Table 2 Methodological quality of the randomized controlled trials
Study | Random sequence generation | Allocation concealment | Blinding of participants and personnel | Blinding of outcome assessment | Incomplete outcome data | Selective reporting | Other bias |
|---|---|---|---|---|---|---|---|
Nilsson et al. [10] | Low risk | Low risk | High risk | Low risk | Low risk | Low risk | Low risk |
Gao et al. [11] | Low risk | Low risk | High risk | Low risk | Low risk | Low risk | Low risk |
Park et al. [12] | Low risk | Low risk | High risk | High risk | Low risk | Low risk | Low risk |
Kim et al. [13] | Low risk | Low risk | High risk | High risk | Low risk | Low risk | Low risk |
Lizaur-Utrilla et al. [14] | Low risk | High risk | Low risk | Low risk | Low risk | Low risk | Low risk |
Henricson et al. [15] | Unclear risk | High risk | High risk | Unclear risk | Low risk | Low risk | Low risk |