The level of evidence based on study design10
| Level of evidence | |
|---|---|
| I-A | Meta-analysis of randomised controlled trials |
| I-B | Randomised controlled trial |
| II-A | Controlled study without randomisation |
| II-B | Quasiexperimental study |
| III | Descriptive study (comparative, correlation, case-control) |
| IV | Expert committee report/opinion and/or clinical opinion of respected authority |