| Grade | Pre its [number of patients] | Post its [number of patients] |
| 0 | 0 | 148 |
| 1 | 106 | 0 |
| 2 | 22 | 0 |
| 3 | 19 | 1 |
| 4 | 1 | 2 |
| 5 | 3 | 0 |
| 6 | 0 | 0 |