Grading of recommendations
| Grade | Type of recommendations |
|---|---|
| A (levels Ia, Ib) | Requires at least one randomised controlled trial as part of a body of literature of overall good quality and consistency addressing the specific recommendation |
| B (levels IIa, IIb, III) | Requires availability of well conducted clinical studies but no randomised clinical trials on the topic of recommendation |
| C (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 |