Sunday, December 19, 2010

Anonymous Criticism - Defending Ernst

maskImage via WikipediaAs with most bloggers who allow it I have received a variety of comments on my last blog, The self-importance of being Ernst.  Generally it is my policy not to allow anonymous comments.  Since I have the courage to identify myself in the blog I think anyone wanting to comment should do the same.  Maybe that's my self-importance or it is my belief that one should have the courage of ones convictions. 

Someone submitted a few comments in defense of Ernst to my blog and given that the email address is their web site and that their web site, which is just a tirade about various CAM methods, does not allow any commentary moderated or not from their readers I choose not to provide him/her with the links, i.e. advertising.  However, I won't hide behind my ability to block a comment and will paste each of the comments and I'll reply.  If my anonymous critic comes out from behind the curtain I might then publish as-is the words of this Wizard of Oz :)

Criticism 1

I noted in my previous blog posting that it was...unusual for Ernst to have a copy of Long's pre-submitted testimony, which was rejected by the CT Board of Chiropractic Examiners.  My anonymous critic says:
If you read the ‘Methods’ section of Professor Ernst’s original paper he said that “several experts were also contacted for further data”. Perhaps that is how he managed to see Preston Long’s document.
Well that would be reasonable except that, Long doesn't fit any one's definition as an expert.Secondly one needs to keep in mind that Ernst was conducting a "systematic review".  In a systematic review it is not uncommon to seek from other researcher, AKA experts their bibliographies of appropriate literature.  Clearly Long isn't a researcher on the topic (or any other that I can tell).  And one must remember that the data that Ernst was contacting others for was more papers in the scientific literature.  See a larger quote from the Methods:
In addition, our own departmental files and the bibliographies of the articles thus located were searched. Several experts were also contacted for further data.
Criticism 2
Stephen Perle wrote: “What is the common feature of Ernst's citation of these deaths whose information or rather misinformation was obtained from a web site and the deaths reported by Long? Neither of these data sources were from the scientific literature. In his reply to our letter Ernst says "These cases were, however, merely added for completeness and not included in my total number of 26 cases reported in my review." Completeness? So adding people who didn't die after chiropractic spinal manipulation and weren't in the scientific literature adds completeness to a review of the scientific literature?”

Note that Professor Ernst said in his Introduction that:

“A responsible approach to serious therapeutic risks, however, requires an open discussion of the facts. In this review I aimed to provide the basis for such a discussion by summarising all fatalities which occurred after chiropractic spinal manipulation and were published in the medical literature.”

Note that he didn’t say he would *exclusively* look at the medical literature. Indeed, in the Methods section he was more specific, informing us that

“Electronic searches were conducted in the following electronic databases: Medline, Embase, AMED, Cochrane Library (September 2009)… *In addition*, our own departmental files and the bibliographies of the articles thus located were searched. Several experts were also contacted for further data. Case reports were included if they provided information on human patients who had died after receiving one or more treatments from a chiropractor.”

He goes on to say that many other fatalities seemed to have remained unpublished and gives examples of the testimony of Preston Long DC (whom it is likely that he contacted personally) which listed the family names of nine victims. Dr Long also stated that ‘many others are unknown hidden behind legal agreements of silence’. Professor Ernst then cites ‘names’ of further North American fatalities from the website www dot whatstheharm dot com
Well this isn't exactly true.  The purpose says: "In this review, I aimed to provide the basis for such a discussion by summarizing all fatalities which occurred after chiropractic spinal manipulation and were published in the medical literature." Well the problem is my anonymous critic is grasping at straws.  The purpose of looking in the departmental files or contacting experts are to find other papers in the medical literature that the search failed to find.

IF Ernst had a purpose that included all possible sources of information then that would have been in his methods.  As I noted earlier if Ernst had put the information from Long in his discussion to coincide with the assertion that many cases are remain unpublished I would have only commented on the apparent collusion with critics of chiropractic not the propriety of including Long's "testimony".

My anonymous critic goes on to note the Ernst cites the names of other American fatalities found on the web site (cited above).  Except that 5 of the 9 deaths that Ernst attributes to chiropractic spinal manipulation (in that paragraph of his paper but not in the total death count) did not die as a result of chiropractic spinal manipulation.  So again if Ernst had only talked about these deaths to buttress his argument that the literature lacks a presentation of all deaths after chiropractic spinal manipulation I would not have criticized his lack of following his own purpose.  But then again would have criticized his zeal to attribute all the deaths found on the web site to chiropractic spinal manipulation. 

Criticism 3
Stephen Perle wrote: “Wenban has detailed the commonality of wrongly ascribing adverse events of manipulation to the care of doctor’s of chiropractic.”

As Professor Ernst says in his response to Whedon et al, his original review contests that with good references. He also says he can not reasonably be expected to know of the ‘personal correspondence’ that Wenban and Bennett cited and asserts that the small discrepancies in numbers (about which they argue) are almost irrelevant.
You know if we were talking about hundreds or thousands or even hundreds of thousands of deaths one or two discrepancies wouldn't matter would they?  But and this is the amazing fact we are talking about a very small number - 26.  So adding one that doesn't belong is big.  I mean with a total of 26 in 115 years we are talking a 3.8% error.  OK the number is a small point - it just goes to the sloppy nature of the review.  Add a couple take away a couple and pretty soon you got nothing of substance in Ernst's "systematic review".
Criticism 4

