Table 2.
The methodological quality of the included studies.
| Author/Year | Methodological Quality Rating (EPHPP) | ||||||
|---|---|---|---|---|---|---|---|
| Selection Bias | Study Design | Confounders | Blinding | Data Collection Method | Withdrawals and Dropouts | Overall | |
| Kinnunen et al. 2007 | Moderate | Strong | Strong | Weak | Strong | Moderate | Moderate |
| Huang et al. 2011 | Moderate | Strong | Strong | Moderate | Strong | Moderate | Moderate |
| Ozdemir et al. 2015 | Moderate | Strong | Strong | Weak | Strong | Strong | Moderate |
| Garshasbi and Faghih Zadeh 2005 | Weak | Strong | Strong | Weak | Weak | Strong | Weak |
| Ronnberg et al. 2014 | Moderate | Strong | Strong | Weak | Strong | Strong | Moderate |
| Stafne et al. 2012 | Moderate | Strong | Strong | Weak | Strong | Strong | Moderate |
| Songoygard et al. 2012 | Moderate | Strong | Strong | Moderate | Strong | Strong | Strong |
| Gustafsson et al. 2016 | Moderate | Strong | Strong | Weak | Weak | Strong | Weak |
| Eggen et al. 2012 | Weak | Strong | Weak | Moderate | Strong | Moderate | Weak |
| Miquelutti et al. 2013 | Moderate | Strong | Strong | Weak | Strong | Moderate | Moderate |
| Sagedal et al. 2017 | Moderate | Strong | Strong | Moderate | Strong | Strong | Strong |
| Haakstad et al. 2018 | Moderate | Strong | Strong | Moderate | Strong | Moderate | Moderate |
| Montoya Arizabaleta et al. 2010 | Moderate | Strong | Strong | Moderate | Strong | Moderate | Moderate |
| Robledo-Colonia et al. 2012 | Moderate | Strong | Strong | Moderate | Strong | Strong | Strong |
| Marquez-Sterling et al. 2000 | Weak | Weak | Strong | Weak | Strong | Moderate | Weak |
| Suputtitada et al. 2002 | Weak | Weak | Strong | Weak | Strong | Moderate | Weak |
| Hui et al. 2006 | Weak | Weak | Strong | Weak | Weak | Moderate | Weak |
| Hui et al. 2012 | Strong | Strong | Strong | Weak | Strong | Moderate | Moderate |
| Haakstad and Bo 2011 | Weak | Strong | Strong | Moderate | Strong | Moderate | Moderate |
| Haakstad and Bo 2015 | Weak | Strong | Strong | Moderate | Weak | Moderate | Weak |
| Haakstad et al. 2016 | Weak | Strong | Strong | Moderate | Weak | Weak | Weak |
| Perales et al. 2015 | Moderate | Strong | Strong | Moderate | Strong | Strong | Strong |
| da Silva et al. 2017 | Moderate | Strong | Strong | Weak | Strong | Strong | Moderate |
| Kluge et al. 2011 | Weak | Strong | Weak | Weak | Strong | Strong | Weak |
| Gau et al. 2011 | Moderate | Strong | Strong | Weak | Strong | Weak | Weak |
| Aşcı and Rathfisch 2016 | Moderate | Strong | Strong | Strong | Strong | Strong | Strong |
| Ruiz et al. 2013 | Moderate | Strong | Strong | Weak | Strong | Strong | Moderate |
| Sklempe Kokic et al. 2017 | Weak | Strong | Strong | Moderate | Strong | Strong | Moderate |
| Ghodsi and Asltoghiri 2014 | Weak | Weak | Strong | Weak | Weak | Weak | Weak |
EPHPP: the Effective Public Health Practice Project.