Table 2.
Risk of bias of the included studies.
| Included studies | A | B | C | D | E | F | G | Total |
|
| ||||||||
| Darbandi et al., 2012 [9] | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 4 |
|
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| Darbandi et al., 2013 [10] | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 4 |
|
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| Darbandi et al., 2014 [11] | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 4 |
|
| ||||||||
| Gucel et al., 2012 [12] | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 4 |
|
| ||||||||
| Han-1, 2016 [13] | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 7 |
|
| ||||||||
| Han-2, 2016 [13] | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 7 |
|
| ||||||||
| He et al., 2008 [14] | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 5 |
|
| ||||||||
| Hsu et al., 2009 [15] | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 4 |
|
| ||||||||
| Hung et al., 2016 [16] | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 6 |
|
| ||||||||
| Kim et al., 2014 [17] | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 4 |
|
| ||||||||
| Lien et al., 2012 [18] | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 4 |
|
| ||||||||
| Luo, 2006 [19] | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 4 |
|
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| Nourshahi et al., 2009 [20] | 1 | 0 | 0 | 0 | 0 | 1 | 1 | 3 |
|
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| Tong, 2011 [21] | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 6 |
|
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| Xing, 2009 [22] | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 5 |
|
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| Xiong et al., 2016 [23] | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 4 |
|
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| Yeh et al., 2015 [24] | 1 | 1 | 1 | 0 | 0 | 0 | 1 | 4 |
|
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| Yeo et al., 2014 [25] | 1 | 1 | 1 | 0 | 1 | 0 | 1 | 5 |
|
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| Zhang et al., 2012 [26] | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 7 |
|
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| Zhang, 2012 [27] | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 6 |
|
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| Zhao et al., 2011 [28] | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 5 |
|
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| Zhao, 2010 [29] | 1 | 0 | 0 | 0 | 1 | 1 | 1 | 4 |
Note: A, adequate sequence generation; B, concealment of allocation; C, blinding of participants and personnel; D, blinding of outcome assessment; E, incomplete outcome data; F, selective reporting; G, other bias; 1, low risk of bias, the information of the domain was adequate in the text; 0, high risk of bias, the information of the domain was inadequate in the text.