Table 2. Risk of bias assessment.

References	Random sequence generation	Allocation concealment	Blinding of participants and personnel	Blinding of outcome assessment	Incomplete outcome data	Selective reporting
Harvey et al. [20]	Unclear	Unclear	High	High	Low	Unclear
Andrivet et al. [17]	Unclear	Unclear	High	High	Low	Unclear
Noppen et al. [21]	Low	Low	High	High	Low	Unclear
Ayed et al. [22]	Low	High	High	High	Low	Unclear
Parlak et al. [18]	Low	Unclear	High	High	Low	Low
Korczynski et al. [19]	Low	Unclear	High	High	Low	Unclear
Roggla et al. [23]	Low	Unclear	High	High	Low	Unclear