| back through exit openings | 12 | other |
| from the tissue | 10 | other |
| from the catheter | 10 | other |
| needle → be → retracted | 185 |
| needle → be in → retracted position | 9 |
| needle → be retracted after → use | 5 |
| negative | neutral | positive |
| 0.131 | 0.821 | 0.048 |
| Raw frequency | 199 |
| Normalized frequency | 0.649 |
| Modifier score | 0.500 |
| Perplexity | 419.004 |