Table 2.

Assessment of methodological quality of the studies

	Overall risk-of-bias judgement	Bias arising from the randomization process	Bias due to deviations from intended interventions	Bias due to missing outcome data	Bias in measurement of the outcome	Bias in selection of the reported result
Howell et al., 2018	High	Some concerns	Some concerns	High	Low	Low
Huang et al., 2014	Some concerns	Some concerns	Some concerns	Low	Low	Low
Li et al., 2013	Low	Low	Low	Low	Low	Low
Li et al., 2018	Low	Low	Low	Low	Low	Low
Mendoza et al., 2017	Some concerns	Some concerns	Low	Low	Low	Low
Sabel et al., 2016	Low	Low	Low	Low	Low	Low
Stern et al., 2018	High	Low	Low	High	Low	Low
Wu et al., 2019	High	Low	Low	High	Low	Low

Each domain assigned a judgement of low risk of bias, high risk of bias, or unclear risk of bias