Table 3.

Risk of bias for individual studies

Reference	Randomization process	Deviations from the intended interventions	Missing outcome data	Measurement of the outcome	Selection of the reported result	Overall
Acar et al (2019)20	Low	Low	Low	Low	Low	Low
Anderson et al (2014)21	Low	Low	Low	Low	Low	Low
Barton et al (2015)22	Low	Low	Low	Low	Low	Low
Davis et al (2017)33	Low	Low	Low	Low	Low	Low
Diekmann et al (2019)34	Some concerns	Low	Low	Low	Low	Some concerns
Djuric et al (2009)35	Some concerns	Low	Low	Low	Low	Some concerns
Fitó et al (2014)23	High	Low	High	Low	Some concerns	High
Garcia-Perez et al (2017)36	Low	Low	Low	Low	Low	Low
Jennings et al (2020)37	Some concerns	Low	Low	Low	Low	Some concerns
Khakimov et al (2016)24	Low	Low	Low	Low	Low	Low
Lederer et al (2019)38	Low	Low	Low	Low	Low	Low
Marin et al (2011)39	Some concerns	Low	Low	Low	Low	Some concerns
McClure et al (2019)25	Some concerns	Low	Low	Low	Low	Some concerns
Meslier et al (2020)40	Some concerns	Low	Low	Low	Low	Some concerns
Michielsen et al (2019)41	Some concerns	Low	Low	Low	Low	Some concerns
Miller et al (2005)27	Some concerns	Low	Low	Low	Low	Some concerns
Miller et al (1998)26	Some concerns	Low	Low	Low	Low	Some concerns
Navarro et al (2019)28	Low	Low	Low	Low	Low	Low
Nowson et al (2009)42	Some concerns	Low	Low	Low	Low	Some concerns
Park et al (2019)43	Some concerns	Low	Low	Low	Low	Some concerns
Poulsen et al (2014)29	Low	Low	Low	Low	Low	Low
Rådjursöga et al (2018)44	Some concerns	Low	Low	Low	Low	Some concerns
Rebholz et al (2018)30	Low	Low	Low	Low	Low	Low
Reidlinger et al (2015)45	Low	Low	Low	Low	Low	Low
Shin et al (2019)46	Some concerns	Low	Low	Low	Some concerns	Some concerns
Trimigno et al (2020)31	Low	Low	Low	Low	Low	Low
Tuomainen et al (2019)47	Some concerns	Low	Low	Low	Low	Some concerns
Vázquez-Fresno et al (2015)32	Some concerns	Low	Low	Low	Low	Some concerns
Wellington et al (2019)48	Low	Low	Low	Low	Low	Low
Zhu et al (2020)49	Some concerns	Low	Low	Low	Low	Some concerns