Table 3.

Sensitivity analysis of included studies.

Study, year	Statistics with study removed
	Difference in means	Lower limit	Upper limit	Z-value	P value	I 2
Acupuncture versus sham acupuncture
Inoue et al. 2006	−0.5	−0.97	−0.04	2.13	0.03	86%
Maeda et al. 2013	−0.58	−1.08	−0.09	2.31	0.02	87%
Nabeta and Kawakita 2002	−0.61	−1.10	−0.13	2.48	0.01	87%
Su et al. 2010	−0.47	−0.93	−0.02	2.06	0.04	84%
Liu et al. 2014	−0.62	−1.20	−0.04	2.10	0.04	87%
Lu et al. 2010	−0.51	−0.97	−0.05	2.17	0.03	87%
Stival et al. 2014	−0.51	−0.98	−0.04	2.14	0.03	86%
Yang et al. 2012	−0.50	−0.97	−0.03	2.09	0.04	85%
Zhang et al. 2015	−0.72	−1.06	−0.38	4.17	<0.0001	68%
Acupuncture versus analgesic injection
Chen and Li 2012	−1.56	−2.30	−0.82	4.14	<0.0001	51%
Inoue et al. 2009	−1.41	−2.33	−0.49	3.00	0.003	79%
Shin et al. 2013	−1.00	−1.48	−0.53	4.12	<0.0001	0%