Table 2 Risk of bias of included studies
Author | Year | Bias domain | ||||||
|---|---|---|---|---|---|---|---|---|
Bias due to confounding | Bias in selection of participants into the study | Bias in classification of exposure | Bias due to missing data | Bias in measurement of outcomes | Bias in selection of the reported result | Overall | ||
Alwasel | 2011 | Low/Moderate | Low | Serious | Low | Low | Low | Moderate |
Arab | 2001 | Low | Low | Low | Serious | Low | Low | Moderate |
Awwad | 2012 | Moderate | Low | Low | Low | Low | Low | Low |
Azizi | 2014 | Low | Low | Low | Moderate | Low | Low | Low |
Bayoglu Tekin | 2016 | Low | Low | Low | Low | Low | Low | Low |
Daley | 2018 | Moderate | Low | Moderate | Moderate | Low | Low | Moderate |
Hefni | 1993 | Low/Moderate | Low | Low | Low | Low | Low/Moderate | Low |
Hizli | 2012 | Low | Low | Low | Low | Low | Low | Low |
Karateke | 2016 | Moderate | Low | Low | Low | Low | Low | Low |
Kavehmanesh | 2004 | Low/Moderate | Low | Low | Low | Low/Moderate | Low | Low |
Malhotra | 1989 | Moderate | Low | Low | Low/Moderate | Low | Low | Moderate |
Makvandi | 2013 | Moderate | Low | Low | Low | Low | Low | Low |
Naderi | 2004 | Moderate | Low | Low | Low | Low | Low | Low |
Ozturk | 2011 | Moderate | Low | Low | Low | Low/Moderate | Low | Low |
Petherick | 2014 | Moderate/Serious | Low | Moderate | Low | Low | Low | Moderate |
Rezk | 2016 | Low | Low | Low | Low | Low | Low | Low |
Sakar | 2016 | Low | Low | Low | Low | Low | Low | Low |
Sarafraz | 2013 | Low | Low | Low | Low | Low | Low | Low |
Savitri | 2018 | Low | Serious | Low | Low | Low | Low | Moderate |
Seckin | 2014 | Low | Low | Low | Low | Low | Low | Low |
Shahgheibi | 2005 | Low/Moderate | Low | Low | Low | Low | Low | Low |
Ziaee | 2010 | Low | Low | Low | Low | Low | Low | Low |