Levels of Evidence, Levels of Recommendation
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1. Levels of Evidence
| Type | |
|---|---|
| 1a | At least one systematic review based on methodologically sound randomized controlled trials (RCTs) |
| 1b | At least one sufficiently large, methodologically sound RCT |
| 2a | At least one high-quality non-randomized study, e.g., a cohort study |
| 2b | At least one high-quality study of another type of quasi-experimental study |
| 3 | At least one methodologically sound non-experimental study |
| 4 | Opinions and beliefs of respected authorities based on clinical experience, expert committees, and descriptive studies. This also includes prescribing information, FDA labels, guidelines, textbooks, and narrative reviews. |
Source:
DOI: 10.1055/s-0030-1255425
2. Levels of Recommendation
| Level | ’s Recommendation |
|---|---|
| A high- | , high-quality body of literature that includes at least one randomized trial with evidence levels Ia or Ib |
| B | A body of evidence comprising well-conducted, non-randomized clinical trials with evidence levels IIa, IIb, or III |
| C | The evidence base includes reports and opinions from experts or clinical experiences from recognized authorities, which are classified as Level IV evidence. However, there is a lack of directly applicable, high-quality clinical studies. |
Source:
DOI: 10.1055/s-0030-1255425