Table 3.

Cochrane risk of bias summary

Included studies	Random sequence generation	Allocation concealment	Blinding of participants and personnel	Blinding of outcome assessment	Incomplete outcome data	Selective reporting	Other bias
Bansal et al[5], 2010	Low risk	Low risk	High risk	Unclear risk	High risk	High risk	Unclear risk
Rogers et al[24], 2010	Low risk	Low risk	High risk	Unclear risk	High risk	Low risk	Low risk
Rhodes et al[25], 1998	Unclear risk	Unclear risk	High risk	Unclear risk	Low risk	High risk	Unclear risk
Cuschieri et al[26], 1999	Low risk	Unclear risk	High risk	Unclear risk	Low risk	High risk	Unclear risk
Nathanson et al[27], 2005	Low risk	Low risk	High risk	Unclear risk	Low risk	High risk	Unclear risk
Sgourakis et al[28], 2002	High risk	Unclear risk	High risk	Unclear risk	High risk	High risk	Low risk
Noble et al[29], 2009	Low risk	Unclear risk	High risk	Unclear risk	Low risk	High risk	Low risk