Quality assessment ratings of included studies
| Study | Selection bias | Study design | Confounders | Blinding | Data collection method | Withdrawals and dropouts | Global rating |
|---|---|---|---|---|---|---|---|
| Bollegala et al (2013)29 | Weak | Moderate | Weak | Moderate | Strong | Weak | Weak |
| Dabadie et al (2008)33 | Moderate | Weak | Weak | Moderate | Weak | Weak | Weak |
| Hait et al (2008)28 | Weak | Weak | Weak | Moderate | Weak | Weak | Weak |
| Sebastian et al (2012)34 | Weak | Weak | Strong | Moderate | Weak | Weak | Weak |
| Wright et al (2014)35 | Weak | Weak | Weak | Moderate | Weak | Weak | Weak |
| Goodhand et al (2010)16 | Moderate | Moderate | Strong | Moderate | Strong | Weak | Moderate |