| Source | Sequence generation | Allocation concealment | Blinding of participants | Incomplete outcome data | Selective outcome reporting | Other sources of bias |
| Batik et al., 2008 [19] | Unclear | Unclear | Unclear | No | Yes | No |
| Belalcazar et al., 2010 [20] | Unclear | Unclear | Unclear | Yes | Yes | Unclear |
| Christian et al., 2008 [21] | Unclear | Unclear | No | Yes | Yes | Unclear |
| De Greef et al., 2011 [22] | Yes | Yes | No | No | Yes | No |
| Debussche et al., 2012 [23] | Yes | Unclear | Unclear | Yes | Yes | Unclear |
| Di Loreto et al., 2003 [14] | Unclear | Unclear | Unclear | Yes | Yes | Unclear |
| Eakin et al., 2010 [24] | Unclear | Unclear | Unclear | Yes | Yes | Unclear |
| Eakin et al., 2009 [25] | Unclear | Unclear | Unclear | Yes | Yes | Unclear |
| Eakin et al., 2014 [26] | Yes | Unclear | Unclear | Yes | Yes | No |
| Eakin et al., 2013 [27] | Yes | Unclear | Unclear | Yes | Yes | No |
| Fowles et al., 2014 [28] | No | No | No | Yes | Yes | No |
| Fowles et al., 2014 [29] | No | No | No | Yes | Yes | No |
| Gregg et al., 2012 [30] | Unclear | Unclear | Unclear | Yes | Yes | Unclear |
| Kang et al., 2010 [31] | Unclear | Unclear | Unclear | Yes | Yes | No |
| Kirk et al., 2009 [32] | Yes | Yes | Yes | Yes | Yes | Unclear |
| Kirk et al., 2004 [33] | Yes | Yes | Unclear | Yes | Yes | Yes |
| Kirk et al., 2004 [34] | Yes | Yes | Unclear | Yes | Yes | Yes |
| Look ahead group, 2014 [35] | Unclear | Unclear | Unclear | Yes | Yes | Yes |
| Plotnikoff et al., 2013 [36] | Yes | Yes | Unclear | Yes | Yes | Unclear |
| Plotnikoff et al., 2011 [37] | Yes | Unclear | Unclear | Yes | Yes | Unclear |
| Plotnikoff et al., 2010 [38] | Unclear | Unclear | Unclear | Yes | Yes | No |
| Wadden et al., 2009 [39] | Unclear | Unclear | Unclear | Yes | Yes | Yes |
| Yoo et al., 2007 [40] | Unclear | Unclear | Unclear | Yes | Yes | No |
| % Yes | 39.1 | 21.7 | 4.3 | 91.3 | 100 | 17.4 |
| % No | 8.7 | 8.7 | 17.4 | 8.7 | - | 39.1 |
| % Unclear | 52.2 | 69.6 | 78.3 | - | - | 43.5 |