Variable	Total RCTs, n	Pts randomly assigned, n	Effect size (95% CI)	I2,%	P value for interaction†	Not met‡
	All trials	9	1835	‐0.28 (‐0.45,‐0.11)	63.9	‐	‐
Methodological variables
	Generation of random sequence					0.141	SS
	Adequate	7	1649	‐0.25 (‐0.45,‐0.05)	69
	Unclear or no	2	186	‐0.42 (‐0.71,‐0.13)	0
	Allocation concealment					0.215	SSFi
	Adequate	6	1587	‐0.26 (‐0.48,‐0.04)	74.2
	Unclear	3	248	‐0.36 (‐0.61,‐0.11)	0
	Blinding success					0.042	BSSV
	Yes	5	1221	‐0.15 (‐0.28,‐0.01)	14.5
	Uncertain	4	614	‐0.47 (‐0.84,‐0.10)	77.5
	Intention‐to‐treat analysis					0.532	FiFoSST
	Yes	4	1319	‐0.35 (‐0.63,‐0.07)	80.7
	Unclear or no	5	516	‐0.20 (‐0.43,0.03)	35.2
Clinical variables	Sufficient number of sessions delivered over an adequate treatment duration					0.047	FoT
	Yes	7	1567	‐0.34 (‐0.54, ‐0.15)	66.1
	No	2	268	0.01 (‐0.23, 0.25)	0
	Electrical stimulation was used with the acupuncture					0.042	BSSV met
	Yes	4	614	‐0.50 (‐0.81,‐0.20)	66
	No	5	1215	‐0.11 (‐0.29,0.07)	42.3
	Physiological activity of sham, as judged by acupuncturist					0.042	BSSV
	Likely	5	1221	‐0.15 (‐0.28,‐0.01)	14.5
	Not likely	4	614	‐0.47 (‐0.84,‐0.10)	77.5
	Formula versus flexible formula for point selection					0.057	BFiSSTV used formula
	Formula	6	716	‐0.39 (‐0.66,‐0.12)	72.8
	Flexible formula	3	1119	‐0.14 (‐0.34,0.05)	77