Chart 2. Quality assessment of the included studies using the Cochrane risk of bias tool.

Study	Random sequence generation	Allocation concealment	Blinding of participants and personnel	Blinding of outcome assessment	Incomplete outcome data	Selective reporting	Other bias
Bygdeman and Swahn (1996) 14
Loprinzi et al. (1997) 15
Balk et al. (2002) 32
Labrie et al. (2009) 45
Bachmann and Komi (2010) 52
Oh et al. (2010) 33
Raghunandan et al. (2010) 16
Ekin et al. (2011) 67
Genazzani et al. (2011) 46
Jonasson et al. (2011) 61
Labrie et al. (2011) 27
Le Donne et al. (2011) 28
Lee et al. (2011) 17
Loprinzi et al. (2011) 18
Amato et al. (2013) 34
Grimaldi et al. (2012) 29
Tedeschi and Benvenuti (2012) 35
Chen et al. (2013) 68
Lima et al. (2013) 36
Portman et al. (2013) 53
Zheng et al. (2013) 30
Constantine et al. (2015) 54
Fernandes et al. (2014) 19
Labrie et al. (2014) 47
Lima et al. (2014) 37
Portman et al. (2014) 55
Archer et al. (2015) 48
Bouchard et al. (2015) 49
Goetsch et al. (2015) 65
Labrie et al. (2015) 50
Tungmunsakulchai et al. (2015) 57
Hickey et al. (2016) 20
Jokar et al. (2016) 31
Juliato et al. (2017) 21
Labrie et al. (2016) 51
Melisko et al. (2017) 58
Postigo et al. (2016) 38
Seyyedi et al. (2016) 22
De Souza et al. (2016) 39
Yaralizadeh et al. (2016) 40
Cruz et al. (2018) 63
Malakouti et al. (2017) 41
Nappi et al. (2017) 23
Nazarpour et al. (2017) 59
Suwanvesh et al. (2017) 42
Diem et al. (2018) 24
Golmakani et al. (2019) 66
Mitchell et al. (2018) 25
Nazarpour et al. (2018) 60
Torky et al. (2018) 62
Archer et al. (2019) 56
Ghorbani et al. (2019) 43
Mitchell et al. (2019) 26
Palma et al. (2019) 44
Politano et al. (2019) 64

Key: High risk of bias; Unclear risk of bias; Low risk of bias