(b) By omitting one study at a time

Study omitted	Standardized Mean Difference (95%CI)	P-value	I 2-value, %
Huo et al. (2014)	-1.17 [-1.57, -0.77]	P<0.00001	76%
Li et al. (2016)	-1.10 [-1.48, -0.73]	P<0.00001	75%
Lin et al. (2018)	-1.07 [-1.43, -0.71]	P<0.00001	73%
Su et al. (2017)	-1.09 [-1.46, -0.71]	P<0.00001	74%
Wan et al. (2017)	-1.16 [-1.56, -0.76]	P<0.00001	76%
Xing et al. (2014)	-1.11 [-1.50, -0.72]	P<0.00001	75%
You et al. (2015)	-1.09 [-1.46, -0.72]	P<0.00001	74%
Zhang et al. (2016)	-1.25 [-1.46, -1.03]	P<0.00001	12%
Zhou et al. (2013)	-1.17 [-1.56, -0.77]	P<0.00001	76%
Combined	-1.13 [-1.48, -0.78]	P<0.00001	73%