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Research methodology description and associated level of evidence
| Level of evidence | Description |
|---|---|
| Ia | Meta-analysis of randomized control trials |
| Ib | At least one randomized control trial |
| IIa | At least one well-designed study without randomization |
| IIb | At least one well-designed quasi-experimental study |
| III | At least one well-designed non-experimental descriptive study |
| IV | Expert committee reports, opinions and/or experience |
