Table 2.

Risk of bias summary^*

	Adequate sequence generation	Allocation concealment	Patient blinding	Incomplete outcome data addressed	Free of selective reporting	Baseline compara- bility a	ITT b
An (2010) (33)	Yes	[Yes]	No	[Unclear]C	Yes	Unclear	No
Anastasi (1999) (34)	[Yes]	[Yes]	Yes d	Yes	Yes	Yes	No
Chen (2009) (36)	[No] e	[No]	No	[Unclear]f	Yes	Yes	No
Chen (2011) (35)	Yes	[Yes]	No	[Yes]	Yes	Yes	No
Forbes (2005) (37)	Yes	[Yes]	Yes g	Yes	Yes	Yes	Yes
Lembo (2009) (38)	Yes	Yes	Yes h	Yes	Yes	Yes	Yes
Li (2009) (39)	[No] e	[No]	No	[Unclear]C	Yes	Yes	No
Liu (1997) (40)	[Unclear]i	[Unclear]	No	[Unclear]C	Yes	Unclear	No
Liu (2010) (41)	[Unclear]i	[No]	No	[Unclear]j	Yes	Unclear	No
Lowe (2000) (42)	[Yes]	[Yes]	Uncleark	UnclearC	Yes	Yes	Unclear
Reynolds (2008) (43)	[Yes]	[Yes]	No	Yes	No	Yes	Yes
Schneider (2006) (44)	[Yes]	Yes	Yes h	Yes	Yes	Yes	No
Shi (2010) (45)	[Yes]	[Yes]	No	Yes	Yes	Yes	Yes
Sun (2011) (46)	[Yes]	[No]	No	Yes	Yes	Yes	No
Xiong (2008) (47)	[Yes]	[No]	No	[Unclear]C	Yes	Unclear	No
Xue (2009) (48)	[Unclear]i	[Unclear]	No	Yes	Yes	Yes	No
Zeng (2010) (49)	Yes	[Yes]	No	Yes	Yes	Yes	No

^*We followed the Cochrane Handbook criteria (28) for making judgments about the risk of bias for each of the 6 domains in the Cochrane Risk of Bias tool. Additional data obtained from RCT authors is enclosed in brackets to allow such data to be differentiated from the data included only in the publications.

^aFor the baseline comparability criterion to score “Yes”, a comparison of the symptom scores between the treatment and control group(s) at baseline needed to be reported.

^bFor the ITT criterion to score “Yes”, an intention-to-treat analysis needed to be reported.

^CIn these trials, the authors did not report the numbers of drop-outs in their publication, and did not have records of the numbers of drop-outs to provide during the telephone interviews.

^dFor the sham control, penetrating needles were superficially inserted at nonpoints which were 2-3 cm away from the true points, and placebo moxibustion was performed above the same sham points without generating a heat sensation.

^eThe authors of these trials confirmed in telephone interviews that a few patients were non-randomly assigned to achieve identical sized treatment groups.

^fFor this trial, the authors endeavored to maintain equal group sizes, by eliminating participants who withdrew during the trial and replacing them with new patients, and the number of such replacements was not recorded by the author.

^gFor the sham control, acupuncture needles were inserted at areas on the body that do not correspond to acupuncture points and are deemed to have no therapeutic value. The points and needling technique were varied somewhat each week, as was also done in the true acupuncture group, who received individualized point selection.

^hFor the sham control in these trials, the Streitberger placebo needle was used, which has been previously validated as a sufficiently credible sham (29). The Streitberger needles were placed close to the genuine acupuncture points in both trials. In both trials, the participants were acupuncture naïve.

ⁱThis criterion was scored as “Unclear” because the authors of these 3 trials were unable to explain how equal sample sizes were achieved.

^jFor this trial, the authors reported no drop-outs, which would be unusual in a 4 week trial of 300 participants.

^kThe sham control used in this trial was judged to have been potentially detectable as a fake treatment by the trial participants. The sham procedure involved tapping a blunt needle on the skin and then taping the needle in place. Although this procedure was described as “validated”, we are unaware of a validation study for this procedure. Also, in the trial report there was no description of whether or not the patients were required to have never previously used acupuncture, and there were no reported tests for checking the success of the blinding.