Table 4

 Precision of the PBC-40

Domain (No of questions)Possible rangeActual rangeMean scoreSDFloor effect (%)Ceiling effect (%)
Estimates of floor and ceiling effects (numbers of respondents with the minimum possible and maximum possible scores for each domain, respectively).
Fatigue (11)11−5511−5434.69.51.30.0
Social (10)10−5011−4928.59.20.00.0
Symptoms (7)7−357−3118.55.052.50.0
Cognitive (6)6−306−3015.76.1512.52.9
Emotion (3)3−153−159.083.22.05.4
Itch (3)3−153−156.023.3236.71.7