The random thoughts of a sceptical activist

The GCC’s Plethora

Well. The GCC’s ‘independent’ review of the effectiveness of chiropractic has finally been published: Effectiveness of manual therapies: the UK evidence report (although not yet on the GCC’s website).

Paid for by the GCC (see page 77), this document runs to 113 pages and there is additional commentary by two others, adding a further 13 pages.

It’ll take time to read through and digest fully, but here’s a handy summary of what they did — and didn’t — find evidence for. They have listed conditions in three categories: effective, inconclusive and ineffective.

Spinal manipulation/mobilization is effective in adults for:

  • acute, subacute, and chronic low back pain;
  • migraine and cervicogenic headache;
  • cervicogenic dizziness;
  • a number of upper and lower extremity joint conditions.

Thoracic spinal manipulation/mobilization is effective for:

  • acute/subacute neck pain.

When combined with exercise, cervical spinal/manipulation is effective for:

  • acute whiplash associated disorders;
  • chronic neck pain.

The evidence is inconclusive for cervical manipulation/mobilization alone for:

  • neck pain of any duration.

The evidence is inconclusive for any type of manipulation/mobilization for:

  • mid back pain;
  • sciatica;
  • tension-type headache;
  • coccydynia;
  • temporomandibular joint disorders;
  • fibromyalgia;
  • premenstrual syndrome;
  • pneumonia in older adults.

Spinal manipulation is not effective for (compared to sham manipulation):

  • asthma;
  • dysmenorrhea;
  • stage 1 hypertension when added to an antihypertensive diet.

For children, the evidence is inconclusive regarding the effectiveness of spinal manipulation/mobilization for:

  • otitis media (ear infections);
  • enuresis (bed wetting).

but shows it is not effective for:

  • infantile colic;
  • improving lung function in asthma when compared to sham manipulation.

They also considered the evidence for massage.

The evidence regarding massage shows that for adults it is an effective treatment option for:

  • chronic lower back pain;
  • chronic neck pain.

The evidence is inconclusive for:

  • knee osteoarthritis;
  • fibromyalgia;
  • myofascial pain syndrome;
  • migraine headache;
  • premenstrual syndrome.

For children, the evidence is inconclusive for:

  • asthma;
  • infantile colic.

Of course, a lot hangs on what they mean by ‘effective’, ‘ineffective’ and ‘inconclusive’, what they included and excluded from their scope and how they came to their conclusions. It will also be interesting to see if anything differs from the independent Cochrane reviews.

No doubt this will be dissected very carefully over the coming days, but at face value, it is a damning indictment of a vast number of claims chiropractors have been making.

19 Responses to The GCC’s Plethora

  • I skimmed the report very quickly. Superficially it gives the impression that they critically examined the evidence.

    However, I looked for, but did not see, that they had considered the risk of bias in open (unblinded) studies that compared chiropractic with usual care/best usual care. These sorts of studies are often called pragmatic trials.

    The best evidence for chiropractic for persistent low back pain (and I suspect for most other conditions) comes from open pragmatic trials. Advocates of chiropractic assume that if the patients are randomized to treatments, and if the trial is otherwise well performed, the lack of blinding does not pose a risk that the results could be biased. I have searched the literature fairly diligently and can find no evidence that this complacency is justified.

    There are two sources of bias that plausibly could arise from people disgruntled by being assigned to the usual care group, and one source of bias plausibly arising from people being pleased that they have been assigned to receive chiropractic.

    Usually people will have already “failed” to respond to usual care, are looking for anything that might help them, and have heard that chiropractic is effective. They will be expecting to be helped by chiropractic, and to be not helped by usual care.

    The group assigned to usual care could show a negative placebo effect. And, they could express negative cognitive measurement biases by exaggerating their scores in self-reported pain and disability scales. These negative biases will increase the difference between the chirpractic and control group, and they will appear to be benefits for chiropractic, when they are anything but.

