Table 2 Risk of bias summary in included studies
Bias risk | Tekgündüz et al., 2014 [16] | Shaeri et al., 2017 [19] | Mohamed & Ahmed, 2018 [15] | Ghasemi et al., 2019 [20] | Choi et al., 2015 [17] | Fazli et al., 2017 [18] | Karbandi et al., 2013 [13] | Fouda et al., 2018 [14] |
|---|---|---|---|---|---|---|---|---|
Random sequence generation (selection bias) | ? | Y | Y | Y | N | Y | Y | Y |
Allocation concealment | ? | ? | ? | ? | ? | ? | ? | ? |
Blinding of participant and personnel | ? | N | ? | ? | ? | N | ? | ? |
Blinding of outcome assessment | ? | N | ? | ? | ? | N | ? | ? |
Incomplete outcome data | Y | Y | Y | Y | Y | N | Y | Y |
Selective reporting | Y | Y | ? | ? | ? | Y | ? | ? |