TABLE 6.
Cochrane risk of bias.
| Study (year) | Domain 1a: risk of bias arising from the randomization process | Domain S: risk of bias arising from period and carryover effects | Domain 2: risk of bias due to deviations from the intended interventions (effect of assignment to intervention) | Domain 3: risk of bias due to missing outcome data | Domain 4: risk of bias in the measurement of the outcome | Domain 5: risk of bias in the selection of the reported result | Overall risk of bias1 |
|---|---|---|---|---|---|---|---|
| Crossover RCTs | |||||||
| van Faassen et al. (1987) [85] | Some concerns | Low | Low | Low | Low | Some concerns | Some concerns |
| Windey et al. (2012) [73] | Low | High | Some concerns | Low | Low | Some concerns | High |
| Foerster et al. (2014) [86] | Low | Some concerns | Low | Low | Low | Some concerns | Some concerns |
| Lang et al. (2018) [87] | Some concerns | Some concerns | Some concerns | Low | Low | Some concerns | Some concerns |
| Hess et al. (2018) [84] | Some concerns | Some concerns | Some concerns | Low | Low | Some concerns | Some concerns |
| Schmedes et al. (2019) [71] | Low | Low | Some concerns | Low | Low | Some concerns | Some concerns |
| Pagliai et al. (2020) [74] | Low | High | Some concerns | Low | Low | Some concerns | High |
| Crimarco et al. (2020) [88] | Low | Low | Low | Low | Low | Some concerns | Some concerns |
| Parallel RCTs | |||||||
| Kahleova et al. (2020) [89] | Low | N/A | Low | Low | Low | Some concerns | Some concerns |
| Meslier et al. (2020) [92] | Low | N/A | Low | Low | Low | Some concerns | Some concerns |
| Kohnert et al. (2021) [91] | Low | N/A | Low | Low | Low | Some concerns | Some concerns |
| McKenna et al. (2021) [90] | Low | N/A | Low | Low | Low | Some concerns | Some concerns |
| Bratlie et al. (2020) [93] | Low | N/A | Some concerns | Low | Low | Some concerns | Some concerns |
1
For the description of overall risk of bias, “some concerns” refers to “the study is judged to raise some concerns in ≥1 domain for this result but not to be at high risk of bias for any domain”; “high” refers to “the study is judged to have some concerns for multiple domains in a way that substantially lowers confidence in the result.” N/A, not applicable; RCT, randomized controlled trial.