Table 2. Risk for bias assessment in selected randomized controlled trials.

First authorref	Concealment of randomization	Stopped early	Participants blinded	Health care providers blinded	Data collectors blinded	Outcome assessors blinded
Chu et al.25	Yes	No	Yes	Yes	Not informed	Not informed
Basu et al.26, 27, 28, 29	Yes	No	Yes	No	Not informed	Not informed
Vieira Senger et al.30	Yes	No	No	No	Not informed	Not informed
Belcaro et al.31	Not informed	No	Yes	No	Not informed	Not informed
Yang et al.32	Yes	No	Yes	Yes	Not informed	Not informed