Jul 08 2009
Simon Singh is a science journalist who last year wrote an article in the Guardian critical of the British Chiropractic Association (BCA) for promoting chiropractic treatment for certain childhood ailments. Singh characterized these treatments as “bogus” because they lack evidence to back up claims for clinical efficacy. The BCA responded by suing Singh for libel. In the English court system the person being sued for libel is essentially guilty until proven innocent, and even successfully defending oneself can be ruinously expensive. Therefore suing for libel in English court is a very successful strategy for silencing critics.
This case resulted in a bit of a backlash against the BCA, who were accused of silencing legitimate and very necessary public scientific debate regarding the safety and efficacy of medical interventions. The BCA could have simply responded by providing evidence to back up their claims, and the Guardian even offered them space to do so, but instead they sued.
Part of this backlash is a movement, supported by many scientific organizations, to keep libel laws out of science.
Recently the BCA has responded to this backlash with a statement and a list of studies they claim provides the evidence Singh said was lacking. I won’t address their attempt at damage control, but rather focus on their response regarding the evidence. They write:
In the spirit of wider scientific debate, and having taken appropriate professional advice, the BCA has decided that free speech would be best facilitated by releasing details of research that exists to support the claims which Dr. Singh stated were bogus. This proves that far from being “not a jot of evidence” to support the BCA’s position, there is actually a significant amount.
They follow their statement with a list of 29 studies. This is a short reference list to support several individual medical claims, but actually it is a bloated list that contains many references that do not provide evidence for the claims of the BCA that Sign was criticizing. This is how the 29 references break down:
3 – Risks of NSAID medication
1 – Nature of evidence-based medicine
3 – opinion, chiropractic practice
1 – letter to editor
2 – review
2 – risks of chiropractic
8 – colic
3 – nocturnal enuresis
3 – otitis media
3 – asthma
Therefore, out of the 29 references, only 17 actually provide evidence for the efficacy claims for chiropractic for these four pediatric indications. When each indication is considered, the list of supporting studies is embarrassingly thin. They are also of very poor quality and, as we will see, cherry picked.
It should also be noted that the notion of spinal manipulation for medical issues, like a middle ear infection, is highly implausible. Such implausible claims should require robust clinical evidence before putting them into practice. The evidence presented by the BCA is far from robust, and when the totality of evidence is considered it is actually negative.
Of the 8 studies presented for colic, one is a preliminary assessment of cranial osteopathy for colic. In the past chiropractors have complained that studies of non-chiropractic forms of manipulation cannot be used to dismiss the efficacy of chiropractic. It is disingenuous of the BCA to pad their list of evidence for chiropractic by including a study of osteopathic manipulation. Two of the studies were case reports. One report is a response to a questionnaire, and there were three unblinded or single-blinded studies, and one uncontrolled study. Therefore, not one prospective, double-blind, placebo-controlled study is presented. All we are given is low grade evidence.
Also, the BCA left off the best designed study, which not surprisingly was negative. Olafsdottir et al (1) studied 86 infants with colic in a randomized controlled trial and found:
“Chiropractic spinal manipulation is no more effective than placebo in the treatment of infantile colic.”
How does the BCA justify omitting this study from their list? Do they think that an open scientific discussion of evidence means presenting only the evidence that seems to support their position?
The BCA also neglected to reference a review of the evidence for chiropractic for colic by Hughes and Bolton (2) which concludes:
“The evidence suggests that chiropractic has no benefit over placebo in the treatment of infantile colic. However, there is good evidence that taking a colicky infant to a chiropractor will result in fewer reported hours of colic by the parents.”
Their conclusion was curious – chiropractic treatment for colic does not work but parents report that it does. Ordinarily science-based practitioners would simply interpret such results as being consistent with a placebo effect alone.
What we see is the typical pattern of evidence for an ineffective treatment – low grade evidence showing an effect, but higher grade controlled evidence showing no effect above placebo. The bottom line is that existing evidence suggests that chiropractic manipulation is not effective in the treatment of colic. But the BCA cherry picked only the low grade evidence that supported their claim.
Of the three asthma studies presented, two were of osteopathic manipulation and the third is a case series and pilot study. The two osteopathic studies were looking at markers of pulmonary function, and not clinical outcomes. Again, it is very telling that these three weak studies are all the BCA could come up with.
And again, the BCA left off their list the largest and most definitive study of chiropractic treatment for childhood asthma – the 1998 New England Journal of Medicine study (3). This was a large randomized controlled trial, which found:
In children with mild or moderate asthma, the addition of chiropractic spinal manipulation to usual medical care provided no benefit.
The pattern repeats again – the best data shows no effect from manipulation. It is my sincere contention that if the exact same evidence (even leaving out the lack of plausibility) existed for a medical treatment, it would be abandoned as a worthless dead end. At the very least, use would stop until further research were done. There might even be concerns about the ethics of further research given the negative evidence and lack of plausibility.
The BCA and chiropractors in general have simply ignored or dismissed the negative evidence of chiropractic for asthma and instead cherry pick the very low-grade evidence that seems to support what they want to claim. This makes chiropractic treatment for asthma “bogus.”
There is precious little research into the treatment of acute otitis media (middle ear infection) with chiropractic adjustment. The three studies cited are all retrospective or uncontrolled. There are no double-blind placebo controlled studies – and therefore no reliable evidence upon which to base a clinical claim.
Again, we have three weak studies and nothing to defend the implausible claim that chiropractic treats nocturnal enuresis. One of the studies cited is by Reed et al, which concludes:
“The mean pre- to post-treatment change in the wet night frequency for the treatment group compared with the control group did not reach statistical significance (p = 0.067).”
In other words – this is a negative study. The comparison of treatment to control showed no statistically significant difference. There was a trend – but they are not reliable enough to serve as a basis for clinical conclusions. That is the whole point of statistical significance. This was a small study, so you can say that it was simply not powerful enough to detect an effect – but that still leaves us without evidence to support the claim for an effect.
A Cochrane review of the evidence regarding chiropractic and other alternative treatments for nocturnal enuresis concluded:
“There was weak evidence to support the use of hypnosis, psychotherapy, acupuncture and chiropractic but it was provided in each case by single small trials, some of dubious methodological rigour.”
The BCA’s list of evidence for these four clinical claims is not impressive. The best they have to offer is a few weak and poorly designed studies. They also ignore larger better trials where available that are negative.
A more thorough assessment of the evidence for chiropractic treatment for asthma and colic reveals evidence for lack of efficacy. For otitis media and nocturnal enuresis there is a lack of evidence for efficacy.
Despite the state of the evidence, the BCA feels they are justified in promoting chiropractic for these pediatric indications. The reader can decide if the term “bogus” applies.
1) Olafsdottir E, Forshei S, Fluge G, Markestad T. Randomised controlled trial of infantile colic treated with chiropractic spinal manipulation. Arch Dis Child. 2001 Feb;84(2):138-41.
2) Hughes S, Bolton J. Is chiropractic an effective treatment in infantile colic? Arch Dis Child. 2002 May;86(5):382-4.
3) Balon J, Aker PD, Crowther ER, Danielson C, Cox PG, O’Shaughnessy D, Walker C, Goldsmith CH, Duku E, Sears MR. A comparison of active and simulated chiropractic manipulation as adjunctive treatment for childhood asthma. N Engl J Med. 1998 Oct 8;339(15):1013-20.
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