Risk of Bias Assessment of Randomised Controlled Trials (ROB-2)
| Study | Domain 1 | Domain 2 | Domain 3 | Domain 4 | Domain 5 | Overall risk of bias | |
| Risk of bias arising from the randomisation process | Risk of bias due to deviations from the intended interventions (effect of assignment to intervention) | Risk of bias due to deviations from the intended interventions (effect of adhering to intervention) | Missing outcome data | Risk of bias in measurement of the outcome | Risk of bias in selection of the reported result | ||
| Manz et al18 | Low | Low (unblinded participants) | Low | Low | Low | Low | Low |
| Manz et al19 | Low | Low (unblinded participants) | Low | High risk (missing data for secondary outcome) | Low | Low | High risk (unpredictable) |
| Hassoon et al20 | Low | Low (unblinded participants) | Low | Low | Low | Low | Low |
| Strömblad et al21 | Low | Some concerns (Hawthorne’s effect and unequal arm size after exclusion postrandomisation) | Low | Low | Low | Low | Some concerns (unpredictable) |
| Seok et al31 | Low | Low (unblinded participants) | Low | Low | Low | Low | Low |
| Nicolae et al29 | Low | Low | Low | Low | Low | Low | Low |
| Nelson et al26 | Low | High risk (per-protocol analysis with 13% dropout rate) | Low | High risk (13% missing outcome data) | Low | Low | High risk (unpredictable) |
The risk of bias for each domain of the study is colour-coded. High risk of bias: red; moderate risk of bias: orange and low risk of bias: green.