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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Thursday, December 16, 2010

The self-importance of being Ernst

Oscar Wilde memorial, Dublin, Ireland.Image via Wikipedia
Some may know Oscar Wilde's play The Importance of Being Earnest from which I've modeled the title of this blog entry.  The play is a farce where obligations are shirked by assuming false identities.  There is no discussion of false identities in this blog but there is a false presentation of objective science on the part of Dr. Edzard Ernst as Wilde writes in Act 1
 I don’t play accurately – anyone can play accurately- but I play with wonderful expression.
In July the International Journal of Clinical Practice published a paper by Dr. Ernst titled: "Deaths after chiropractic: a review of published cases."  When I read the paper I noticed some obvious errors.  As opposed to some so-called science bloggers, rather than blog about it, I scienced.  (I read once where a scientist said that one should use science as a verb, one sciences.)  
I understand that Web 2.0 allows anyone to be a critic and possibly have great influence on public opinion (gee I am writing a blog about this).  However, one of the fundamental differences between the scientific endeavor and other domains of thought is that knowledge progresses though the publishing of ones findings in a public forum after peer review and then subject to the possibility of letters to the editor which help clarify or critique or add information to that publication.  When one submits a letter to the editor they are peer reviewed, as were the original manuscripts, and if one is using a bibliographic database such as PubMed the letters to the editor are hyperlinked to the record for the original manuscript so that people can find these important commentaries.

Here is a link to our letter to the editor on PubMed's web site.  Copyright issues prevents me from providing the letter to my readers.  We initially wrote a much longer letter but were informed after submission that the journal's maximum size is 500 words for a letter.  I will provide the added detail in this blog.
The paper the letter is in regard to is: Ernst E. Deaths after chiropractic: a review of published cases. Int J Clin Pract. 2010 Jul;64(8):1162-5.  In this paper Ernst's purpose was 
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.
In the results section of the paper he has a paragraph that is, to say the least, very interesting when one thinks of the purpose.   Herein he describes "the testimony of the chiropractor Preston Long for a court in Connecticut recently listed the family names of nine victims."  Ernst cites this with: "Presentation by Dr Preston Long DC to State of Connecticut. Connecticut State Board of Chiropractic Examiners. Hartford Connecticut.
25 October 2009.  There was never a hearing before the State Board of Chiropractic Examiners on October 25, 2009.  The hearing was in January of 2010 and because Long did not appear to under oath attest to his pre-submitted testimony it was, in accord with the procedural rules in CT not accepted and thus not part of the public record.  One wonders how does Ernst get this document when it was not public.  I have a copy as I was on the witness list and these pre-submitted testimony documents I was told were not to be made public until the board hearing.  

Anyone wishing to see the hearing where Long's testimony is discussed should go to the CT-N web site here.
In that same paragraph Ernst cites nine deaths from chiropractic  spinal manipulation that he found on a web site.  When I read Ernst's paper one name stood out in my mind, Kimberly Lee Strohecker.  I know a fair bit about Ms. Strohecker's very unfortunate death.  I wrote about it in a 2004 ethics article titled J'Accuse...! (I Accuse).  This article is about the death of Ms. Strohecker after a chiropractor got her to stop taking her anti-seizure medication.  At least the federal court barred the chiropractor from ever practicing chiropractic again along with prison and a fine.

Yes her death was the result of a chiropractor's actions but they weren't due to chiropractic spinal manipulation.  So I reviewed all the other people Ernst cited as dying from chiropractic spinal manipulation on the web site and discovered the Ms. Strohecker was one of 5 whose death might have been because of a chiropractors actions but weren't the result of chiropractic spinal manipulation.

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?

