Table 1.

Risk of bias assessment for the quasi-experimental trials.

Reference	Q1a	Q2b	Q3c	Q4d	Q5e	Q6f	Q7g	Q8h	Q9i	Quality grade
Xie (2011) [31]	Yj	Uk	U	Y	Y	Y	Y	Y	Y	A
Chiu et al (2016) [33]	Y	U	Y	Y	Y	Y	Y	Y	Y	A
Lee and Kim (2019) [32]	Y	U	U	Y	Y	U	Y	Y	Y	A
Bevilacqua et al (2021) [34]	Y	U	U	Y	Y	Y	Y	Y	Y	A
Chang et al (2021) [35]	Y	U	U	Y	Nl	U	Y	Y	Y	B

^aQ1: clear cause and effect.

^bQ2: similar at baseline.

^cQ3: similar treatment other than the intervention.

^dQ4: control group.

^eQ5: multiple measurements.

^fQ6: follow-up description.

^gQ7: the same outcome measurement.

^hQ8: reliability of outcome measurements.

ⁱQ9: appropriate statistical analysis.

^jY: yes.

^kU: unclear.

^lN: no.