| unlike persistent tiredness | 3 | other |
| often | 3 | degree |
| for a long time | 2 | temporal |
| cause → be → unknown | 33 |
| cause → be → unclear | 5 |
| cause → remain → unknown | 4 |
| negative | neutral | positive |
| 0.544 | 0.414 | 0.042 |
| Raw frequency | 42 |
| Normalized frequency | 1.000 |
| Modifier score | 0.650 |
| Perplexity | 48.497 |