Classes of recommendations
| Definition | Wording to use | |
| Class I | Evidence and/or general agreement that a given treatment or procedure is beneficial, useful, effective | Is recommended or is indicated |
| Class II | Conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of the treatment or procedure | |
| Class IIa | Weight of evidence/opinion is in favour of usefulness/efficacy | Should be considered |
| Class IIb | Usefulness/efficacy is less well established by evidence/opinion | May be considered |
| Class III | Evidence or general agreement that the given treatment or procedure is not useful/effective, and in some cases may be harmful | Is not recommended |