Grades of recommendations
| Grade | Type of evidence |
| A | At least one meta-analysis, systematic review or RCT rated as 1++ and directly applicable to the target population or |
| A systematic review of RCTs or a body of evidence consisting principally of studies rated as 1+ directly applicable to the target population and demonstrating overall consistency of results. | |
| B | A body of evidence including studies rated as 2++ directly applicable to the target population and demonstrating overall consistency of results or |
| Extrapolated evidence from studies rated as 1++ or 1+. | |
| C | A body of evidence including studies rated as 2+ directly applicable to the target population and demonstrating overall consistency of results or |
| Extrapolated evidence from studies rated as 2++. | |
| D | Evidence level 3 or 4 or. |
| Extrapolated evidence from studies rated as 2+. | |
| ✔ | Important practical points for which there is no research evidence, nor is there likely to be any research evidence. The guideline committee wishes to emphasise these as good practice points. |
RCT, randomised controlled trial.