Psychometric properties of FACIT-Fatigue in systemic lupus erythematosus: a pooled analysis of three phase 3 randomised, double-blind, parallel-group controlled studies (BLISS-SC, BLISS-52, BLISS-76)

Journal of Patient-Reported Outcomes

Table 4 Mean FACIT-Fatigue scores across various criterion measures (pooled population)

Week	Patients, n	Category	Mean [95% CI]	F-value	p-value^a
	SELENA-SLEDAI
0	2489	< 6	33.8 [31.8, 35.9]	6.0	0.0025*
		6–9	31.0 [30.3, 31.8]
		≥10	30.2 [29.6, 30.8]
24	2313	< 6	37.2 [36.6, 37.9]	23.8	< 0.0001**
		6–9	34.7 [33.9, 35.5]
		≥10	33.1 [32.0, 34.2]
52	1990	< 6	37.6 [37.0, 38.3]	33.2	< 0.0001**
		6–9	34.4 [33.6, 35.3]
		≥10	32.0 [30.5, 33.4]
	PGA
0	2489	None/mild	33.8 [32.5, 35.2]	24.1	< 0.0001**
		Moderate	31.0 [30.4, 31.5]
		Severe	27.8 [26.6, 28.9]
24	2313	None/mild	38.1 [37.5, 38.8]	78.2	< 0.0001**
		Moderate	33.4 [32.8, 34.1]
		Severe	26.4 [23.9, 28.8]
52	1990	None/mild	37.9 [37.3, 38.5]	64.8	< 0.0001**
		Moderate	32.8 [32.0, 33.7]
		Severe	26.3 [23.2, 29.4]
	BILAG General A/B
0	2489	No	31.6 [31.1, 32.1]	132.8	< 0.0001
0	2489	Yes	22.7 [21.3, 24.1]	132.8	< 0.0001
24	2313	No	36.0 [35.6, 36.5]	90.6	< 0.0001
24	2313	Yes	24.3 [22.0, 26.7]	90.6	< 0.0001
52	1990	No	36.2 [35.7, 36.7]	63.0	< 0.0001
52	1990	Yes	23.6 [20.6, 26.7]	63.0	< 0.0001
	BILAG Musculoskeletal A/B
0	2489	No	34.0 [33.2, 34.8]	108.2	< 0.0001
0	2489	Yes	28.9 [28.4, 29.5]	108.2	< 0.0001
24	2313	No	37.2 [36.7, 37.8]	175.5	< 0.0001
24	2313	Yes	30.0 [29.0, 30.9]	175.5	< 0.0001
52	1990	No	37.5 [36.9, 38.0]	162.8	< 0.0001
52	1990	Yes	29.7 [28.6, 30.7]	162.8	< 0.0001

^ap-value testing: H0: μi = μj, for all i,j
*p < 0.05 for < 6 versus 6–9 (2.9; 95% CI: [0.7, 5.2]) or ≥ 10 (3.8; 95% CI: [1.6, 5.9]); **p < 0.05 for all pairwise comparisons
Spearman rank-order correlations were used to assess the relationship between changes in FACIT-Fatigue and the SELENA-SLEDAI and PGA
BILAG British Isles Lupus Assessment Group, CI confidence interval, FACIT Functional Assessment of Chronic Illness Therapy, PGA Physician’s Global Assessment, SELENA-SLEDAI Safety of Estrogens in Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index