Table 3.

Scale responsiveness: analysis of variance of Rasch transformed 0–100, anchored to scoring algorithm.

	Baseline				Week 48				ANOVA
	x	SD	½ SD	N	x	SD	½ SD	F	p value	RP
Placebo whole sample (n = 498)
Original Physical Impacta	31.00	16.55	8.28	457	30.83	17.35	8.68	0.024	0.878	0.00
Revised Symptoms	31.39	15.32	7.66	457	31.11	16.15	8.08	0.078	0.780	0.01
Original Psychological Impact	33.16	17.97	8.99	457	30.73	18.41	9.21	4.254	0.039	0.60
Revised Psychological Impact	32.82	21.37	10.69	457	29.15	21.10	10.55	7.114	0.008	1.00
Original Physical Impactb	29.96	16.49	8.25	457	29.86	17.32	8.66	0.009	0.926	0.00
Revised General Limitation	27.19	19.06	9.53	457	26.99	20.42	10.21	0.023	0.880	0.00
Placebo sub-sample (n = 191)
Original Physical Impacta	40.15	13.35	6.68	182	40.66	13.64	6.82	0.132	0.717	0.28
Revised Symptoms	39.78	13.24	6.62	182	40.17	13.13	6.56	0.082	0.775	0.17
Original Psychological Impact	39.43	17.56	8.78	182	38.80	16.60	8.30	0.128	0.721	0.27
Revised Psychological Impact	38.93	21.24	10.62	182	37.48	19.28	9.64	0.474	0.491	1.00
Original Physical Impactb	40.03	13.41	6.71	182	40.56	13.72	6.86	0.143	0.705	0.30
Revised General Limitation	39.60	15.15	7.57	182	39.12	16.26	8.13	0.088	0.767	0.19
Treatment whole sample (n = 1011)
Original Physical Impacta	30.98	16.43	8.22	875	29.73	16.69	8.35	0.711	0.399	0.03
Revised Symptoms	30.89	15.29	7.65	874	30.06	15.47	7.74	1.494	0.222	0.07
Original Psychological Impact	32.92	17.12	8.56	873	29.96	18.04	9.21	13.265	0.000	0.60
Revised Psychological Impact	32.54	20.05	10.03	873	28.12	20.68	10.34	22.084	0.000	1.00
Original Physical Impactb	29.34	16.43	8.22	875	28.74	16.63	8.32	0.613	0.434	0.03
Revised General Limitation	26.22	19.30	9.65	875	25.92	19.47	9.74	0.112	0.738	0.01
Treatment sub-sample (n = 418)
Original Physical Impacta	39.34	13.37	6.69	333	39.50	12.89	6.44	0.029	0.865	0.00
Revised Symptoms	39.31	12.61	6.30	333	39.04	12.42	6.21	0.089	0.765	0.01
Original Psychological Impact	39.78	15.69	7.85	333	37.40	16.51	8.25	4.055	0.044	0.62
Revised Psychological Impact	39.37	18.95	9.48	332	35.77	19.38	9.69	6.536	0.011	1.00
Original Physical Impactb	39.25	13.45	6.72	333	39.40	12.93	6.47	0.025	0.874	0.00
Revised General Limitation	38.70	16.19	5.40	333	37.30	16.41	8.21	1.361	0.244	0.21

RP: relative measurement precision = (F-scale)/(F-scale with highest F value); ANOVA: analysis of variance. ^aOriginal Physical Impact Items anchored on the Physical Impact and General Symptoms merged items scales. ^bOriginal Physical Impact Items anchored on the Physical Impact and General Limitations merged items scales.