Table 2.

Risk of Bias. +: Low risk, !: Some concerns, −: High risk, D1: Randomisation process, D2: Deviations from the intended interventions, D3: Missing outcome data, D4: Measurement of the outcome, D5: Selection of the reported result.

Intention-to-Treat	D1	D2	D3	D4	D5	Overall
Akkasheh 2016 [32]
Allen 2016 [59]
Bagga 2018 [19]
Bagga 2019 [18]
Benton 2007 [60]
De Lorenzo 2017 [61]
Dickerson 2018 [73]
Diop 2008 [62]
Ghaderi 2019 [34]
Ho 2021 [55]
Hwang 2019 [35]
Karbownik 2020 [64]
Kato-Kataoka 2016 [37]
Kazemi 2019 [38]
Kelly 2017 [65]
Nishida 2017 [43]
Nishida 2019 [44]
Östlund-Lagerström 2016 [67]
Patterson 2020 [68]
Raygan 2018 [48]
Romijn 2017 [79]
Sanchez 2017 [78]
Sashihara 2013 [49]
Sawada 2017 [50]
Steenbergen 2015 [72]
Xiao 2020 [56]
Per-protocol	D1	D2	D3	D4	D5	Overall
Adikari 2020 [54]
Chung 2014 [33]
Dickerson 2014 [74]
Eskandarzadeh 2021 [30]
Gualtieri 2020 [63]
Inoue 2018 [36]
Kobayashi 2019 [39]
Lew 2019 [40]
Messaoudi 2011 [66]
Mohammadi 2016 [41]
Murata 2018 [42]
Nishihira 2014 [45]
Ohsawa 2018 [46]
Papalini 2019 [20]
Rao 2009 [75]
Raygan 2019 [47]
Reininghaus2020 [69]
Roman 2018 [70]
Romijn 2017 [79]
Rudzki 2019 [71]
Shinkai 2013 [58]
Takada 2016 [52]
Takada 2017 [51]
Tillisch 2013 [21]
Tran 2019 [77]
Wang 2019 [22]
Yamamura 2009 [53]
Zhang 2021 [57]
	Low risk
	Some concerns
	High risk
D1	Randomisation process
D2	Deviations from the intended interventions
D3	Missing outcome data
D4	Measurement of the outcome
D5	Selection of the reported result