RF stage | Description | GFR |
G1 | Up and optimal | >105 90 - 104 |
G2 | Medium | 75 - 89 60 - 74 |
G3a | Medium to moderate | 45 - 59 |
G3b | Moderate to severe | 30 - 44 |
G4 | Severe | 15 - 29 |
G5 | ERF | <15 |