Now some reading this will say - gee that's picky.  Well the point is ones method must fit ones stated purpose.  Now if he had said in the discussion that there may be many more deaths after chiropractic spinal manipulation that aren't reported in the scientific literature and then cited these he would have at least stood on safer ground.  Still 5/9 cases he said were after chiropractic spinal manipulation weren't.  As we noted in our letter to the editor: "When obvious facts are wrong, the veracity of other facts, not as easily verified, must come into question."  Science works in part because we have to have faith that what people write in their papers is in fact the truth.  It is not truthful to say 9 people died when only 4 did.  Thus can we trust the rest of what Ernst tells us?

Also Ernst cites an event that never occurred, Long's non-testimony before the CT Chiropractic Board.  So again he cites something that is obviously not true.  Thus can we trust the rest of what Ernst tells us?  Some might say it is an honest error which if he was a newbie to scientific publishing I'd say give him a pass but I just did a PubMed search for Ernst E and found 1426 papers.  I don't think he can claim to be a newbie.

Ernst cites a paper by Dziewas et al as presenting another case of a person who died after chiropractic spinal manipulation.  However, one of the great features of modern electronic bibliographic searching technologies, such as  PubMed, which Ernst used, is that letters to the editor also are found with the citation for every paper.  When searching PubMed for Dziewas one finds a letter to the editor by Wenban.  Wenban reported that the treatment was not provided by a chiropractor and thus cannot be chiropractic spinal manipulation.  Wenban has detailed the commonality of wrongly ascribing adverse events of manipulation to the care of doctor’s of chiropractic. 
A couple of the letters to the editor note that Ernst missed in his discussion the study by Cassidy et al that investigated the association between stroke and seeking care of a chiropractic physician or a medical physician and found no excess risk for seeking care with a chiropractic physician.  I've blogged about this previously.   In Ernst's reply he says about Cassidy's study "it has been repeatedly criticised for being seriously, perhaps even fatally, flawed e.g. (8). The ‘inconvenient truth’ might thus turn out to be a 'convenient untruth’."  A long time ago I read an article that talked about somethings one can do to simply determine the validity of a paper one reads.  One of those is references.  Above 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).  Anyway, you mean to tell me that none of the critics of this study had the testicular fortitude to write a letter to the editor?  Cassidy's study was published in Spine and was part of the WHO's Bone and Joint Decade's Cervical Spine Task Force reports.  Well OK Ernst didn't see fit to write his critique in the journal it was published in, as my colleagues and I did about Ernst's paper.  You know those newbies to scientific publishing don't know that you should submit critiques to the journal it was written in.  Well you remember those 1426 citations to Ernst in PubMed just 204 are letters to the editor.  OK but let's look at his cited critique.  
Ernst E. Vascular accidents after chiropractic spinal manipulation: myth or reality? Perfusion 2010; 23: 73–4.
Don't search too hard for this in PubMed.  It's not there. The journal name is wrong.  I know newbies sometimes get their citations wrong especially when they don't know the journal too well.  Here is the proper citation.
Ernst E. Vascular accidents after chiropractic spinal manipulation: Myth or reality? Verlag Perfusion GmbH. 2010;23:73-4.
What do I know about Verlag Perfusion GmbH.  If you look at their web site you'll see it is a German publication and the first editor listed is...Ernst.  So I guess he's unfamiliar with the proper name for the journal.
Now to his critique.  I won't reproduce it here but instead suggest listening to Cassidy answer these questions as they were posed to him before the CT Chiropractic Board you can see his testimony here.
Ernst in his paper on deaths after chiropractic spinal manipulation also says that there is no benefit to spinal manipulation.  What's his reference for that.  You guessed it, his own narrative review.  Thus he ignores a growing body of systematic reviews showing benefit to spinal manipulation (1- 9)

