Table 2. Assessment of risk of bias among included studies.

Studies	Random sequence generation	Allocation concealment	Blinding of participants and personnel	Blinding of outcome assessment	Incomplete outcome data	Selective reporting
Aldamiz-Echevarría et al., 2007 (10)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Atienza et al., 2004 (11)	Low risk	Low risk	Low risk	Unclear risk	Low risk	Low risk
Blue et al., 2001 (12)	Low risk	Low risk	Low risk	Unclear risk	Low risk	Low risk
Boyde et al., 2018 (13)	Low risk	Low risk	Low risk	High risk	Low risk	Low risk
Brian et al., 2009 (14)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Brotons et al., 2009 (15)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Cañon-Montañez et al., 2013 (16)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Cui et al., 2019 (17)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Davis et al., 2012 (18)	Low risk	Unclear risk	Low risk	Low risk	Low risk	Low risk
De Souza et al., 2014 (19)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
DeBusk et al., 2004 (20)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Delaney et al., 2013 (21)	Low risk	Low risk	Low risk	Unclear risk	Low risk	Low risk
Dewalt et al., 2006 (22)	Low risk	Low risk	Low risk	High risk	Low risk	Low risk
Domingues et al., 2011 (23)	Low risk	Unclear risk	Low risk	Unclear risk	Unclear risk	Low risk
Doughty et al., 2002 (24)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Dracup et al., 2014 (25)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Ducharme et al., 2005 (26)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Gámez-López et al., 2012 (27)	Low risk	Unclear risk	Low risk	Low risk	Unclear risk	Low risk
González-Guerrero et al., 2014 (28)	Low risk	Low risk	Low risk	Unclear risk	Low risk	Low risk
Hägglund et al., 2015 (29)	Low risk	Unclear risk	Low risk	Unclear risk	Low risk	Low risk
Holland et al., 2007 (30)	Low risk	Low risk	Low risk	Unclear risk	Low risk	Low risk
Jaarsma et al., 1999 (31)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Jaarsma et al., 2011 (32)	Low risk	Low risk	Low risk	Unclear risk	Low risk	Low risk
Jerant et al., 2001(33)	Low risk	Low risk	Low risk	Unclear risk	Low risk	Low risk
Kato et al., 2016 (34)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Kimmelstiel et al., 2004 (35)	Low risk	High risk	Low risk	Low risk	Low risk	Low risk
Koelling et al., 2005 (36)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Krumholz et al., 2002 (37)	Low risk	Unclear risk	Low risk	Unclear risk	Low risk	Unclear risk
Leventhal et al., 2011 (38)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Mau et al., 2017 (39)	Low risk	High risk	Low risk	Unclear risk	Low risk	Low risk
Melin et al., 2018 (40)	Low risk	High risk	Low risk	Low risk	Low risk	Low risk
Naylor et al., 2004 (41)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Negarandeh et al., 2019 (42)	Low risk	Low risk	Low risk	Unclear risk	Low risk	Low risk
Otsu et al., 2011 (43)	Low risk	Unclear risk	Low risk	High risk	Low risk	Low risk
Ramachandran et al., 2007 (44)	Low risk	Low risk	Low risk	High risk	Low risk	Low risk
Rodríguez-Gázquez et al., 2012 (45)	Low risk	Low risk	Low risk	Unclear risk	Low risk	Low risk
Ruschel et al., 2018 (46)	Low risk	Unclear risk	Low risk	Low risk	Low risk	Low risk
Sethares et al., 2004 (47)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Stewart et al., 2015 (48)	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Tomita et al., 2009 (49)	Low risk	Unclear risk	Low risk	Unclear risk	Low risk	Low risk
Tsuchihashi‐Makaya et al. 2013 (50)	Low risk	Unclear risk	Low risk	Unclear risk	Low risk	Low risk
Walkefield et al., 2008 (51)	Low risk	Low risk	Low risk	Unclear risk	Low risk	Low risk
Wierzchowiecki et al., 2006 (52)	Low risk	Unclear risk	Low risk	Unclear risk	Unclear risk	Low risk
Wright et al., 2003 (53)	Low risk	Unclear risk	Low risk	Unclear risk	Low risk	Low risk
Yu et al., 2015 (54)	Low risk	Low risk	Low risk	Unclear risk	Low risk	Low risk