Risk of bias assessment, using ROBINS-I tool
| Study | Confounding | Selection of participants into the study | Classification of interventions | Deviations from intended interventions | Missing data | Measurement of outcome | Selection of the reported result | Overall |
| Abernathy III et al 22 | M | L | L | L | NI | L | S | S |
| Gabbe et al 23 | S | L | L | L | M | L | S | S |
| Kim J et al 2019 | S | L | S | L | NI | S | S | S |
| Kelly et al 24 | S | L | L | L | M | L | S | S |
| Kim M et al 26 | S | L | L | L | NI | L | S | S |
| Metcalfe et al 27 | S | L | S | L | L | L | S | S |
| Vasse et al 28 | S | L | L | L | L | L | M | S |
C, critical risk; L, low risk; M, moderate risk; NI, no information; S, severe risk.