There is one more item.  In that list of 1425 papers in PubMed written by Ernst E there are 299 systematic reviews of these I count 37 which there is only one author.   Of the 299 systematic reviews 17 are about the chiropractic profession.  Has a real fixation on us doesn't he.  Of the 37 systematic reviews with only one author 10 are about chiropractic.  Or to put is another way of the 17 systematic reviews about the chiropractic profession 10 are single author systematic reviews.  This is astounding.  Why?  Because standard practice in systematic reviews is to have at least two people.  What is considered to be the preeminent international group conducting systematic reviews, The Cochrane Collaboration never does any reviews with one reviewer.  Its just not done by almost anyone but...Ernst.  In fact from the Cochrane Handbook:
It is essential that Cochrane reviews be undertaken by more than one person. This ensures that tasks such as selection of studies for eligibility and data extraction can be performed by at least two people independently, increasing the likelihood that errors are detected. If more than one team expresses an interest in undertaking a review on the same topic, it is likely that a CRG will encourage them to work together.
 Well the self-importance of being Ernst is that he's the only expert whose opinion counts to Ernst.


  1. Oliphant D. Safety of spinal manipulation in the treatment of lumbar disk herniations: a systematic review and risk assessment. J Manipulative Physiol Ther. 2004 Mar-Apr;27(3):197-210. Pubmed record
  2. Fernandez-de-Las-Penas C, Alonso-Blanco C, Cuadrado ML, Pareja JA. Spinal manipulative therapy in the management of cervicogenic headache. Headache. 2005 Oct;45(9):1260-3. Pubmed record
  3. Chou R, Huffman LH. Nonpharmacologic therapies for acute and chronic low back pain: a review of the evidence for an American Pain Society/American College of Physicians clinical practice guideline. Ann Intern Med. 2007 Oct 2;147(7):492-504. Pubmed record
  4. Hawk C, Khorsan R, Lisi AJ, Ferrance RJ, Evans MW. Chiropractic care for nonmusculoskeletal conditions: a systematic review with implications for whole systems research. J Altern Complement Med. 2007 Jun;13(5):491-512. Pubmed record
  5. Bronfort G, Haas M, Evans R, Kawchuk G, Dagenais S. Evidence-informed management of chronic low back pain with spinal manipulation and mobilization. Spine J. 2008 Jan-Feb;8(1):213-25. Pubmed record
  6. Hurwitz EL, Carragee EJ, van der Velde G, Carroll LJ, Nordin M, Guzman J, et al. Treatment of neck pain: noninvasive interventions: results of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders. Spine. 2008 Feb 15;33(4 Suppl):S123-52. Pubmed record
  7. Bronfort G, Haas M, Evans R, Leininger B, Triano J. Effectiveness of manual therapies: the UK evidence report. Chiropr Osteopat. 2010;18:3. Pubmed record
  8. Gross A, Miller J, D'Sylva J, Burnie SJ, Goldsmith CH, Graham N, et al. Manipulation or mobilisation for neck pain: a Cochrane Review. Man Ther. 2010 Aug;15(4):315-33. Pubmed record
  9. Miller J, Gross A, D'Sylva J, Burnie SJ, Goldsmith CH, Graham N, et al. Manual therapy and exercise for neck pain: a systematic review. Man Ther. 2010 Aug;15(4):334-54. Pubmed record
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Wednesday, October 20, 2010

The Vaccine Song

MIAMI - NOVEMBER 03:  Marina Spelzini, a regis...Image by Getty Images via @daylife Today I saw this web site that has a country song about vaccines.  The Vaccine Song

The song writer did a great job of hitting on all the issues in the vaccine debate. There are also good links to other resources on the web for more information on the issues.  A few were new to me

What's the harm in vaccine denial?

The Truth About The Evils Of Vaccination

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Saturday, April 17, 2010

Science, sometimes - stroke and chiropractic

Louis XIV visiting the  Académie des sciences ...Image via Wikipedia

The Connecticut Board of Chiropractic Examiners ruled on the issue of informed consent.  There was a hearing on a declaratory ruling regarding informed consent and stroke.  The board heard four days of testimony (which are available as videos at CT-N).  Although the board's ruling hasn't yet hit the internet where I can find the exact text, it appears from newspaper reports that they ruled affirming that informed consent is the law in Connecticut but refused to require specific consent about a risk of stroke.  Both the New Haven Register and the Hartford Courant have weighed in on this issue and it appears that science isn't the strong suit for either newspaper.

