| Stage | GFR ml/min/1.73m2 | Absolute frequency | Prevalence |
| V | <15 | 1 | 0.6% |
| IV | [15 - 30] | 8 | |
| III | [31 - 60] | 172 | 12.1% |
| II | [61 - 90] | 747 | 52.8% |
| I | >90 | 488 | 34.5% |