This systematic review assessed the effects and reliability of sham procedures in manual therapy (MT) trials in the treatment of back pain (BP) in order to provide methodological guidance for clinical trial development.
Different databases were screened up to 20 August 2020. Randomized controlled trials involving adults affected by BP (cervical and lumbar), acute or chronic, were included. Hand contact sham treatment (ST) was compared with different MT (physiotherapy, chiropractic, osteopathy, massage, kinesiology, and reflexology) and to no treatment. Primary outcomes were BP improvement, the success of blinding, and adverse effects (AE). Secondary outcomes were the number of drop-outs. Dichotomous outcomes were analyzed using risk ratio (RR), continuous using mean difference (MD), 95% CIs. The minimal clinically important difference was 30 mm changes in pain score.
A total of 24 trials were included involving 2019 participants. Most of the trials were of chiropractic manipulation. Very low evidence quality suggests clinically insignificant pain improvement in favor of MT compared with ST (MD 3.86, 95% CI 3.29 to 4.43) and no differences between ST and no treatment (MD -5.84, 95% CI -20.46 to 8.78).ST reliability shows a high percentage of correct detection by participants (ranged from 46.7% to 83.5%), spinal manipulation is the most recognized technique. Low quality of evidence suggests that AE and drop-out rates were similar between ST and MT (RR AE=0.84, 95% CI 0.55 to 1.28, RR drop-outs=0.98, 95% CI 0.77 to 1.25). A similar drop-out rate was reported for no treatment (RR=0.82, 95% 0.43 to 1.55).
The authors concluded that MT does not seem to have clinically relevant effect compared with ST. Similar effects were found with no treatment. The heterogeneousness of sham MT studies and the very low quality of evidence render uncertain these review findings. Future trials should develop reliable kinds of ST, similar to active treatment, to ensure participant blinding and to guarantee a proper sample size for the reliable detection of clinically meaningful treatment effects.
The optimal therapy for back pain does not exist or has not yet been identified; there are dozens of different approaches but none has been found to be truly and dramatically effective. Manual therapies like chiropractic and osteopathy are often used, and some data suggest that they are as good (or as bad) as most other options. This review confirms what we have discussed many times previously (e.g. here), namely that the small positive effect of MT, or specifically spinal manipulation, is largely due to placebo.
Considering this information, what is the best treatment for back pain sufferers? The answer seems obvious: it is a therapy that is as (in)effective as all the others but causes the least harm or expense. In other words, it is not chiropractic nor osteopathy but exercise.
avoid therapists who use spinal manipulation for back pain.