Both papers believe that there is a risk of stroke from cervical manipulation.  Of course the two groups that advocated before the board for the ruling to require telling prospective chiropractic patients of the risk also believed there is a risk. To me what I have learned being part of this process is that science matters to many people only when it serves their interests. 

Nature of science

Science is an epistemological theory.  Epistemology is the study of how we acquire knowledge.  Science, as we know it, is just one method to acquire knowledge through what's called the scientific method.  Wikipedia's explanation of the scientific method is well done (at least today).  Simply, the method is to observe some phenomenon, create a hypothesis (i.e. a prediction) about that phenomenon, then test that hypothesis by controlled observation, an experiment. 

There are other epistemologies besides science.  For example divine revelation where knowledge comes from a deity. Some have called my profession, chiropractic a cult because there are some in the profession whose epistemology is based upon the work of a guru, typically BJ Palmer.  At one time most of medicine was based upon some guru's dogma.  For example anatomy was controlled by the works of Galen (1st - 2nd century of the common era) who really didn't have a clue what was in the human body - he'd looked at monkeys as human dissection wasn't allowed in his time. It wasn't until a skeptic Andreas Vesalius (16th century) applied the empirical method - noting that the bodies he dissected didn't look the way Galen said that anatomy progressed beyond the dogma of Galen.

One common epistemology is the use of anecdotes.  You know, "I once knew a guy who smoked a carton of cigarettes a day for 70 years and never got lung cancer.  So cigarettes are safe."  OK that's extreme but anecdotes have a tremendous hold upon our thinking and often it is very difficult to let science triumph when anecdote sits in contradiction of the science. Anecdotes which in health care publications are called case reports are very good at hypothesis generation, remember the scientific method is based upon an observation generating a hypothesis.  Case reports can help generate a hypothesis but never can validate the hypothesis.  I've heard it said often amongst skeptics of chiropractic that the pleural of anecdote is anecdotes not evidence.  I'll come back to this quote again!

Autism and Vaccinations

I know it looks like I'm completely switching gears but there is a logic to my digression.  As I have thought a lot about stroke and manipulation and autism and vaccinations I've come to see that they are analogous situations.  Think about this, a family has what appears to be a healthy normal baby.  They are in this blissful state of early parenthood enthralled with the baby who is developing a similar love for them.  Then suddenly the developing relationship on the babies side changes and the child becomes distant.  The parents seek advice and find that their now more withdrawn child appears to have autistic spectrum disorder.  To the parent this can be a devastating event. They want desperately to find a cure and if there isn't a cure (which there doesn't seem to be) they want to blame someone, something. This is only natural.  The parents feel as if someone, something has taken their child away from them.  Then they hear about a supposed link between autism and vaccinations.  Now they have people to blame.  They can blame the vaccine manufactures.  They can blame the government for trying to tell us that vaccines are safe. They can blame their doctors for giving their baby this poison which caused the problem.  To hear the anti-vaccination folks go on about autism and vaccines is to hear the voice of anger and vindictiveness.  They are not malicious people just untrained in the ways of science and prone to letting their emotions have greater sway over how they look at the evidence.

What about the evidence?  Those parents when confronted with the scientific evidence that does not support their belief that autism is caused by the vaccine, reject the evidence.  What is the basis for the rejection, valid critique of the science?  No, usually it is what comedian Stephen Colbert called truthinessTruthiness, which was the Merriam-Webster word of the year in 2006, is defined as: "Truth that comes from the gut, not books," and "The quality of preferring concepts or facts one wishes to be true, rather than concepts or facts known to be true."

