New Study Questions Effectiveness of SMT for LBP
By Simon French

A meta-analysis published in the Annals of Internal Medicine¹ in June has concluded that there is no evidence that spinal manipulative therapy (SMT) is superior to other standard treatments for patients with acute or chronic low back pain (LBP). This is in contrast to the Shekelle et al meta-analysis published over 10 years ago², that concluded “spinal manipulation is of short-term benefit in some patients, particularly those with uncomplicated, acute low back pain.” Why the change of heart in regards to SMT for LBP?

The study searched through the literature from 1966 to Jan 2000 to attempt to combine the data from all studies that have examined SMT in the treatment of LBP. Thirty-nine randomised controlled trials (RCTs) were identified and the data extracted to perform a meta-analysis. A meta-analysis is a statistical technique that attempts to pool the results from many different studies.

The studies identified compared SMT to other therapies believed to be effective including conventional general practitioner (GP) care, analgesics, physical therapy, exercises and back school. SMT was also compared to a collection of therapies judged to be ineffective or harmful including sham manipulation, traction, corset, bed rest, home care, topical gel, no treatment, diathermy and minimal massage.

The study found that SMT was consistently effective for patients with acute LBP when compared to the therapies that are believed to be ineffective or harmful. However, the study found that the evidence was inconsistent regarding the effect of manipulation compared to the other recommended treatments listed above.

The authors suggested their review shows SMT is unlikely to be effective for any group of patients with low back pain and subsequently that further research is not necessary unless they concentrate on cost-effectiveness. However, their review has identified the poor quality of many studies. Further studies should compare SMT to ‘proven’ therapies for both acute and chronic LBP. Further, the effectiveness of manipulation combined with other therapies – as is commonly performed in many chiropractic and osteopathic offices – in a range of spinal conditions is warranted.

A number of sensitivity analyses were also carried out, including comparing studies where the SMT was carried out by a chiropractor or not. The authors found no difference in effectiveness between these studies and others, ie whether a chiropractor performs the SMT or not, doesn’t effect the results.

How this review will be reported depends on the ‘spin’ put on the results. The review showed that SMT is superior to sham manipulation and to therapies judged to be ineffective or harmful. It did not, however, prove to be superior to the other effective therapies. In other words, SMT was better than placebo and as good as other effective therapies. In fact, the authors conclude that ‘spinal manipulative therapy is one of several options of only modest effectiveness for patients with low back pain’. The problem lies with individuals who will inevitably claim that SMT is not effective as a result of this review. It depends upon interpretation.

There is an ongoing debate regarding the validity of the meta-analysis. In this particular case, studies are combined with different types of LBP, different practitioners performing the SMT, different outcome measures and different comparison therapies. Whether a meta-analysis is a valid way to judge any therapy, let alone SMT, will no doubt be the subject of much future debate.

In light of this major new study and the current evidence based environment, chiropractors and osteopaths can no longer claim that SMT is ‘the’ recommended therapy for LBP. Researchers, along with practitioner support, are required to further evaluate the usefulness of SMT for LBP. Complacency will be our greatest enemy.

References:

1. Assendelft WJJ, Morton SC, Yu EI, Suttorp MJ, Shekelle PG. Spinal manipulative therapy for low back pain: A meta-analysis of effectiveness relative to other therapies. Annals of Internal Medicine 2003; 138:871-881.
2. Shekelle PG, Adams AH, Chassin MR, Hurwitz EL, Brook RH. Spinal manipulation for low-back pain. Annals of Internal Medicine 1992; 117:590-598.