Table 4 Assessment of risk of bias.
S.no | Risk of bias criteria assessed | Harris et al., 2013 [31] | Hegarty et al., 2016 [32] | Harris et al., 2017 [30] | Coors et al., 2018 [29] | Harding et al., 2021 [23] |
|---|---|---|---|---|---|---|
1 | Random sequence generation | Low | Low | Low | High | Low |
2 | Allocation concealment | Low | Low | Unclear | Unclear | Low |
3 | Blinding of participants and personnel | Low | Low | Unclear | Unclear | Low |
4 | Blinding of outcome assessment | Low | Low | Unclear | Unclear | Low |
5 | Incomplete outcome data | Low | Low | Low | Low | Low |
6 | Selective reporting | Low | Low | Low | Low | Low |
7 | Is it clear in the study what is the ‘cause’ and what is the ‘effect’ (i.e., there is no confusion about which variable comes first)? | Low | Low | Low | Low | Low |
8 | Were the participants included in any comparisons similar? | Low | Low | Low | Low | Low |
9 | Were the participants included in any comparisons receiving similar treatment/ care, other than the exposure or intervention of interest? | Low | Low | Low | Low | Low |
10 | Was there a control group? | Low | Low | Low | Low | Low |
11 | Were there multiple measurements of the outcome both pre and post the intervention/ exposure? | Low | Unclear | Unclear | Unclear | Unclear |
12 | Was follow up complete and if not, were differences between groups in terms of their follow up adequately described and analyzed? | Low | Low | Low | Low | Low |
13 | Were the outcomes of participants included in any comparisons measured in the same way? | Low | Low | Low | Low | Low |
14 | Were outcomes measured in a reliable way? | Low | Low | Low | Low | Low |
15 | Was appropriate statistical analysis used? | Low | Low | Low | Low | Low |
