Table 2.

Bias assessment of each randomized controlled trial.

Source	Random sequence generation	Allocation concealment	Blinding of participants and personnel	Blinding of outcome assessment	Incomplete outcome data addressed	Selective reporting
Karstoft et al., 2013	Low	Unclear	Low	Low	Low	Low
Terada et al., 2013	Low	Unclear	Low	Low	Low	Low
Mitranun et al., 2014	Unclear	Unclear	Low	Low	Low	Low
Hollekim-Strand et al., 2014	Low	Unclear	Low	Low	High	Low
Maillard et al., 2016	Low	Unclear	Low	Low	Low	Low
Alvarez et al., 2016	Low	Unclear	Low	Low	High	Low
Cassidy et al., 2016	Low	Unclear	Low	Low	Low	Low