Studies included | Random sequence generation | Blinding of participants | Blinding of outcome assessment | Incomplete outcome data | Selective reporting | Other bias | Quality grade |
Afsansh et al. [7] | High | Unclear | Low | Low | Low | Low | B |
Kristen et al. [17] | Low | Low | Low | Low | Low | Low | A |
Zeev et al. [8] | Low | Low | Low | Low | Low | Low | A |
Arai et al. [18] | Low | Low | Low | Low | Low | Low | A |
Kristi et al. [16] | Low | unclear | Low | Low | Low | Low | B |
Li et al. [9] | High | Low | Low | Low | Low | Low | B |
Farid et al. [10] | Low | unclear | Low | Low | Low | Low | B |
Spafford et al. [21] | Low | unclear | Low | Low | Low | Low | B |
Kain et al. [11] | Low | unclear | High | Low | Low | Low | B |
Zeev et al. [20] | High | unclear | unclear | Low | Low | Low | B |
W. J. Huang [19] | High | unclear | Low | Low | Low | Low | B |
L. F. Wang et al. [12] | High | unclear | unclear | Low | Low | Low | B |
J. H. Lou [13] | Low | Low | Low | Low | Low | Low | A |
G. Y. Zhang [14] | Low | high | unclear | Low | Low | Low | B |
Q. Xu et al. [15] | High | Low | unclear | Low | Low | Low | B |