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 of level 3 or four or Extrapolated evidence from studies rates 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 Good Practice Points |