**A** | **Criteria for determining the certainty of evidence** |

High | Very confident that the true effect lies close to that of the estimate of the effect. |

Moderate | Moderately confident in the effect estimate. The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. |

Low | Confidence in the effect estimate is limited. The true effect may be substantially different from the estimate of the effect. |

Very low | Very little confidence in the effect estimate. The true effect is likely to be substantially different from the estimate of effect. |

**B** | **Interpretation of the strength of recommendation** |

Strong recommendation | Strong recommendations communicate the message that the guideline is based on the confidence that the desirable effects of adherence to the recommendation outweigh the undesirable consequences. |

Conditional recommendations | Conditional recommendations are made when there is less certainty about the balance between the benefits and harms or disadvantages of implementing a recommendation, or if the recommendations might not be applicable to all the population group. |