Risk of bias in non-randomised studies (ROBINS-I tool)
| Morris-Stiff et al 35 | |
| Bias due to confounding | + |
| Bias in selection of participants into the study | − |
| Bias in classification of interventions | + |
| Bias due to deviations from intended interventions | + |
| Bias due to missing data | + |
| Bias in measurement of outcomes | + |
| Bias in selection of the reported result | + |
| Overall bias | Serious risk |