugenie Samuel Reich, 'Fresh dispute about MMR 'fraud'', http://www.nature.com/news/2011/111109/full/479157a.html?s=news_rss
 Eugenie Samuel Reich, 'Discredited Vaccine-Autism Researcher Defended by Whistleblower Group', http://www.scientificamerican.com/article.cfm?id=discredited-vaccine-aut...
Competing interests: Autistic son
Thank you for raising the issue of consent for publication of the pathology grading sheets.
We did not obtain consent for publication in this case. In deciding to take this course we took into consideration our own patient confidentiality policy, advice from our ethics committee, relevant law, the interests of the patients in question and the public interest in the publication of the grading sheets. Having weighed all these considerations, we concluded that the right thing to do would be to publish the grading sheets, specifically to enable readers and the wider public to test and judge for themselves the merits of the competing arguments put forward by David Lewis, Brian Deer and the reviewers based upon the contents of the grading sheets.
In terms of how we went about carrying out this balancing exercise, the first point to observe is that the patients in question are not identifiable from the grading sheets as published, certainly no more so than they already were in consequence of the public GMC proceedings involving Andrew Wakefield and John Walker-Smith and the media coverage of the case. We specifically obscured the patients’ hospital numbers given on the sheets to ensure that this was so. Provided that living individuals are not identifiable in material that we are considering for publication, there is no obligation to obtain consent, whether as a matter of our own patient confidentiality policy (http://www.bmj.com/about-bmj/resources-authors/forms-policies-and-checkl...) or the law (i.e. the Data Protection Act).
The second point is that, even if we had concluded that we were obliged to obtain consent, we reasonably anticipated that we would have been unable to obtain it. The BMJ is not and never has been in contact with the patients or their families to the extent that, apart from one parent who has written to us, we don't know their identities. Furthermore, given (a) the fact that most of the families of the patients in question are known to be dedicated supporters of Andrew Wakefield and opponents of Brian Deer and his work and (b) the tenor of the articles that we were proposing to publish alongside David Lewis’s letter, we reasonably believed that even if we could establish contact with the patients or their families, we would not obtain consent.
Third, we considered that there was an overwhelming public interest in publication of the grading sheets and the data they contained, most particularly for the reason given above. With respect to the issue of public interest, it is also worth bearing in mind the circumstances in which the grading sheets came to our attention in the first place. As you are aware we were sent the grading sheets by David Lewis who had been given them by Andrew Wakefield. We reasonably took the view, having regard to our communications with David Lewis, that the grading sheets were likely to be published by him on the National Whistleblower Center website and quite possibly more widely in support of an ill-founded and misinformed campaign to exonerate Wakefield, undermine the BMJ’s work in exposing Wakefield's research misconduct, and thereby to further mislead the public about the validity of Wakefield’s research. Having in mind the whole sorry history of the MMR scare, we were in no doubt about the damage that such publication might cause if left unanswered. In order to answer Lewis’s argument with the cogency it warranted, we felt we had no option but to publish the grading sheets at the heart of the debate.
Competing interests: I am the Editor of the BMJ and responsible for all it contains