Categories of evidence and recommendations
| Evidence categories |
|---|
| (I) Based on well designed randomised controlled trials, meta-analyses, or systematic reviews |
| (II) Based on well designed cohort or case-control studies |
| (III) Based on uncontrolled studies or consensus |
| Strength of recommendation categories |
| (A) Directly based on category I evidence |
| (B) Directly based on category II evidence or extrapolated from category I evidence |
| (C) Directly based on category III evidence or extrapolated from category I or II evidence |