Table S3.
Risk of bias assessment of each included studya
| Study validity domains | Sequence generation | Allocation concealment | Blinding of participants and personnel | Blinding of outcome assessment | Incomplete outcome data | Selective outcome reporting | Other sources of bias |
|---|---|---|---|---|---|---|---|
| Probiotics | |||||||
| Ball et al,1 1990 | Unclear | Unclear | Low | Low | Low | Unclear | Low |
| Kamada et al,2 1993 | Low | Low | Low | Low | Low | Unclear | Unclear |
| Fonseca-Aten et al,3 2006 | Unclear | Unclear | Unclear | Unclear | High | Low | Unclear |
| Piacentini et al,4 2007 | Low | Unclear | Low | Low | Unclear | Low | Unclear |
| Tahan et al,5 2007 | Low | Unclear | Low | Low | Low | Low | Unclear |
| Rasul et al,6 2008 | Low | Low | Low | Low | High | Low | Unclear |
| Strunk et al,7 2008 | Unclear | Unclear | Unclear | Unclear | Low | Low | Unclear |
| Kabir et al,8 2009 | Low | Unclear | Unclear | Unclear | Low | Low | Unclear |
| Koutsoubari et al,9 2012 | Low | High | High | High | Low | Low | Unclear |
| Pinto et al,10 2012 | Low | Unclear | Unclear | Unclear | Low | Low | Unclear |
| Mccallum et al,11 2013 | Low | Low | Low | Low | Low | Low | Unclear |
| Chiong-Manaysay and Andaya,12 2014 | Unclear | Unclear | Unclear | Unclear | Unclear | Unclear | Unclear |
| Bacharier et al,13 2015 | Low | Low | Low | Low | Low | Low | Unclear |
| Beigelman et al, 14 2015 (letter) | Low | Low | Low | Low | Low | Low | Unclear |
| Beigelman et al,15 2015 | Low | Low | Low | Low | Low | Low | Low |
| Mccallum et al,16 2015 | Low | Low | Low | Low | Low | Low | Low |
| Silveira D’Azevedo et al,17 2016 | Unclear | Unclear | Unclear | Unclear | Unclear | Unclear | Unclear |
| Stokholm et al,18 2016 | Low | Low | Low | Unclear | Low | Low | Low |
| Wan et al,19 2016 | Low | Low | Unclear | Unclear | Low | Low | Unclear |
| Zhou et al,20 2016 | Unclear | Unclear | Low | Low | Low | Low | Low |
| Mandhane et al,21 2017 | Low | Low | Low | Low | Unclear | Low | Low |
| Pinto et al,22 2017 | Unclear | Unclear | Unclear | Unclear | Unclear | Unclear | Unclear |
Notes:
a
Each domain has been evaluated as being “High”, “Low”, or “Unclear” regarding the risk of bias following the guidelines of Cochrane. Collaboration’s tool for assessing risk of bias, the thorough and original evaluation form is attached in the following pages. “Low” in all Domains would place a study at “Low Risk of Bias”; “High” in any of the Domains would place a study at “High Risk of Bias”; “Unclear” in any of the domains would place the study at “Unclear Risk of Bias”.