Study or subgroup Experimental Control Weight Risk ratio Risk ratio Events Total Events Total M-H, random, 95% CI M-H, random, 95% CI Chen, 2007 [32 ] 28 32 21 32 3.0% 1.33 [1.00, 1.77]
Cui et al.,2005 [34 ] 49 50 25 30 6.6% 1.18 [1.00, 1.39]
Fang et al.,2005 [27 ] 58 65 47 72 5.5% 1.37 [1.13, 1.65] Guo, 2009 [25 ] 56 57 27 30 9.1% 1.09 [0.96, 1.24]
Jia et al.,2010 [26 ] 30 32 21 28 4.1% 1.25 [0.99, 1.58] Kang, 2006 [30 ] 35 36 35 38 10.4% 1.06 [0.95, 1.18] Lin, 2008 [31 ] 30 32 22 30 4.0% 1.28 [1.01, 1.61] Liu, 2010 [35 ] 52 55 40 55 6.2% 1.30 [1.09, 1.55] Lv, 2009 [39 ] 33 35 30 35 7.0% 1.10 [0.94, 1.29] Run, 2001 [37 ] 21 24 14 24 1.8% 1.50 [1.04, 2.17]
Shi and Zhang,1995 [36 ] 17 21 12 20 1.5% 1.35 [0.89, 2.04]
Wang and Yu,2005 [38 ] 62 64 55 64 10.4% 1.13 [1.01, 1.26]
Wu and Luo,2011 [23 ] 33 35 29 35 6.3% 1.14 [0.96, 1.35]
Yan and Mei,2004 [33 ] 55 60 52 60 9.1% 1.06 [0.93, 1.20] Zhang, 2004 [24 ] 36 40 25 40 3.4% 1.44 [1.11, 1.87]
Zhang et al.,2010 [12 ] 77 82 67 82 9.7% 1.15 [1.02, 1.29]
Zheng et al.,2004 [40 ] 24 27 13 22 1.8% 1.50 [1.04, 2.18] Total (95% CI) 747 697 100.0% 1.18 [1.12, 1.24] Total events 696 535
Heterogeneity: Tau² = 0.00; Chi² = 24.82, df = 16 (P = 0.07);
= 36%
Test for overall effect: Z = 6.02 (P < 0.00001)