Then a whole support industry develops around this belief.  There are organizations whose purpose is to advocate on behalf of the parents and spread the word that autism is definitively caused by vaccines.  This theory is advanced in such a way that reading the web one might believe it was the only one.

I was a participant in a webcast on vaccines for the California Department of Public Health titled "Wading through the Confusion".  As one of my colleagues on the webcast, David G. Amaral, PhD, an autism researcher from the UC Davis M.I.N.D. Institute lamented is that there is inadequate research money available to find the cause of autism because the theory advocated by these groups has so dominated the discussion.
[Any one wishing to know more about this battle should read Paul Offit's book Autism’s False Prophets: Bad Science, Risky Medicine, and the Search for a Cure. The NYTimes article on Offit is enlightening about the lack of civility of public discourse on this issue.] 

Back to Stroke

Now think about ischemic strokes.  Isn't this what happens after a stroke in a younger person.  I mean we sort of think of stroke as a disorder that affects the elderly and it is.  The CDC lists death from stroke as the third most common cause of death behind heart attacks and cancer.  The rate of stroke increases dramatically as one ages. Stroke is a life changing event that affects not only the person who may be disabled, but the entire family and other caregivers as well. Utility analyses show that a major stroke is viewed by more than half of those at risk as being worse than death. (1)

So a younger person, say in their 40s - 50s has a ischemic stroke.  That person and their family are going have the same desire as the family who finds their child has developed autism, find someone to blame.  Well instead of a radicalized group of parents spreading the word that vaccines are the cause for autism there is a radicalized group of patients spreading the words that it must be a visit to a chiropractor. This theory that chiropractic cervical manipulation is the cause of strokes in the young has become so common that many MDs speak as if this is an established fact.  They don't really know what the research says about stroke but couple their distrust of chiropractic (2) which I think is a result of the AMA's illegal boycott(3) and it's easy to see how they would assume the connection between chiropractic care and stroke is valid.  Plus why search the literature to find this out, most people they know will tell them it is true.  It seems scientific evidence doesn't always matter.(4)

What is the epidemiology of these strokes?  They are rare representing 2% of all ischemic strokes but 10 to 25 percent of strokes in the young and middle aged.(5)  These facts are not well known so when someone in who is young or middle aged presents to a hospital with a stroke everyone wants to know why.   Given the bias and bad information then the question comes, "did you see a chiropractor within the past month?"  This only serves to expand the perceived value of this belief.  It is not uncommon to hear someone say that the risk is proven.  Proof is a word I tell my students that they can never use when referring to biomedical research.  There is either evidence that supports or refutes a particular hypothesis.  IF they want PROOF then their career choice should become mathematics not health care. 

Or that there is 80 years of science backing this up.  Well time to go back to that earlier quote: "the pleural of anecdote is anecdotes not evidence."    There isn't an 80 year history of science with respect to the association between cervical manipulation and stroke, there is an 80 year history of anecdotes that appears in the scientific literature.  The real science behind this issue has a much shorter history.  We get a survey of neurologists in 1995 (6) with a very poor response rate and which suffers from referral bias. (7)  Plus a survey doesn't establish cause and effect.  There are many studies of cases that have tried to discover the incidence.  For example this paper by Haldeman et al which estimated that one chiropractor in 48 would during the course of their practice career would be made aware of an arterial dissection following cervical manipulation.  But none of these papers actually evaluated the risk. 

