Table 2 Assessment of methodological quality of included studies
Study | Random allocation | Hidden distribution | Blind method | Incomplete outcome data | Selective reporting of results | Other bias | Quality grade |
|---|---|---|---|---|---|---|---|
Buvanendran [12] | Randomized | No clear | Double-blind | Low | Low | Low | C |
Rasmussen [13] | Randomized | No clear | Double-blind | Low | Low | Low | B |
Viscusi a [14] | Randomized | No clear | Double-blind | Low | Low | Low | B |
Viscusi b [14] | Randomized | No clear | Double-blind | Low | Low | Low | B |
Ittichaikulthol a [15] | Randomized | No clear | No clear | Low | Low | Low | C |
Ittichaikulthol b [15] | Randomized | No clear | No clear | Low | Low | Low | C |
Li [16] | Randomized | No clear | No clear | Low | Low | Low | C |
Ye [17] | Randomized | No clear | No clear | Low | Low | Low | C |
Zhou [18] | Randomized | No clear | No clear | Low | Low | Low | C |
Jiang [19] | Randomized | No clear | No clear | Low | Low | Low | C |
Rawal a [20] | Randomized | No clear | Double-blind | Low | Low | Low | B |
Rawal b [20] | Randomized | No clear | Double-blind | Low | Low | Low | B |
Xu [21] | Randomized | No clear | No clear | Low | Low | Low | C |
Munteanu a [22] | Randomized | No clear | Double-blind | Low | Low | Low | A |
Munteanu b [22] | Randomized | No clear | Double-blind | Low | Low | Low | A |
Ding a [23] | Randomized | No clear | No clear | Low | Low | Low | C |
Ding b [23] | Randomized | No clear | No clear | Low | Low | Low | C |
Camu [24] | Randomized | No clear | Double-blind | Low | Low | Low | A |
Mu [25] | Randomized | No clear | Double-blind | Low | Low | Low | A |
Wang [26] | Randomized | No clear | No clear | Low | Low | Low | C |
Yang [27] | Randomized | No clear | Double-blind | Low | Low | Low | C |
Bian [28] | Randomized | No clear | Double-blind | Low | Low | Low | B |