(b) By omitting one study at a time

Study omitted	Risk Ratio (95%CI)	P-value	I 2 -value, %
Huang et al. (2015)	1.22 [1.11, 1.34]	P<0.0001	35%
Huo et al. (2014)	1.23 [1.12, 1.36]	P<0.0001	41%
Li et al. (2016)	1.25 [1.13, 1.38]	P<0.0001	41%
Lin et al. (2018)	1.23 [1.11, 1.35]	P<0.0001	39%
Qian et al. (2016)	1.24 [1.12, 1.37]	P<0.0001	42%
Wan et al. (2017)	1.25 [1.13, 1.38]	P<0.0001	43%
Wang et al. (2018)	1.26 [1.14, 1.39]	P<0.00001	32%
Wu et al. (2012)	1.21 [1.11, 1.33]	P<0.0001	31%
Xing et al. (2014)	1.26 [1.13, 1.39]	P<0.0001	40%
You et al. (2015)	1.21 [1.11, 1.31]	P<0.00001	17%
Zhang et al. (2016)	1.26 [1.15, 1.39]	P<0.00001	30%
Zhang et al. (2017)	1.23 [1.12, 1.36]	P<0.0001	40%
Zhou et al. (2013)	1.24 [1.12, 1.38]	P<0.0001	43%
Combined	1.24 [1.13, 1.36]	P<0.00001	37%