Australasian Science: Australia's authority on science since 1938

Australian Chiropractors Manipulate the Evidence

By Ken Harvey

The Australian Health Practitioner Regulation Agency is dealing with more than 600 complaints about chiropractors. The majority of these cases involve caring practitioners who genuinely believe that their interventions are effective. The problem is their interpretation of evidence.

The Chiropractic Board of Australia, which supposedly regulates the professional conduct of chiropractors, has stated that high-level evidence is required to justify their advertising claims. The Board’s Code of Conduct includes the need to provide treatment or care options based on the best available information and to practise in an evidence-based context.

Despite these injunctions, many complaints about chiropractors note that the evidence used to justify their promotion and practice does not meet the Board’s requirements. The following examples, taken from real cases, are typical of many more.

Practitioner Experience
“I can categorically say that children under my care have experienced amazing changes with conditions such as colic, reflux, recurrent ear infections, learning difficulties and ADHD, to mention just a few.”

There are a number of reasons why practitioners and patients report that a treatment is effective when it’s not. These include the placebo effect (a patient’s expectation of an intervention), the natural history of disease (symptoms may wax and wane), confirmation bias (seeing what you expect to see), cognitive dissonance (ignoring results that don’t accord with expectations) and promotion by charismatic gurus.

In short, personal experience is easy, convincing and often wrong, while blinded, placebo-controlled clinical trials are laborious, complex and costly. However, the latter are crucial as they often show that initially promising results from observational studies are not replicated by well-conducted placebo-controlled trials.

The plural of anecdote is not evidence!

Lots of People Can’t Be Wrong
“Tens of thousands of babies and children all over the world every week visit chiropractors because chiropractic works.”

Unfortunately, popularity is not a reliable indicator of effectiveness. The history of medicine is littered with examples that demonstrate how misleading this fallacy can be. Bloodletting was highly popular, believed to be effective and practised for more than 3000 years yet it certainly killed more patients than it ever helped. Yet Semmelweiss’ revelation that, by washing their hands, doctors could avoid fatally infecting mothers in childbirth was resisted by his colleagues for years, and only became established practice only after he had died.

Selective Use of Low-level Studies
“Chiropractic care in pregnancy has been shown to significantly reduce the time a woman labours.”

This statement cites an old, poorly controlled and unreplicated case series reported by one chiropractic author. That does not justify its widespread use by chiropractors who cite the benefits of chiropractic in reducing the duration of labour.

Traumatic Birth (KiSS) Syndrome
“Even a smooth [normal] birth can be very traumatic on the baby’s neck.”

“Traumatic Birth Syndrome, whether it causes symptoms immediately or just diminishes human potential over the course of a lifetime, is a condition which should be addressed immediately after birth.”

The “KiSS Syndrome” is the creation of Dr Heiner Bierdermann. Others have noted that “there is no scientific evidence for the actual existence of ‘KiSS-syndrome’ as a clinical entity or for the positive effects of manual therapy”.

“Three-hundred-and-sixteen cases of colic were adjusted over a period of 2 weeks with a 94% success rate.”

This is an old uncontrolled study on a self-limiting condition. There was no placebo control group and no patient blinding. The authors were aware of methodological problems with the study and regarded it as inconclusive. Subsequent studies with parent blinding have not confirmed the value of chiropractic adjustment for colic.

In summary, the scientific literature used to justify chiropractic claims is often low-level testimonials, case reports, “expert” opinion, uncontrolled observational studies or cherry-picked studies that do not reflect the totality of the literature.

The Chiropractic Board has recently imposed conditions on the practice of one practitioner who used chiropractic adjustment on the spine of a 4-day-old baby for the management of colic and reflex. It’s hoped that this action might stimulate other chiropractors to make their promotion and management more evidence-based.

Ken Harvey is Adjunct Associate Professor in the School of Public Health at Monash University. This article is a brief summary of a major review prepared by Dr Harvey for the Chiropractor’s Association of Australia.