Spinal manipulative therapy for chronic low-back pain: an update of a Cochrane review. Rubinstein SM, van Middelkoop M, Assendelft WJ, de Boer MR, van Tulder MW. Spine (Phila Pa 1976). 2011 Jun;36(13)
Systematic review of interventions.
To assess the effects of spinal manipulative therapy (SMT) for chronic low-back pain.
SUMMARY OF BACKGROUND DATA:
SMT is one of the many therapies for the treatment of low-back pain, which is a worldwide, extensively practiced intervention.
Search methods. An experienced librarian searched for randomized controlled trials (RCTs) in multiple databases up to June 2009. Selection criteria. RCTs that examined manipulation or mobilization in adults with chronic low-back pain were included. The primary outcomes were pain, functional status, and perceived recovery. Secondary outcomes were return-to-work and quality of life. Data collection and analysis. Two authors independently conducted the study selection, risk of bias assessment, and data extraction. GRADE was used to assess the quality of the evidence.
We included 26 RCTs (total participants = 6070), 9 of which had a low risk of bias. Approximately two-thirds of the included studies (N = 18) were not evaluated in the previous review. There is a high-quality evidence that SMT has a small, significant, but not clinically relevant, short-term effect on pain relief (mean difference -4.16, 95% confidence interval -6.97 to -1.36) and functional status (standardized mean difference -0.22, 95% confidence interval -0.36 to -0.07) in comparison with other interventions. There is varying quality of evidence that SMT has a significant short-term effect on pain relief and functional status when added to another intervention. There is a very low-quality evidence that SMT is not more effective than inert interventions or sham SMT for short-term pain relief or functional status. Data were particularly sparse for recovery, return-to-work, quality of life, and costs of care. No serious complications were observed with SMT.
High-quality evidence suggests that there is no clinically relevant difference between SMT and other interventions for reducing pain and improving function in patients with chronic low-back pain. Determining cost-effectiveness of care has high priority. [emphasis mine]
A couple additional quotes from the paper:
One objection typically raised by clinicians is the lack of respect to the type of manipulative therapy delivered (e.g. high-velocity low-amplitude manipulation versus mobilization) or profession of the therapist (e.g. chiropractor versus manual therapist or physiotherapist). Sensitivity analyses were conducted in order to distinguish whether this resulted in a different effect; however, those results suggest that neither the technique nor profession of the therapist had a profound influence on the overall pooled effect.
Surprisingly, many of the studies published in the last decade did not have a published protocol and to our knowledge, had not registered their study in one of the many trial registries, indicating that many trials conducted in the 21st century still do not conform to international procedure. In the absence of 100% conformity, it remains difficult to ascertain to what extent studies do not publish their findings because the results prove less than favourable.
My comments regarding this Cochrane review could be almost identical to that of my earlier blog regarding manipulative therapy for acute low back pain however this one looked at people with back pain with lasting longer than 12 weeks. The authors are the same and the results are pretty much the same. So I would encourage reading the former and I’ll try to make this one a little different.
I would reword the above abstract to say there is a lot of research done already, ⅔ of the research has a high risk of bias (bias in medicine is generally in favor of a positive result) and even so there is no indication that the treatment works better than placebo. The primary author (who is a chiropractor who uses manipulation as part of his daily practice) admits as much, so I question his suggestion for further research regarding a cost benefit analysis.
The paper does indicate that manipulation/mobilization has been shown to work as well as other conventional treatments. However I don’t think the latter should be much of a surprise since a good number of studies indicate that a good number of conventional treatments don’t work either. The parallel I would draw would be with McKenzie Method (arguably a conventional treatment) for the treatment of low back pain, where it compares favorably to Williams flexion exercises (another conventional treatment) but was found to be no better than advice to stay active. The reason likely being that spine flexion stretches (which is what Williams Flexion exercises always are and McKenzie stretches occasionally are) is the stress that causes disc bulges, herniations and degeneration.
The researchers reported several forms of bias potentially present in the research. Only 3/26 papers attempted to blind the subjects with a sham treatment. None of them attempted to blind the administers of the treatment, which unfortunately is impossible. Only half of the studies provided an overview of subject drop outs. Published/registered protocols were available for only 5/26 papers allowing the opportunity for selective reporting and publication bias. Given the small effects, I would be surprised if the various biases didn’t explain every bit of the admittedly small benefits.
As for more time and money being put into researching a cost-benefit analysis, that just seems like time and money wasted. If potentially biased research shows no effect or (at best) effects so minimal as to be of no practical significance, my conclusion would be to stop wasting healthcare dollars on it and certainly stop wasting valuable research dollars on it. Otherwise one of my favorite Nietzsche quotes seems apt:
“…they spend their day sitting at swamps with fishing rods, thinking themselves profound: but whoever fishes where there are no fish, I would not even call superficial.”
Rather I would suggest that such dollars for the treatment and prevention of low back pain and disability be better spent optimizing exercise programs, ergonomics, motor control, etc. preventing back pain stresses, which are no secret, and for which vertebral mobilization and manipulation is powerless to affect.
As always, if by the end of my blog you find yourself having any further questions or need for clarifications, please don’t hesitate to ask. Being aware that some of my blog ideas are contentious and occasionally a bit out of the field of my expertise, I encourage my readers to come forth with any questions/comments that are of interest or concern. Your comments are valued and welcomed.
Chad Reilly is a licensed physical therapist, located in North Phoenix, practicing science based medicine with treatment protocols unique and effective enough to proudly serve patients from Phoenix, Scottsdale, Mesa, Chandler, Tempe, Peoria, and Glendale.