Table 1.

The Cochrane Collaboration tool for assessing risk of bias; review of author judgment of risk of bias for each item.

	Sequence generation	Allocation concealment	Blinding of participants and personnel	Blinding of outcome assessors	Incomplete outcome data	Selective outcome reporting	Other sources of bias
Bao et al., 2010 [21]	Low	Low	High	High	Low	Low	Unclear
Belcaro et al., 2014 [22]	Unclear	Unclear	Low	Low	Low	Unclear	High
Brooker et al., 2006 [23]	Unclear	Low	Low	Low	Low	Low	Low
Costa Fortes et al., 2010 [24]	Unclear	Unclear	Low	High	Low	Low	Low
Pawar et al., 2013 [27]	Unclear	High	Unclear	High	High	High	High
Pommier et al., 2004 [25]	Low	Low	Unclear	High	Low	Low	Unclear
Tröger et al., 2014 [26]	Low	Low	High	Unclear	Unclear	Low	Unclear