| Level | Description |
|---|---|
| 1a (strong) | Well-designed meta-analysis, or 2 or more “high-quality” RCT's (PEDro score ≥ 6) showing similar findings. |
| 1b (moderate) | 1 RCT of “high-quality” (PEDro score ≥ 6). |
| 2a (limited) | At least 1 “fair-quality” RCT (PEDro score = 4–5). |
| 2b (limited) | At least 1 “poor-quality” RCT (PEDro score < 4) or well-designed nonexperimental study (nonrandomized controlled trial, quasi-experimental studies, cohort studies with multiple baselines, single subject series with multiple baselines, etc.). |
| 3 (consensus) | Agreement by an expert panel or a group of professionals in the field or a number of pre–post studies, all with similar results. |
| 4 (conflict) | Conflicting evidence of 2 or more equally well-designed studies. |
| 5 (no evidence) | No well-designed studies—only case studies/case descriptions, or cohort studies/single-subject series with no multiple baselines. |
PEDro = Physiotherapy Evidence Database; RCT = randomized controlled trial
From: Methods
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