| Relationship between surgery and incidents | Cases (n = 236) | % |
| Surgery-related incidents | 128 | 54.2 |
| Intraoperative management | 75 | 31.8 |
| Postoperative management | 51 | 21.6 |
| Others | 2 | 1.6 |
| Non-surgery-related incidents | 108 | 45.8 |
| Postoperative management | 20 | 8.5 |
| Others | 88 | 81.5 |