| | Study | Random sequence generation | Allocation concealment | Blinding of participants and investigators | Blinding of outcome assessment | Incomplete outcome data addressed | Selective outcome reporting |
| | Allison et al. 1995, USA | Unclear risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Hsu et al. 2005, Taiwan | Unclear risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Richards et al. 1998, Australia | Unclear risk | Low risk | High risk | Low risk | Low risk | Unclear risk | | He et al. 2008, China | Unclear risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Li et al. 2006, China | Low risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Tong et al. 2011, China | Unclear risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Hsu et al. 2009, Taiwan | Unclear risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Hsieh et al. 2010, Taiwan | Unclear risk | Unclear risk | High risk | Low risk | High risk | Unclear risk | | Hsieh et al. 2011, Taiwan | Unclear risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Abdi et al 2012, Iran | Unclear risk | Unclear risk | High risk | Low risk | High risk | Unclear risk | | Darbandi et al 2012, Iran | Unclear risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | He et al 2012, China | Unclear risk | Unclear risk | High risk | Low risk | Unclear risk | Unclear risk | | Lien et al 2012, Taiwan | Low risk | Low risk | High risk | Low risk | High risk | Unclear risk | | Darbandi et al 2014, Iran | Low risk | Low risk | High risk | Low risk | Low risk | Unclear risk | | Yeh et al. 2015, Taiwan | Low risk | Low risk | High risk | Low risk | High risk | Unclear risk | | Chen et al. 2007, China | Low risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Huang et al. 2011, China | Unclear risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Tang et al. 2009, China | High risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Shi et al, 2006, China | Low risk | Unclear risk | High risk | Low risk | Unclear risk | Unclear risk | | Hsu et al. 2005, Taiwan | Low risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Güçel et al. 2012, Turkey | Low risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Deng et al. 2014, China | Unclear risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Hassan et al. 2014, Egypt | Unclear risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | He et al. 2014, China | Low risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Wang et al. 2013, China | High risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Sujung et al. 2014, South Korea | Low risk | Low risk | High risk | Low risk | Low risk | Unclear risk | | Bu et al. 2007, China | Low risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Shi et al. 2005, China | Low risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Yang et al. 2010, China | High risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Cabioglu et al. 2005, Turkey | Unclear risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Cabioglu et al. 2006, Turkey | Unclear risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Cabioglu et al. 2008, Turkey | Unclear risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Darbandi et al. 2013, Iran | Low risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | | Fogarty et al. 2015, Australia | Unclear risk | Low risk | High risk | Low risk | Low risk | Unclear risk |
|
|
