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Profession Responds Quickly to Negative U.K. Study on Spinal Manipulation

Editorial Staff

A controversial review paper published in the April 2006 issue of the Journal of the Royal Society of Medicine (JRSM) has caused quite a stir among the chiropractic profession, and for good reason: The study authors, E. Ernst and P.H. Canter, conclude that there is "no convincing evidence from systematic reviews to suggest that [spinal manipulation] is a recommendable treatment option for any medical condition."

The Foundation for Chiropractic Education and Research (FCER) and the American Chiropractic Association (ACA) are among the chiropractic organizations that have issued formal responses to the Ernst/Canter paper; we have reproduced those responses in their entirety. As of press time, a free full-text version of the study is available on the JRSM Web site at www.jrsm.org/cgi/content/full/99/4/192.

The FCER Response

NORWALK, Iowa - In the April 1, 2006 issue of the Journal of the Royal Society of Medicine, Ernst and Canter summarized 16 systematic reviews published between 2000 and May 2005 on the effectiveness of spinal manipulation. The Foundation for Chiropractic Education and Research (FCER) is always open to results of research if the research proves to be of good quality and lacking bias. The biases in this study are painfully apparent, rendering the sweepingly negative "findings" little more than the authors' personal opinions.

Ernst and Canter concluded that these data do not demonstrate that spinal manipulation is an effective intervention for any condition.

According to them, the data fail to demonstrate that spinal manipulation is effective for treating back pain, neck pain, dysmenorrhea, infantile colic, asthma, allergy, cervicogenic dizziness, and any medical complaint. The exception was for back pain, where spinal manipulation may be superior to sham manipulation but not to conventional interventions. Considering the possibility of adverse events associated with spinal manipulation, the authors determined that their review "does not suggest that spinal manipulation is a recommendable treatment."

This study is so far from what would be considered a methodical and robust systematic review without bias as to render it highly suspect, if not meaningless. Its methods of analyses have not been validated, but rather reveal the authors' own carelessness - if not outright distortion - of the literature which it cites. Many of its glaring defects are ones that the authors attempt to criticize in other work. It fails to grasp how the hypotheses and methods of analysis in the reviews that it cites are bound to deliver differing conclusions, such that Ernst and Canter go out of their way to criticize the positive findings of a single chiropractic author, while overlooking their own consistently negative findings for chiropractic, which appear in no less than 25% of the reviews that they include in their discussion. Finally, the authors fail to recognize the major flaws in several of the primary sources of data which comprise the systematic reviews under scrutiny in this research.

There are issues surrounding the Ernst and Canter review that substantially undercut any prompt and uncritical acceptance of its conclusions. These include (1) the failure of systematic reviews and meta-analyses to consider subgroups of patients receiving treatment; (2) the design flaws of a large number of the randomized controlled trials which comprised the systematic reviews addressed in this report; (3) the failure to consider that modern evidence-based medicine is based upon clinical observation as well as randomized clinical trials; (4) the failure to adequately address the relative risks of other treatments available in conventional medicine for the conditions discussed in this review; and (5) numerous revelations of bias of one of the authors (Ernst) which have been amply demonstrated and refuted elsewhere. Under these circumstances, Ernst and Canter's study can be greeted only with the most extreme skepticism.

In lacking many of the elements required for a meaningful presentation of the evidence required for supporting treatment alternatives, this current report should not be considered worthy of guiding a clinical decision. As such, the glaring weaknesses of the report only serve to undermine the public's confidence in science as a means to inform health policy.

The ACA Response

Editor's note: ACA President Richard Brassard, DC, submitted the following to the editor of the Journal of the Royal Society of Medicine on March 23, 2006.

Dear Editor:

I'm deeply concerned about your recent news report stating that spinal manipulation offers no benefits for chiropractic patients. Your report stems from a systematic review co-authored by Professor Edward Ernst and Peter Canter that can be found in the April 2006 issue of the Journal of the Royal Society of Medicine. It is important for readers to know that the study cited in your report is biased and misleading - and disregards a plethora of research supporting the efficacy and safety of spinal manipulation.

The truth be told, the authors have limited the evidence to suit their own arguments, and in fact, they have included so much of their own opinionated research - approximately one-fifth of the papers cited - that their study is closer to personal opinion than an unbiased review. The authors have not included all research on the topic and have selectively chosen trials that support their preconceived ideas.

Numerous studies have established that manipulation and other forms of manual therapies are safe and highly effective forms of treatment. The research - when looked at in its entirety and in an independent and unbiased manner - shows that spinal manipulation for neck pain, back pain and headaches is effective. And in certain cases such as otitis media and asthma, spinal manipulation may be effective, but more research is needed in these areas to determine how effective it is.

A significant amount of evidence has shown that the use of chiropractic care for acute and chronic lower-back pain can be more effective and less costly than traditional medical care. A March 2004 study in the Journal of Manipulative and Physiological Therapeutics found that chiropractic care is more effective than medical care at treating chronic low-back pain in patients' first year of symptoms. In addition, a study published in the July 15, 2003 edition of the medical journal Spine found that manual manipulation provides better short-term relief of chronic spinal pain than do a variety of medications.

Moreover, in a report released by the Duke University Evidence-Based Practice Center in Durham, N.C., researchers found that spinal manipulation may be an effective treatment option for tension headaches and headaches that originate in the neck. Based on an extensive literature review of several headache treatment options, the panel of 25 multidisciplinary experts concluded that spinal manipulation resulted in almost immediate improvement for cervicogenic headaches and had significantly fewer side effects and longer-lasting relief than amitriptyline, a commonly-prescribed medication. In addition to being an extremely effective form of care, chiropractic is also one of the safest types of treatment available today - contrary to what was published in your report.

The American Chiropractic Association believes that patients have the right to know about the health risks associated with any type of treatment, including chiropractic. The most common adverse reaction that patients experience after spinal manipulation is minor discomfort, which - according to the scientific literature - usually fades within 24 hours. Beyond that, recent scientific studies put the risk of a major complication of manipulation of the lower back region at 1 in 100 million manipulations.

Millions of people, including sports heroes such as Lance Armstrong and Tiger Woods, celebrities, professional athletic teams, and even medical doctors, seek chiropractic care every day, and are happy with the results. Based on scientific evidence and from my own clinical experiences, patients greatly benefit from spinal manipulation.

Unfortunately, the conclusion of this paper was preconceived before the authors began writing. If we look at the co-authors' previous works, they have been highly critical not just of spinal manipulation, but also of any other complementary or alternative medicine.

Please consider this information as you advise your readers about their health care options. I hope that you will consider the American Chiropractic Association (www.acatoday.org) as a resource for future news reports.

Richard G. Brassard, DC, ACA President

May 2006
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