Grading of recommendations19
| Grade | Recommendation (based on AHCPR 1994) |
|---|---|
| A (evidence levels Ia, Ib) | Requires at least one randomised, controlled trial as part of the body of literature of overall good quality and consistency addressing the specific recommendation |
| B (evidence levels IIa, IIb, III) | Requires availability of well conducted clinical studies but no randomised clinical trials on the topic of recommendation |
| C (evidence level IV) | Requires evidence from expert committee reports or opinions and/or clinical experience of respected authorities. Indicates absence of directly applicable studies of good quality |