| every 3–4 months | 2 | temporal |
| readily | 2 | manner |
| frequently | 2 | temporal |
| stent → be → replaced | 10 |
| stent → be → changed | 6 |
| stent → be → re | 5 |
| negative | neutral | positive |
| 0.310 | 0.611 | 0.079 |
| Raw frequency | 21 |
| Normalized frequency | 0.402 |
| Modifier score | 0.800 |
| Perplexity | 111.408 |