    The group assigned to chiropractic could plausibly experience a positive placebo effect, which is to be welcomed. They could also plausibly express a positive cognitive measurement bias by exagerating the improvement they record in self-reproted pain and disability scales. This would look like a placebo effect and a benefit for chiropractic, but kidding yourself is not something that should be encouraged.

    The point I am making is that the best evidence for chiropractic for low back pain (and probably for other conditions) is based on results that are probably biased towards chiroractic. The evidence thus provides much weaker support for chiropractic than is generally supposed.

    There is exactly the same problem with the evidence supposed to support acupuncture.

    It would be great if you (and/or bloggers) could carefully check the GCC’s ‘independent’ review of the effectiveness of chiropractic and document if they have taken account of these sources of bias.

  • Hmm. Excellent. But the question is whether this shows there is more or less than a “jot”….

  • Michael said: “There is exactly the same problem with the evidence supposed to support acupuncture.”

    There is now a pretty good sham acupuncture procedure and clinical trials using this procedure show that acupuncture is useless.

  • @BillyJoe said “There is now a pretty good sham acupuncture procedure and clinical trials using this procedure show that acupuncture is useless.”

    The few trials that have compared chiropractic with a sham procedure have also found no clinically important difference.

    Proponents of CAM shrug this off, and say that it doesn’t matter because what is important is the “package of care”. What they don’t notice is that the *measured* effects of the package of care reflect the difference between:

    positive placebo effects plus positive cognitive bias effects in the treatment group,

    and

    negative placebo effects plus negative cognitive bias effects in the comparison group.

    If the positive placebo effects are clinically important, they are likely to be swamped by all the biases.

  • I just read the commentary, and I suggest that those reading the report take note of citations to manipulation performed by non-chiropractors. It is a common chiro ploy to take credit for the work of others (while proclaiming the superiority of their own work).

  • This is my last comment on this particular blog!

    Gert Bronfort, the first author of the report, introduced me to interpretation bias with his paper “Efficacy of spinal manipulation and mobilization for low back pain and neck pain: a systematic review and best evidence synthesis”.

    What he meant by “best evidence synthesis” was to count all the positive results (while ignoring the negative results) in his systematic review, which put heavy emphasis on how the quality of included papers was assessed. Basically he assessed a quality score, but took no account of risks of bias.

    You can find Bronfort’s “best evidence synthesis” here:
    http://www.ncbi.nlm.nih.gov/pubmed/15125860?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=3

    Neil E. O’Connell and Ben Goldacre have a good paper on interpretive bias in acupuncture here:

    http://ehp.sagepub.com/cgi/content/abstract/32/4/393

  • So it seems that chiroquactic is only marginally more effective than homeopathy and voodoo.

  • Zeno posts: >>”….there is additional commentary by the authors, adding a further 13 pages.”<<

    This is inaccurate and misleading. The authors of the paper are NOT the authors of the commentary.

    The PAPER can be found HERE: http://www.ncbi.nlm.nih.gov/pubmed/20184717?dopt=Abstract&holding=f1000,f1000m,isrctn

    AND HERE: http://www.chiroandosteo.com/content/pdf/1746-1340-18-3.pdf

    THE COMMENTARY – ("This is an accompanying commentary on the article by Gert Bronfort and colleagues about the effectiveness of manual therapy. The two commentaries were provided independently and combined into this single article by the journal editors.")

    Can be found HERE: http://www.chiroandosteo.com/content/pdf/1746-1340-18-4.pdf

    AND HERE: http://www.ncbi.nlm.nih.gov/pubmed/20184721?dopt=Abstract&holding=f1000,f1000m,isrctn

    I trust you(and all in your web ring) will, in appreciation of the importance of accuracy, edit and correct promptly.

  • nene

    Thanks for pointing out my error, which I am happy to correct. However, I’m sure you understand how I made that error:

    This is an accompanying commentary on the article by Gert Bronfort and colleagues about the effectiveness of manual therapy. The two commentaries were provided independently and combined into this single article by the journal editors.

