Table 5.

Sensitivity to change and clinical significance of the improvement of the Perform Questionnaire Score

	Physical limitations	Activities of daily living	Beliefs and attitudes	Global score
Sensitivity to improvementa (N = 208)
Mean score (SD), visit 1	11.7 (4.6)	11.8 (3.7)	11.5 (4.4)	35.3 (11.7)
95% CI	11.1–12.4	11.3–12.3	10.8–12.1	33.5–37.1
Mean score (SD), visit 2	13.9 (4.1)	13.9 (3.4)	13.6 (4.1)	41.4 (10.7)
95% CI	13.3–14.5	13.4–14.3	13.0–14.2	39.8–43.0
Effect size	0.5	0.6	0.5	0.5
SRM	0.49	0.50	0.55	0.57
Sensitivity to deteriorationb (N = 84)
Mean score (SD), visit 1	11.6 (4.6)	12.2 (3.9)	11.4 (4.4)	35.6 (11.7)
95% CI	10.6–12.6	11.3–13.0	10.4–12.5	32.7–38.4
Mean score (SD), visit 2	8 (3.7)	8.6 (3.3)	8.1 (3.6)	25.1 (10)
95% CI	7.1–8.8	7.9–9.4	7.3–9.0	22.7–27.6
Effect size	−0.9	−1	−0.8	−1
SRM	−0.73	−0.83	−0.73	−0.76
Clinical significance (N = 288)
Mean change (SD) among stable patientsc	0.22 (4.97)	0.40 (4.61)	0.10 (4.45)	0.03 (12.69)
Mean change (SD) among improved patientsd	1.43 (4.74)	1.15 (4.23)	1.30 (4.31)	3.72 (10.22)
Minimally important difference (MID)e	1.21	0.75	1.2	3.69

Overall score ranges from 12 to 60, with low scores indicating worse patient perception of cancer-related fatigue. Dimension scores range from 4 to 20, with low scores indicating worse patient perception of cancer-related fatigue

SD standard deviation, SRM standardised response mean, CI confidence interval

^aAmong those patients who reported an improvement in the “health status transition item”

^bAmong those patients who reported a deterioration in the “health status transition item”

^cPatients who experienced a change in Hb < 1 g/dL to a lower limit of −1 g/dL

^dPatients who experienced an increase in Hb ≥ 1 g/dL

^eThe difference between the mean change of stable patients and the mean change of those who improved