Floor and ceiling effects of the Dutch PBC-40 and PBC-27
| Domains (number of items) | Possible range | Actual range | n | Floor (%) | Ceiling (%) |
| PBC-40 | |||||
| Symptoms (7) | 7–35 | 7–32 | 176 | 1.7 | 0.0 |
| Itch (3) | 3–15 | 3–13 | 109 | 27.0 | 0.0 |
| Fatigue (11) | 11–55 | 11–53 | 177 | 1.7 | 0.0 |
| Cognition (6) | 6–30 | 6–30 | 176 | 19.3 | 0.6 |
| Social (10) | 10–50 | 10–49 | 176 | 5.1 | 0.0 |
| Emotional (3) | 3–15 | 3–15 | 176 | 10.8 | 1.7 |
| PBC-27 | |||||
| Symptoms (3) | 3–15 | 3–15 | 177 | 11.9 | 0.6 |
| Dryness (2) | 2–10 | 2–10 | 177 | 6.8 | 7.3 |
| Itch (3) | 3–15 | 3–13 | 109 | 27.0 | 0.0 |
| Fatigue (8) | 8–40 | 8–38 | 177 | 2.8 | 0.0 |
| Cognition (5) | 5–25 | 5–25 | 176 | 19.3 | 0.6 |
| Social (3) | 3–15 | 3–15 | 176 | 25.0 | 2.3 |
| Emotional (3) | 3–15 | 3–15 | 176 | 10.8 | 1.1 |