Table 1 Hierarchy of evidence
Level | ES document (used for effect size estimation) | Included studies |
|---|---|---|
1 | A review of reviews of RCTs | Overview; umbrella review; meta-review; (systematic) review of (systematic) reviews |
2 | A systematic review of RCTs from Cochrane collaboration | Systematic review, meta-analysis and their combination |
3 | Other systematic review of RCTs | Systematic review, meta-analysis and their combination |
4 | RCTs in which case they were considered equally relevant ES documents from which we calculated the combined effect size | RCTs |
5 | Non-randomised controlled studies in cases were true randomisation was not feasible or ethical | Non-randomised controlled studies |