Table 4.
Risk of bias assessment using Public Health Ontario’s meta-tool for quality assessment [25]
| Item | Criteria | Backer 2001 [34] | Boehmer 2011 [35] | Klompas 2008 [36] | Matin 2006 [40] | Overhage 2008 [39] | Roels 1998 [37] | Sickbert-Bennett 2011 [41] | Simmons 2002 [38] |
|---|---|---|---|---|---|---|---|---|---|
| Relevancy | Topic(s) relevant | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Validity | Presented objectively | Unclear | Unclear | Unclear | Unclear | Yes | Yes | Yes | Yes |
| Conclusions justified | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | |
| Reliability | Clear methods | Yes | Yes | Yes | Yes | Unclear | Unclear | Yes | Unclear |
| Appropriate methods | Unclear | Yes | Yes | Yes | Unclear | Unclear | Yes | Yes | |
| Free from bias | No | Yes | Unclear | No | Unclear | Unclear | No | Unclear | |
| Ethics described | Unclear | Unclear | Unclear | Unclear | No | Unclear | Yes | Yes | |
| Confident in findings | Unclear | Yes | Unclear | Unclear | No | No | Unclear | No | |
| Applicability | Applicable | Unclear | Yes | Yes | Unclear | Unclear | Yes | Yes | Yes |
| Overall Risk | High | Low | Moderate | Moderate | High | Moderate | Low | Moderate | |