Table 2

Summary of findings of treatment effects and certainty of the evidence (GRADE) included for all comparisons

1. Sham treatment (ST) compared with manual therapies (MT)
Patient or population: back pain
Intervention: ST
Comparison: MT
Outcomes Anticipated absolute effects* (95% CI)Relative effect (95% CI)No of participants (studies)Certainty of the evidence (GRADE)Comments
Risk with MT Risk with ST
Pain improvement assessed with: VAS score§
Scale from: 0 to 100
MD 3.86 higher
(3.29 lower to 4.43 higher)
805
(15 RCTs)
⨁◯◯◯
VERY LOW†‡
A small effect, not clinically relevant, in pain improvement was detected in favour of MT. This analysis excluded two trials (one suspected of publication bias, one used a different scale) which increased heterogeneity levels but did not affect overall efficacy meaningfully.
Adverse events assessed with: no of AE occurred144 per 1.000 121 per 1.000
(79 to 184)
RR 0.84
(0.55 to 1.28)
531
(6 RCTs)
⨁⨁◯◯
LOW†
Pooled data from six studies did not show any difference in AE occurrence between ST and MT.
Drop-outs rate assessed with: no of participants that leaved the study174 per 1.000 171 per 1.000
(134 to 218)
RR 0.98
(0.77 to 1.25)
1238
(11 RCTs)
⨁⨁◯◯
LOW†
Pooled data from 11 trials did not show difference in drop-out rate between ST and MT.
2. ST compared with no treatment
Patient or population: back pain
Intervention: ST
Comparison: No treatment
Outcomes Anticipated absolute effects* (95% CI)Relative effect
(95% CI)
No of participants
(studies)
Certainty of the evidence
(GRADE)
Comments
Risk with no treatment Risk with ST
Pain improvement assessed with: VAS score
Scale from: 0 to 100
MD 5.84
lower
(20.46 lower to 8.78 higher)
177
(3 RCTs)
⨁◯◯◯
VERY LOW†‡¶
Pooled data from three trials, highly inconsistent, showed no differences between ST and no treatment group in pain improvement.
Drop-outs rate assessed with: no of participants that leaved the study150 per 1.000 123 per 1.000
(65 to 233)
RR 0.82
(0.43 to 1.55)
225
(4 RCTs)
⨁◯◯◯
VERY LOW†¶
Very low quality of evidence suggests no differences in drop-out rate between ST and no treatment.
  • GRADE Working Group grades of evidence.

  • High certainty: We are very confident that the true effect lies close to that of the estimate of the effect.

  • Moderate certainty: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.

  • Low certainty: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect

  • Very low certainty: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect

  • *The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).

  • †The majority of trials were judged as poor quality according to AHRQ standards.

  • ‡Most of the studies were small trial

  • §Heterogeneity levels at 85%.

  • ¶Number of participants <400.

  • AE, adverse effect; GRADE, Grading of Recommendations Assessment, Development and Evaluation; MD, Mean difference; RCT, randomised controlled trials; RR, Risk ratio; VAS, Visual Analogue Scale.