Table 2.

Assessment of risk of bias.

Study	Sequence generation	Allocation concealment	Blinding of participants and personnel	Blinding of outcome assessors	Incomplete outcome data	Selective reporting	Other bias
Berk et al. [9]	Low	Low	Low	Low	Low	Low	Low
Magalhães et al. [10]	Low	Low	Low	Low	Low	Low	Low
Berk et al. [11]	Low	Low	Low	Low	Low	Low	Low
Ellegaard et al. [12]	Low	Low	Low	Low	Low	Low	Low
Frangou et al. [14]	Low	Low	Low	Low	Low	Low	High
Stoll et al. [13]	Low	Low	Low	Low	Low	Low	Low
Hirashima et al. [15]	High	High	High	High	Low	Low	Low
Mehrpooya et al. [16]	Low	Low	Low	Low	Low	Low	Low
Toniolo et al.(2018)	Low	Low	Low	Low	Low	Low	Low
Marsh et al. [20]	Low	Low	Low	Low	Low	Low	Low
Chengappa et al. [18]	Low	Low	Low	Low	Low	Low	Low
Evins et al. [19]	Low	Low	Low	Low	Low	Low	Low
Brennan et al. [21]	Low	Low	Low	Low	Low	Low	Low