There are only three studies that have evaluated the risk of stroke after manipulation.  And all three agree there is an association.  (9- 11)  The first two found a risk (9, 10) and the third (11) finding the same association provided evidence that explains the first two.  Cassidy et al (11) used the same data sources as Rothwell et al (9) but Cassidy et al study investigated one thing neither Smith (9) nor Rothwell (10) did and that is they determined the background rate of these strokes.  The issue is if the rate of strokes after chiropractic care was greater than the background rate (those that were occurring spontaneously not caused by the manipulation) then we would know what the added risk was due to manipulation. The finding, the rate of strokes in patients under 45 seeking care from their primary care physician was identical to the rate for those who had seen a chiropractor.  Thus seeking chiropractic care produced no extra risk for stroke over and above the background rate.  It appears that patients about to have a stroke from a dissection of a vertebral artery (the kind blamed on chiropractic for 80 years) seem to go to a doctor (a medical doctor or a chiropractic doctor) and the only reason the association between chiropractic and stroke appeared to be strong and not for PCPs is that no one asks the question in the emergency room, "did you see your MD within the past month?"

Some have complained that Cassidy et al was a "statistical study" (see this opinion piece or listen to Dr. Murray Katz's testimony before the Connecticut Board of Chiropractic Examiners)  That's almost comical as a critique if not that it might ring true to people who don't understand biomedical research.  Those same critics never said that Rothwell (9) and Lee (10) were "statistical studies" which they are. 

In the publication BottomLine Health there is an article about stroke risk.  The author Dr. Steven Messe essentially dismisses cervical manipulation as a risk factor based upon Cassidy et al's work.(12) 

The nature of science is that what was known one day may change the next.  This isn't often comfortable to the average person but it is the way it is.As the late Prof. Natalia Romalis-Reytblatt (she was a math professor at UB and UB’s 2006-07 Professor of the Year) wrote:

Mathematical results are either false or true (that is, proven or false) and nothing in between. Mathematics is one of the oldest fields of study and, probably, the only field whose findings are not reversed over time, only accumulated.
Math doesn't reverse it's findings but biomedical science does.  A few years ago I wrote about the risk of stroke from cervical manipulation.  But then the evidence changed.  So in the end this is an argument about looking at the science or ignoring the science and using emotion or choosing to use old science only.  To hear the science you can listen to Dr. David Cassidy testify before the board.  You can decide. 

  1. Goldstein LB, Adams R, Alberts MJ, Appel LJ, Brass LM, Bushnell CD, et al. Primary prevention of ischemic stroke: a guideline from the American Heart Association/American Stroke Association Stroke Council: cosponsored by the Atherosclerotic Peripheral Vascular Disease Interdisciplinary Working Group; Cardiovascular Nursing Council; Clinical Cardiology Council; Nutrition, Physical Activity, and Metabolism Council; and the Quality of Care and Outcomes Research Interdisciplinary Working Group: the American Academy of Neurology affirms the value of this guideline. Stroke. 2006 Jun;37(6):1583-633.  (this paper is available for free here)
  2. Busse JW, Jacobs C, Ngo T, Rodine R, Torrance D, Jim J, et al. Attitudes toward chiropractic: a survey of North American orthopedic surgeons. Spine (Phila Pa 1976). 2009 Dec 1;34(25):2818-25. (Pubmed link)
  3. Getzendanner S. Permanent injunction order against AMA. Jama. 1988;259(1):81-2. (Pubmed link)
  4. Gabbay J, le May A. Evidence based guidelines or collectively constructed "mindlines?" Ethnographic study of knowledge management in primary care. Bmj. 2004 Oct 30;329(7473):1013.(this paper is available for free here)
  5. Schievink WI. Spontaneous dissection of the carotid and vertebral arteries. N Engl J Med. 2001 Mar 22;344(12):898-906. (Pubmed link)
  6. Lee KP, Carlini WG, McCormick GF, Albers GW. Neurologic complications following chiropractic manipulation: a survey of California neurologists. Neurology. 1995;45(6):1213-5. (Pubmed link)
  7. Haldeman S, Carey P, Townsend M, Papadopoulos C. Clinical perceptions of the risk of vertebral artery dissection after cervical manipulation: the effect of referral bias. Spine J. 2002 Sep-Oct;2(5):334-42. (Pubmed link)
  8. Haldeman S, Carey P, Townsend M, Papadopoulos C. Arterial dissections following cervical manipulation: the chiropractic experience. CMAJ. 2001 Oct 2;165(7):905-6. (this paper is available for free here)
  9. Rothwell DM, Bondy SJ, Williams JI. Chiropractic manipulation and stroke: a population-based case-control study. Stroke. 2001;32(5):1054-60. (this paper is available for free here)
  10. Smith WS, Johnston SC, Skalabrin EJ, Weaver M, Azari P, Albers GW, et al. Spinal manipulative therapy is an independent risk factor for vertebral artery dissection. Neurology. 2003 May 13;60(9):1424-8. (Pubmed link)
  11. Cassidy JD, Boyle E, Cote P, He Y, Hogg-Johnson S, Silver FL, et al. Risk of vertebrobasilar stroke and chiropractic care: results of a population-based case-control and case-crossover study. Spine. 2008 Feb 15;33(4 Suppl):S176-83. (Pubmed link)
  12. Messe SR. Stroke Risk. BottomLine Health. 2010;24(3):1-2. 