    It is not entirely clear that “by Gert Bronfort and colleagues” was referring to the article and not the commentary.

    I’m not sure why you repeated the links I have already given, but thanks for giving the links to the documents on the nih.gov website.

  • You people are asses. It wouldn’t matter what that report said, you’d still criticize it.
    You’re fine scientific fundamentalists. By the way I hope you read the bit about Edzard Blimpy Ernst’s errors.
    Do read the whole thing and then continue to tell all your pussy blogger army that it’s rubbish.
    Your beloved savior Singh (with bad hairdo) said chiropractors aren’t effective for anything–even for low back pain.
    And make sure that you call me a quack to my face the next time I visit your fair country .

  • @Robin

    “And make sure that you call me a quack to my face the next time I visit your fair country .”

    Why – what are ya gonna do, Robin? Punch him in the face?

    I can see your brains ran out before you even hit the keyboard so thinly veiled threats don’t surprise me at all.

    Twat.

  • @skepticat

    maybe.

    Thanks for the mild insult. I would have expected someone like you to use a more
    effeminate word like tat,kak,piffle or pants.

  • It never fails to amaze me when someone trying to defend chiropractic or any alternative medicine does so by making inane childish insults. Calling Edzard ‘blimpy’ and saying that Simon has a bad haircut does not make up for the glaring lack of evidence for many chiropractic claims. What it does do, especially when coupled with idiotic internet threats, is create the impression that those defending chiropractic are incapable of having a mature discussion and can only respond with tactics better suited to the playground than a scientific debate.

    Good job all round Robin!

  • Well said, Chris.

    The ad hominems seem to be a particular favourite of those who know they’ve already lost the argument.

  • Chris and Joe,
    What you’re saying is exactly what you do yourselves. You’ve got all these blogs around tearing
    chiropractic to shreds having a good laugh. Twat is a childish insult,right.
    You skeptics asked for evidence. It was given.You just don’t like it. You’ve picked apart everything.
    You look for one study that bolsters your position and ignore others that you don’t like.
    The majority of your sites are full of people patting each other on the backs,laughing about how
    silly chiropractors, chiroquackters and whatever other names you intelligent-types use to insult us.
    There have been no mature discussion on any of these blogs just a lesson in who argues best.

  • Robin

    You may have forgotten that you started your first comment on here with:

    You people are asses.

    Not an auspicious start for someone decrying the level of argument.

    However, if anyone is ‘tearing chiropractic to shreds’, then it is because it is capable of being torn to shreads.

    If you care to read through the Bronfort report (regardless of how flawed it is), you will see that it’s the chiros who have been doing the cherry picking. It’s just a pity it has taken so long for chiros to even start to grasp the nettle that is the paucity of evidence for what they claim.

    If you want to have a mature discussion about the evidence for chiropractic, please feel free to join in but please provide robust evidence to back up your arguments. And without the ad hominems. Please refer to the Comment Guide, particularly number 6.

    To get you started, you said (with ad hominems removed):

    …Singh…said chiropractors aren’t effective for anything–even for low back pain.

    Can you point me to where he said this?

  • The problem with this is that Robin may well be an 8 year old in china but you presume ” when someone trying to defend chiropractic or any alternative medicine does so by making inane childish insults.” He may be a child, he may not know or have anything to do with chiropractic so maybe you should view his comments for what they are, ranting.

  • Hi all, I watch with interest the debate that appears to be raging within the blogsphere. I, as a Chiropractor appreciate the efforts made to eradicate a section of the profession, or at the very least get them to reign in their claims.
    I am bewildered with the evident hair splitting, minute analysis and the amount of time some people must be spending pursuing this subject. I am also curious that only Chiropractic and Homeopathy could be the only professions that could be so flawed.

  • They’re not.

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