Table 2.

The influence of individual study on the pooled estimate (HR)

Study omitted	Year	HR	95% CI	Heterogeneity
				I2	P value
None		1.29	0.94-1.76	80	<0.001
Chen [33]	2013	1.25	0.91-1.73	80	<0.001
Chen [16]	2010	1.25	0.90-1.71	80	<0.001
Chen [23]	2011	1.37	0.99-1.88	78	<0.001
Gu [27]	2012	1.27	0.91-1.77	80	<0.001
He [24]	2011	1.26	0.92-1.74	80	<0.001
Jain [28]	2012	1.37	1.00-1.88	78	<0.001
Lan [35]	2013	1.34	0.96-1.87	80	<0.001
Liao [36]	2013	1.27	0.91-1.77	80	<0.001
Liu [25]	2011	1.21	0.89-1.65	78	<0.001
Liu [29]	2012	1.28	0.93-1.76	80	<0.001
Lv [26]	2011	1.35	0.97-1.88	80	<0.001
Wang [37]	2013	1.36	0.98-1.88	77	<0.001
Wu [30]	2012	1.23	0.90-1.69	78	<0.001
Zhang [31]	2012	1.25	0.91-1.73	79	<0.001
Zhang [17]	2009	1.24	0.90-1.70	80	<0.001
Zhuang [32]	2012	1.26	0.91-1.74	80	<0.001
Xu [51]	2014	1.23	0.90-1.70	79	<0.001
Lu [52]	2013	1.36	0.98-1.88	79	<0.001