Sunday, March 28, 2010

Decompression - Yeah right

Spine and DiscImage by planetc1 via Flickr

Marketplace, a Canadian Broadcasting Corp (CBC) investigative TV show did a piece on decompression for low back pain.  This news item might get a lot of people angry.  I figure those who get mad will mostly be those who own and market the "decompression" machines.  Some of my chiropractic colleagues might get mad because they might believe that the chiropractic profession is put in a bad light but really I don't think so.  There was no inference that the problem with decompression machines is a chiropractic problem, the news piece just looked at one chiropractor's offices.  In fact they note that the College of Chiropractors of Ontario (the regulatory board for chiropractors in ONT) after being notified by Marketplace, will be investigating the chiropractor in the news piece regarding his advertisements.

So what are these non-surgical decompression machines?  Well they are just low back traction devices that cost a lot of money, thus require lots of patients to make the expenditure worth the money for the doctor.  Big bills means big advertising.  It is not uncommon for one to see very large advertisements in local newspapers.  These ads often have lots of claims of great success rates.  There are also claims that these are NASA technology.  Well those claims don't hold water as Marketplace found.  In fact the Oregon Attorney General's office has ruled that neither of these claims are valid and can't be used in Oregon.  I guess it's too bad if you live elsewhere.  I live in Connecticut and regularly see these ads in my local paper.

The real problem here is that people suffering with back pain are vulnerable to believing the advertisements because they are desperate to get relief.  The ads make it sound so good.  Go to the office, get an exam (may be just a wallet exam) and then get relief from this device with NASA technology and an 86% success rate.  Seems too good to be true, and of course it is.

Are there people with low back pain for whom traction is helpful?  The answer is yes but it shouldn't take thousands of dollars and months of care.  Research (1, 2) is starting to identify those people for whom traction is the best option but a definitive answer hasn't bee found yet.

So what is a poor suffering person to do?  Well one needs to find the doctor who isn't quick ordering any treatment or isn't really a one trick pony.  That means one that doesn't do traction on everyone.  Or doesn't do spinal manipulation on every patient.  Or doesn't schedule surgery - first thing. Or doesn't say exercise is a must for everyone.  Really treatment needs to be individualized to the patient.  One method for doing that is to use what my colleague Dr. Donald Murphy of the Rhode Island Spine Center has published as the diagnosis-based clinical decision rule.(3, 4)  There is more research that needs to be conducted on this method but I think it's the best model for how to manage the patient with spinal pain and determine the appropriate treatment.


