| Study | Bias | 
| Randomisation process | Deviations from intended interventions | Missing outcome data | Measurement of the outcome | Selection of the reported results | Overall | 
| Authors' judgement | Support for judgement | Authors' judgement | Support for judgement | Authors' judgement | Support for judgement | Authors' judgement | Support for judgement | Authors' judgement | Support for judgement | Authors' judgement | Support for judgement | 
| Falsaperla 2019 | Some concerns | No information on allocation concealment, but baseline characteristics do not show any differences between the two groups | Low risk of bias | Single blinded study with the personnel aware of the intervention allocation, but there seems to be no deviations that arouse outside the trial context. Also all patients analysed as randomised. | Low risk of bias | Data reasonably complete for all the included patients | Low risk of bias | Being an objective outcome, it is unlikely that assessment of the outcome would be influenced by knowledge of allocation group | Some concerns | A trial protocol is not available for assessment | High risk of bias | Some concerns in more than one domain | 
| Khan 2020 | Some concerns | No information on allocation concealment, but baseline characteristics do not show any differences between the two groups. | Low risk of bias | Though the personnel were aware of the intervention allocation, but there seems to be no deviations that arouse outside the trial context. Also all patients analysed as randomised. | Low risk of bias | Data reasonably complete for all the included patients | Low risk of bias | Being an objective outcome, it is unlikely that assessment of the outcome would be influenced by knowledge of allocation group | Some concerns | A trial protocol is not available for assessment | High risk of bias | Some concerns in more than one domain |