Table 2

Risk of Bias assessment of the included trials, according to the criteria by the Cochrane Back and Neck Group []
Study authors1. Was the method of randomization 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 randomized participants analyzed in the group to which they were allocated?8. Are reports of the study free of suggestion of selective outcome reporting?9. Were groups similar at regarding the most important prognostic indicators?10. Were co-interventions 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 bias unlikely?Overall risk of bias
Bodes-Pardo et al. []YesUnsureUnsureNoUnsureYesYesYesYesYesYesYesYesUnsure
Chaibi et al. []YesYesNoNoNoNoYesYesNoYesUnsureYesYesHigh
Dunning et al. []YesYesNoNoNoYesYesYesYesYesYesYesYesLow
Esin et al. []YesUnsureUnsureNoNoNoUnsureYesYesUnsureUnsureYesUnsureHigh
Haas et al. []YesYesNoNoNoYesYesYesYesYesYesYesYesLow
Haas et al. []YesYesNoNoNoYesYesYesYesYesYesYesYesLow
Hall et al. []YesUnsureYesNoYesYesYesYesYesNoUnsureYesYesHigh
Jafari et al. []YesUnsureNoNoNoYesYesYesYesYesUnsureYesYesUnsure
Jull et al. []YesUnsureNoNoNoYesYesYesYesNoYesYesYesHigh
Malo-Urriès et al. []YesYesNoNoNoYesYesYesYesYesYesYesYesLow
Nilsson et al. []YesYesNoNoNoYesYesYesYesYesYesYesYesLow
Sedighi et al. []UnsureUnsureNoNoNoYesYesYesYesYesYesYesYesUnsure
Sharma et al. []YesUnsureNoNoNoYesUnsureYesUnsureUnsureUnsureYesUnsureUnsure
von Piekartz et al. 2011 []YesYesNoNoNoYesYesYesYesUnsureYesYesYesUnsure
Yang and Kang []UnsureUnsureNoNoNoNoUnsureYesUnsureUnsureUnsureYesUnsureHigh
Youssef and Shanb []YesYesNoNoNoYesYesYesYesYesYesYesYesLow
Abdel et al. []YesYesNoNoNoYesYesYesYesYesYesYesYesLow
Dunning et al. []YesYesNoNoNoYesYesYesYesYesYesYesYesLow
Lerner-Lentz et al. []YesYesNoNoNoYesYesYesYesYesYesUnsureYesUnsure
Moustafa et al. []YesYesNoNoNoYesYesNoYesYesYesYesYesHigh

Studies were considered as overall low-RoB if no individual domain was rated as “high” or “unsure” RoB. Studies which scored “unsure”, but not “high”, for one or more items, were considered as overall unsure RoB, and “high” if any individual item was rated as high RoB