Table 1.
Summary of risk of bias assessment.
| Articles | Bias | Within Studies Risk of Bias | ||||
|---|---|---|---|---|---|---|
| Selection | Performance | Attrition | Detection | Reporting | ||
| Roberto et al., 2007 [48] | + | + | + | + | + | Low risk of bias |
| Morales et al., 2015 [49] | + | − | + | + | + | Low risk of bias |
| Tortolero et al., 2010 [50] | + | − | + | + | + | Low risk of bias |
| Cornelius et al., 2013 [51] | + | − | + | + | + | Low risk of bias |
| Aronson et al., 2013 [52] | − | − | + | + | + | Moderate risk of bias |
| Calloway et al., 2013 [53] | − | − | + | + | + | Moderate risk of bias |
| Espada et al., 2012 [54] | + | − | + | + | − | Moderate risk of bias |
| Gaydos et al., 2008 [55] | + | − | + | − | + | Moderate risk of bias |
| Lemieux et al., 2008 [56] | + | − | + | − | + | Moderate risk of bias |
| Hlavinkova et al., 2014 [57] | − | − | + | + | + | Moderate risk of bias |
| Gold et al., 2010 [58] | + | − | + | − | + | Moderate risk of bias |
| Stanton et al., 2015 [59] | + | − | + | + | − | Moderate risk of bias |
| Ateka et al., 2007 [60] | + | − | − | − | + | High risk of bias |
| O’Grady et al., 2009 [61] | + | − | − | − | + | High risk of bias |
| Peskin et al., 2015 [62] | + | − | + | − | − | High risk of bias |
| Mahat et al., 2008 [63] | − | − | − | + | + | High risk of bias |
For each bias: (+) = low risk and (−) = high risk or unclear risk. For within studies risk of bias: Low risk of bias = (+) for four or all types of bias. Moderate risk of bias = (+) for three types of bias. High risk of bias = for three or more types of bias.