Table 3.
Risk of bias of included studies
| Study (year) | Was the allocation sequence adequately generated? | Was allocation adequately concealed? | Was the study adequately protected against contamination? | Was knowledge of the allocated interventions adequately prevented? | Were incomplete outcome data adequately addressed? | Was baseline outcome measurement similar? | Was baseline characteristics similar? | Was the study free from selective outcome reporting? | Overall riska |
|---|---|---|---|---|---|---|---|---|---|
| 1. Basheti (2009) | Low | Unclear | Unclear | Unclear | Low | Low | Low | Low | Unclear |
| 2. Chalker (2005) | Unclear | Unclear | Low | Unclear | Low | Low | Unclear | Low | Unclear |
| 3. Chuc (2002) | Low | Unclear | Low | Low | Low | Low | Unclear | Low | Unclear |
| 4. de Almeida Neto (2000) | Unclear | Unclear | Unclear | Unclear | Low | Unclear | Unclear | Low | Unclear |
| 5. de Almeida Neto (2000) | Unclear | Unclear | Unclear | Unclear | Low | Unclear | Unclear | Low | Unclear |
| 6. Dolovich (2007) | Low | Unclear | Unclear | Low | Low | Unclear | Low | Low | Unclear |
| 7. Garcia (1998) | Unclear | Unclear | Low | Low | Low | Unclear | Unclear | Low | Unclear |
| 8. Garcia (2003) | Low | Unclear | Low | Low | Low | Unclear | Unclear | Low | Unclear |
| 9. Kimberlin (1993) | Unclear | Low | Unclear | Unclear | Low | Unclear | Low | Low | Unclear |
| 10. Lalonde (2008) | Low | Low | Low | High | Low | Low | High | Low | High |
| 11. Mayer (1998) | Unclear | Unclear | Low | Low | Low | Low | Unclear | Low | Unclear |
| 12. Patwardhan (2012) | Low | Low | Low | Unclear | Low | Low | Low | Low | Unclear |
| 13. Prokhorov (2010) | Unclear | Unclear | Low | Unclear | Low | Unclear | Low | Low | Unclear |
| 14. Reeves (2007) | Low | Unclear | Low | High | Low | Unclear | Low | Low | High |
| 15. Sigrist (2002) | Unclear | Unclear | Unclear | Low | Low | Low | Unclear | Low | High |
| 16. Sinclair (1998) | High | Unclear | Low | Low | Low | Unclear | Low | Low | Unclear |
| 17. Watson (2002) | Low | Unclear | Low | Unclear | Low | Low | Low | Low | Unclear |
aKey for overall assessment of bias within a study; if low of bias for all key domains (low of bias); if unclear risk of bias for one or more key domains (unclear risk of bias); if high of bias for one or more key domains (high of bias)