Table 3.

Risk of bias and quality assessment of the included studies

Author and year	Sequence generation	Allocation concealment	Blinded method	Outcome blinded	Result data integrity	Selective reporting	Other bias	Jadad score
Liu et al. 2019 [38]	Central randomisation system, low	Low	Unclear	Low	Low	No, low	Unclear	3
Chen et al. 2016 [39]	Central randomisation system, low	Low	Unclear	Unclear	Low	No, low	Unclear	3
Shi et al. 2015 [40]	Random number table, low	Unclear	Unclear	Unclear	Low	No, low	Unclear	2
Wang et al. 2017 [41]	Central randomisation system, low	Low	Unclear	Unclear	Low	No, low	Unclear	2
Wang et al. 2016 [42]	Central randomisation system, low	Low	Unclear	Unclear	Low	No, low	Unclear	3
Hong et al. 2015 [43]	Random number table, low	Unclear	Unclear	Unclear	Low	No, low	Unclear	3
Zhang et al. 2015 [44]	Central randomisation system, low	Low	Unclear	Unclear	Low	No, low	Unclear	3
Zhang et al. 2015 [45]	Central randomisation system, low	Low	Unclear	Unclear	Low	No, low	Unclear	3