Table 3 Risk of bias summary showing the review authors’ judgements about each methodological quality item for each included study
Selection bias | Performance bias | Detection bias | Attrition bias | Reporting bias | Other bias | Total | ||
|---|---|---|---|---|---|---|---|---|
Author (year) In chronological order | Random sequence generation | Allocation concealment | Blinding of participants and personnel | Blinding of outcome assessment | Incomplete outcome data | Selective reporting | Other (eg. sample size) | No. of low risk of bias (✓) |
Morrison et al. 1988 | ? | ? | ? | X | ? | ? | ? | 0 |
Ferrell et al. 1997 | ? | ? | ? | ✓ | ✓ | ? | x | 2 |
Linton et al. 1997 | ✓ | ✓ | ? | ? | ✓ | ? | ? | 3 |
Soares et al. 2002 | x | x | ✓ | ✓ | ✓ | ? | x | 3 |
Moseley et al. 2004 | ✓ | ✓ | ✓ | ✓ | ✓ | ? | ? | 5 |
Ruehlman et al. 2012 | ? | ? | ✓ | ✓ | ✓ | ? | ✓ | 4 |
Sparkes et al. 2012 | ✓ | ? | ✓ | ✓ | ✓ | ? | ? | 4 |
Gallagher et al. 2013 | ✓ | ✓ | ✓ | ✓ | ✓ | ? | ✓ | 6 |
Van Oosterwijck et al. 2013 | ✓ | ✓ | ✓ | ✓ | ✓ | ? | X | 5 |
No. of studies with low risk of bias - ✓ | 5 | 4 | 6 | 7 | 8 | 0 | 2 | |
No. of studies with uncertain/unclear - ? | 3 | 4 | 3 | 1 | 1 | 9 | 4 | |
No. of studies with high risk of bias—X | 1 | 1 | 0 | 1 | 0 | 0 | 3 | |