Table 2.

Effect size and GRADE quality of evidence

Certainty assessment							No. of patients		Effect	Certainty	Importance
No. of studies	Study design	Risk of bias	Inconsistency	Indirectness	Imprecision	Other considerations	Real acupuncture	Sham acupuncture	Absolute (95% CI)
Pain changes after treatment (VAS, 0–10 cm scale) – real acupuncture vs sham acupuncture
9	Randomized trials	Not seriousa	Seriousb	Not seriousc	Not seriousd	Nonee	266	262	MD 1.04 lower (1.70 lower to 0.38 lower)	⊕⊕⊕◯ Moderate	Critical
Pain changes after treatment (VAS, 0–10 cm scale) – real MA vs sham MA
7	Randomized trials	Not seriousa	Seriousb	Not seriousc	Not seriousd	Nonee	213	211	MD 1.14 lower (2.18 lower to 0.09 lower)	⊕⊕⊕◯ Moderate	Critical
Pain changes after treatment (VAS, 0–10 cm scale) – real EA vs sham EA
2	Randomized trials	Not seriousa	Not seriousf	Not seriousc	Seriousg	Publication bias strongly suspectedh	53	51	MD 0.94 lower (1.17 lower to 0.72 lower)	⊕⊕◯◯ Low	Critical
Pain changes after treatment (SF-MPQ scale) – real MA vs sham MA
2	Randomized trials	Not seriousa	Not seriousf	Not seriousc	Seriousg	Publication bias strongly suspectedh	32	38	MD 1.23 lower (4.74 lower to 2.27 higher)	⊕⊕◯◯ Low	Critical
FIQ changes after treatment – real acupuncture vs sham acupuncture
4	Randomized trials	Not seriousa	Seriousb	Not seriousc	Seriousg	Nonee	152	155	MD 13.39 lower (21.69 lower to 5.1 lower)	⊕⊕◯◯ Low	Critical
FIQ changes after treatment – real MA vs sham MA
3	Randomized trials	Not seriousa	Not seriousf	Not seriousc	Seriousg	Nonee	127	131	MD 16.72 lower (22.51 lower to 10.94 lower)	⊕⊕⊕◯ Moderate	Critical
FIQ changes after treatment – real EA vs sham EA
1	Randomized trials	Not seriousi	Not seriousj	Not seriousc	Seriousg	Publication bias strongly suspectedh	25	24	MD 2.7 lower (9.06 lower to 3.66 higher)	⊕⊕◯◯ Low	Critical
Long-term effect of pain changes (VAS, 0–10 cm scale) – real acupuncture vs sham acupuncture
3	Randomized trials	Not seriousa	Seriousb	Not Seriousc	Seriousg	Nonee	122	129	MD 1.58 lower (2.72 lower to 0.44 lower)	⊕⊕◯◯ Low	Critical
Long-term effect of pain changes (VAS, 0–10 cm scale) – real MA vs sham MA
2	Randomized trials	Not seriousa	Seriousb	Not seriousc	Seriousg	Publication bias strongly suspectedh	97	105	MD 2.06 lower (3.49 lower to 0.63 lower)	⊕◯◯◯ Very low	Critical
Long-term effect of pain changes (VAS, 0–10 cm scale) – real EA vs sham EA
1	Randomized trials	Not seriousi	Not seriousj	Not seriousc	Seriousg	Publication bias strongly suspectedh	25	24	MD 0.6 lower (1.78 lower to 0.58 higher)	⊕⊕◯◯ Low	Critical
Long-term effect of FIQ changes – real acupuncture vs sham acupuncture
3	Randomized trials	Not seriousa	Seriousb	Not seriousc	Seriousg	Nonee	122	129	MD 12.92 lower (24.92 lower to 0.93 lower)	⊕⊕◯◯ Low	Critical
Long-term effect of FIQ changes – real MA vs sham MA
2	Randomized trials	Not seriousa	Not seriousf	Not seriousc	Seriousg	Publication bias strongly suspectedh	97	105	MD 18.96 lower (26.69 lower to 11.23 lower)	⊕⊕◯◯ Low	Critical
Long-term effect of FIQ changes – real EA vs sham EA
1	Randomized trials	Not seriousi	Not seriousj	Not seriousc	Seriousg	Publication bias strongly suspectedh	25	24	MD 3.0 lower (8.98 lower to 2.98 higher)	⊕⊕◯◯ Low	Critical
Pain changes after treatment (VAS, 0–10 cm scale) – real acupuncture vs conventional medication
2	Randomized trials	Seriousk	Not seriousf	Not seriousc	Seriousg	Publication bias strongly suspectedh	49	49	MD 1.81 lower (2.43 lower to 1.18 lower)	⊕◯◯◯ Very low	Critical

Notes:

^a<25% of studies had high risk of bias.

^bI² is >50%.

^cDirect comparison and outcomes.

^dTotal sample size is >400.

^eNo clear publication bias was detected.

^fI² is <50%.

^gTotal sample size is <400.

^hOnly one study or two studies consider potential publication bias.

ⁱThe study had low risk of bias.

^jOnly one study and no inconsistency.

^kTwo studies had high risk of bias.

Abbreviations: EA, electro-acupuncture; FIQ, fibromyalgia impact questionnaire; MA, manual acupuncture; MD, mean difference; SF-MPQ, short form of McGill Pain Questionnaire.