Table 1

Risk of bias assessment using the criteria from the Cochrane Back Review Group

1. Was the method of randomisation adequate?2. Was the treatment allocation concealed?3. Was the patient blinded to the intervention?4. Was the care provider blinded to the intervention?5. Was the outcome assessor blinded to the intervention?6. Was the drop-out rate described and acceptable?7. Were all randomised participants analysed in the group to which they were allocated?8. Are reports of the study free of suggestion of selective outcome reporting?9. Were the groups similar at baseline regarding the most important prognostic indicators?10. Were cointerventions avoided or similar?11. Was the compliance acceptable in all groups?12. Was the timing of the outcome assessment similar in all groups?13. Are other sources of potential bias unlikely?Score (0/13)
Aboagye et al 39 UnclearUnclearNoNoNoNoYesYesNoUnclearUnclearYesYes 4
Bello et al 40 YesYesUnclearNoUnclearNoYesUnclearYesUnclearNoYesYes 6
Bosmans et al 34 YesYesNoNoNoYesYesNoYesYesNoYesYes 8
Carr et al 41 YesUnclearNoNoNoNoYesUnclearYesUnclearNoYesYes 5
Cherkin et al 42 YesUnclearNoNoNoYesYesUnclearYesYesYesYesYes 8
Chuang et al 43 YesYesNoNoNoYesYesYesYesYesNoYesYes 9
Critchley et al 44 YesYesNoNoNoNoYesYesYesYesUnclearYesYes 8
van Dongen et al 38 YesYesNoNoNoNoYesNoYesYesUnclearYesYes 7
Henchoz et al 45 YesYesNoNoNoNoYesYesYesYesNoYesYes 8
Hlobil et al 46 YesYesNoNoNoYesYesYesYesYesYesYesYes 10
Hollinghurst et al 47 YesYesNoNoNoNoYesYesYesUnclearYesYesYes 8
Hurley et al 48 YesYesNoNoNoYesYesYesYesYesNoYesYes 9
Korthals-de Bos et al 35 YesYesNoNoNoYesYesYesYesNoYesYesYes 9
Leininger et al 36 YesYesNoNoNoYesYesYesYesYesYesYesYes 10
Manca et al 55 YesYesNoNoNoYesYesYesYesYesYesYesYes 10
van der Roer et al 53 YesYesNoNoNoYesYesNoYesYesNoYesYes 8
Rosenfeld et al 37 YesUnclearNoNoNoYesYesYesYesNoYesYesYes 8
Seferlis et al 49 UnclearUnclearNoNoNoNoYesYesUnclearUnclearYesYesYes 5
Smeets et al 50 YesYesNoNoNoYesYesYesYesYesNoYesUnclear 8
Torstensen et al 52 UnclearUnclearNoNoNoYesYesUnclearYesUnclearUnclearYesYes 5
UK BEAM51 UnclearYesNoNoNoNoYesYesYesUnclearYesYesYes 7
Wright et al 54 YesYesNoNoNoYesNoUnclearNoUnclearUnclearYesYes 5