Stephen Perle wrote: “Ernst says Cassidy's study has been repeatedly criticized for being flawed. The key word is repeatedly. This obviously repeatedly means more than once, which means that there must be more than one reference cited for that criticism. In fact, I think most would agree that repeatedly probably means many more than one. Well there is only one reference cited and what is that: Ernst E. Vascular accidents after chiropractic spinal manipulation: myth or reality? Perfusion 2010; 23: 73–4. No it can't be the only criticism in the scientific literature (not the blogosphere mind you - this is science we are talking about here) that Ernst can find is his own (now you get the idea about the title for the blog).”
Professor Ernst did not qualify where the study had been repeatedly criticised. Further, it you’re going to discount the blogosphere, then your blog post here should not, in any way, be taken seriously by the scientific community.
Well actually Ernst did qualify where the study had been repeatedly criticized.  He provided ONE reference to the journal he is the editor-in-chief of.  Since I know that my anonymous critic isn't a scientist (I know this from their former blog name) I'll forgive his/her ignorance about citation (and purpose above).  However, given the fact that Ernst had no problem citing a web site as a source for the purported deaths, I am sure if his source for "repeated criticism" of Cassidy was the blogoshere or other web sites (even my anonymous critic's) there's no reason to suppose he wouldn't cite them.  The fact of the matter remains that there have been no substantive criticism of Cassidy's methods in the scientific literature.  There has been only one letter to the editor by Maigne. It is my opinion that Cassidy et al adequately responded to Maigne but clearly there isn't "repeated criticism" nor criticism substantive enough to deal a death blow to the validity or importance of Cassidy's findings. 

I think one of the most important points one needs to keep in mind regarding cervical manipulation and stroke is that the only people going ape about this issue are critics of chiropractic.  It just isn't an issue to epidemiologists nor any of the stroke associations.  For example I was at a conference this year in Connecticut put on by the Connecticut Department of Public Health and the American Stroke Association on stroke in the young adult.  Not one speaker mentioned cervical manipulation the whole day.  The critical problem when it comes to stroke in the young adult is that despite its prevalence many health care providers don't recognize the condition because they think stroke is a condition of older people.  Here are the stats I heard for strokes in CT for 2009, keep in mind the population of CT is about 3.5 million

                Age          Number of deaths
45-65             2047
25-44               354
15-24                 34
4-14                   10
<4                        8

Clearly stroke is a horrible event to occur to anyone young or old.  I know first hand from family members how devastating it is but right now the evidence just does not support a causal relation between cervical manipulation and stroke.

Finally I agree completely with my anonymous critic that no one in the scientific community should take my blog or any other blog seriously from a scientific stand point.  That is why I didn't post anything on this blog until my letter to the editor was published.  As I noted in the previous posting the way science progresses is not only the publishing of ones results but that there is an opportunity for critique in the same venue via letters to the editor.  The more scientifically minded should read Ernst's paper, the letters to the editor and his response.  In fact it is this reason that I have not posted my anonymous critics comments as is.  Because I don't want to encourage people to see this person's opinion without the opportunity for rebuttal.  If they posted their name and not their URL I would have not written a whole blog post and just let the comments go and commented on them as I have done herein.

Criticism 5
Stephen Perle wrote: “Now to his critique. I won't reproduce it here…”

Why not? For anyone wishing to read it, there’s a link to the full text of it in the chiropractic section of my website. It really is quite revealing.
Well the simple answer is I don't violate copyrights.  The paper is copyrighted and neither my anonymous critic nor the other web site where I found the paper have anything about permission granted  from the copyright holder to publish the paper on the web.  The journal nor Ernst on his web site have a PDF available for free.  I guess if one is really agitated about the chiropractic profession it is acceptable practice to violate copyrights.  Zealotry trumps legality.

Also. I suggested that it is far better for people to listen to the cross-examination of Dr. Cassidy at the hearing that Long never came to.  Again here is a link to the CT-N video of Cassidy's half day on the witness stand.  Every point Ernst made and then some were tried by the two attorneys who cross-examined Cassidy.  Hear the answers from the horses mouth. 

Criticism 6
I think readers should be told that Dohos and Tragiannidis, of the Aristotle University of Thessaloniki’s Medical School in Greece, wrote to the International Journal of Clinical Practice in support of Ernst’s paper:

“…we agree with Professor Ernst on the following points

• Vascular accidents after upper spinal manipulation can cause severe vertebral artery dissections;
• Numerous deaths have been associated with chiropractic neck manipulations;
• Many other cases are unknown behind legal agreements of silence
• Therefore the risks of chiropractic neck manipulations by far outweigh their benefits.”

Ref: Critique of review of deaths after chiropractic, 3. Dokos C, Tragiannidis A.
Int J Clin Pract. 2011 Jan;65(1):103-4.
The problem with  Dohos and Tragiannidis is that they provide no substantive evidence for any of their bulleted opinions above.   

Criticism 7 
I also think readers should be made aware of the following in the US:

"The National Quality Forum lists 28 ‘never events’ healthcare mistakes that should never happen and need to be reported. Death or serious disability from spinal manipulation is listed as no.16. But chiropractors do not have to report this because they have a loophole. The National Quality Forum demands it of clinics and hospitals but no reporting is mandated for individual doctor's offices where 99% of spinal manipulation is done. Chiropractors generally do not practise in hospitals or clinics."
Ref: Britt Harwe, open letter to the Editor, Focus on Alternative and Complementary Therapies, Volume 15, Issue 1, pages 87-88, March 2010.
OK and the point?  There are a lot of events that occur in private practices for which no reporting is mandated. 

In conclusion I am waiting for the wizard of oz to step out from behind the curtain or not. 


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