Table 6 Risk of bias assessment in the randomized controlled trials

From: Effects of Zinc Supplementation on Cardiometabolic Risk Factors: a Systematic Review and Meta-analysis of Randomized Controlled Trials

Author (year) Sequence generation Allocation concealment Blinding of participants and personnel Blinding of outcome assessors Incomplete outcome data Selective reporting Other sources of bias Overall risk of bias
Seet 2011 Unclear risk Unclear risk Unclear risk Unclear risk Low risk Low risk Low risk Poor quality
Anderson 2001 Unclear risk Unclear risk Unclear risk Unclear risk Low risk High risk Unclear risk Poor quality
Nascimento-Marreiro 2006 Unclear risk Unclear risk Low risk Unclear risk Low risk Unclear risk Unclear risk Poor quality
Foster 2013 Low risk Low risk Low risk Unclear risk Low risk Low risk Low risk Fair quality
Karamali 2015 Low risk Low risk Low risk Low risk High risk Low risk Low risk Fair quality
Oh 2008 Unclear risk Unclear risk Unclear risk Unclear risk Low risk High risk Unclear risk Poor quality
Payahoo 2013 Low risk Low risk Low risk Low risk Unclear risk Low risk Unclear risk Poor quality
Parham 2008 Unclear risk Unclear risk Unclear risk Unclear risk Low risk Unclear risk Low risk Poor quality
Payahoo 2014 Low risk Low risk Low risk Low risk Unclear risk Low risk Unclear risk Fair quality
Foroozanfard2015 Low risk Low risk Low risk Low risk Low risk Low risk Low risk Good quality
Gunasekara 2011 Unclear risk Unclear risk Unclear risk Unclear risk Low risk Low risk Low risk Poor quality
Kim 2012 Unclear risk Unclear risk Unclear risk Unclear risk Unclear risk Low risk Low risk Poor quality
Islam 2016 Low risk Low risk Low risk Unclear risk Low risk Low risk Low risk Fair quality
Afkhami-Ardekani 2008 Unclear risk Unclear risk High risk High risk High risk High risk Unclear risk Poor quality
Partida-Hernández 2006 High risk Unclear risk Unclear risk Unclear risk Low risk Low risk Low risk Poor quality
Momen-Heravi 2017 Low risk Unclear risk Unclear risk High risk Low risk Low risk Unclear risk Poor quality
Al-Maroof 2006 Unclear risk Unclear risk Unclear risk Unclear risk High risk High risk Unclear risk Poor quality
Dias 2014 Unclear risk Low risk Low risk Low risk High risk Low risk Low risk Fair quality
Jamilian 2016 Low risk Low risk Low risk Low risk Low risk Low risk Low risk Good quality
Mahmoodianfard 2015 Unclear risk Unclear risk Unclear risk Unclear risk High risk Low risk Unclear risk Poor quality