1.    Fritz JM, Lindsay W, Matheson JW, Brennan GP, Hunter SJ, Moffit SD, et al. Is there a subgroup of patients with low back pain likely to benefit from mechanical traction? Results of a randomized clinical trial and subgrouping analysis. Spine. 2007 Dec 15;32(26):E793-800.
2.    Raney NH, Petersen EJ, Smith TA, Cowan JE, Rendeiro DG, Deyle GD, et al. Development of a clinical prediction rule to identify patients with neck pain likely to benefit from cervical traction and exercise. Eur Spine J. 2009 Mar;18(3):382-91.
3.    Murphy DR, Hurwitz EL. A theoretical model for the development of a diagnosis-based clinical decision rule for the management of patients with spinal pain. BMC Musculoskelet Disord. 2007;8:75.
4.    Murphy DR, Hurwitz EL, Nelson CF. A diagnosis-based clinical decision rule for spinal pain part 2: review of the literature. Chiropr Osteopat. 2008;16:7.

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Friday, February 5, 2010

Zero Tolerance - Sex With Patients

MILAN, ITALY - SEPTEMBER 26:  Italian designer...Image by Getty Images via Daylife

The College of Chiropractors of Ontario (the equivocate of a state board of chiropractic examiners) suspended the license of a chiropractor for 5 years for professional misconduct.  The doctor in question, treated his girl friend and then marked her bills paid.  She submitted them to insurance and would give him the funds.  After they broke up he tried to collect the balance of her account and then referred her account to a collection agency.  She didn't complain about his having had a sexual relationship with her, she complained about his billing practices.  Nevertheless there is a zero tolerance policy for having sex with patients and the College
The college's decision was based upon one salient fact, the doctor was having sex with a patient.  The nature of their relationship was immaterial. 
The issue which I've stressed in my classes on ethics and risk management as well as my ethics column that any relationship founded upon an imbalance of power is not consensual.  In the doctor-patient relationship the doctor has the professional knowledge and knowledge is power.  Thus there is a professional boundary between the patient and the doctor that can never go beyond that relationship.
For more details see the article in the Globe and Mail:  Giving care to his girlfriend puts chiropractor in hot water or on CTV Waterloo chiropractor loses his license
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Wednesday, February 3, 2010

Foot Detox Pads

rancidImage by welovepandas via Flickr

Laura Johannes writes in the WSJ online about the silliness called foot detox pads.  Congratulations for getting to the bottom of this pile of crap.  The sale of these pads and the use of ion detox foot baths are proof positive that science hasn't really affected the thinking of enough Americans to prevent snake oil salesman from making a living in our modern age. 

The great irony of today's internet, driven by content sensitive advertising is that the "sponsored links" just below her article are for three companies that sell the items she has just attempted to debunk.  Gotta love adsense or is it nonsense.

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Tuesday, February 2, 2010

Autism's False Profit - Disciplined

LONDON, ENGLAND - JANUARY 28:  Dr Andrew Wakef...Image by Getty Images via Daylife

Andrew Wakefield is the medical doctor whose discredited research started the whole scare over MMR causing autism has been disciplined by the General Medical Council (GMC) in the UK.  The GMC (the regulatory agency that oversees the medical profession in the UK) ruled that Wakefield had showed a “callous disregard” for the suffering of children.  They also ruled that his research was deceptive. 

Wakefield and colleagues published a paper in the prestigious and venerable British medical journal, The Lancet which detailed 8 children who supposedly became autistic after getting the MMR vaccine.  The children had gastrointestinal symptoms which lead to the theory that the vaccine changed the permiablity of the GI track and allowed substances into the blood and eventually to the brain resulting in autism.  The paper said that the children were consecutively seen when this was not true.  Most of the authors retracted the paper 6 years after it was published and today the journal completely retracted the 1998 paper that created all the controversy.  What allowed the journal to retract the paper was the GMC's decision that the paper was deceptive. 

I guess one could say too little too late.  On the other hand I view this as the self correcting nature of science.  Clearly there has been significant harm because of this paper and the hysteria it has provoked.  Those who believe that vaccines are the cause of autism, of course, will not let any amount of scientific evidence change their minds.  As it is said “You cannot reason people out of a position they have not reasoned themselves into.”


NY Times article about this

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