Risk of bias summary for non-RCTs (ROBINS-I)
| Preintervention | At intervention | Postintervention | ||||||
| Studies | 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 risk of bias |
| Arraras 2008a16 | M | M | M | M | M | M | Unclear | Low or moderate risk if bias for all domains |
| Browall 200817 | M | M | M | S | M | M | Unclear | Serious risk of bias in at least one domain |
| Dees 200019 | S | S | L | M | M | M | Unclear | Serious risk of bias in at least one domain |
| Hurria 200620 | M | M | L | M | L | M | Unclear | Low or moderate risk if bias for all domains |
| Watters 200322 | S | M | L | M | L | M | Unclear | Serious risk of bias in at least one domain |
| Gállego Pérez-Larraya 201124 | M | M | L | M | S | S | Unclear | Serious risk of bias in at least one domain |
| Minniti 200926 | M | M | L | M | L | M | Unclear | Low or moderate risk if bias for all domains |
| Minniti 201327 | M | M | L | M | S | M | Unclear | Serious risk of bias in at least one domain |
| Mohile 201128 | S | M | M | Unclear | L | M | Unclear | Serious risk of bias in at least one domain |
| Arraras 2008b29 | M | S | Unclear | Unclear | M | M | Unclear | Serious risk of bias in at least one domain |
| Bouvier 200830 | S | M | Unclear | Unclear | L | M | Unclear | Serious risk of bias in at least one domain |
| Chang 201231 | M | M | L | M | M | M | Unclear | Low or moderate risk if bias for all domains |
| Caffo 200332 | S | S | L | Unclear | M | M | Unclear | Serious risk of bias in at least one domain |
| Park 201333 | M | M | M | M | M | M | Unclear | Low or moderate risk if bias for all domains |
C, critical risk; L, low risk; M, moderate risk; S, serious risk.