Table 4. The risk of bias assessment for the included trials based on the ROB2 tool (n = 8).

D1: randomization process; D2: deviations from intended interventions; D3: missing outcome data; D4: measurement of the outcome; D5: selection of the reported result

Study	D1	D2	D3	D4	D5	Overall
Peck et al. [12,13]	Some concerns	High	High	Low	Some concerns	High
Begum et al. [31]	Some concerns	Low	Low	Low	Some concerns	Some concerns
Ghanei et al. [32]	Some concerns	Low	Low	Low	Some concerns	Some concerns
Lahiji et al. [33]	High	Low	Low	Low	Some concerns	High
Shayanpour et al. [34]	Low	Low	Low	Low	Low	Low
Heydarbaki et al. [35]	Low	Low	Low	Low	Low	Low
Forouhari et al. [36]	Some concerns	Low	High	Low	Some concerns	High
Rafieipoor et al. [37]	Low	Low	Low	Low	Low	Low