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 2 Spearman correlations between FACIT-Fatigue and various measures (Week 24)

Domain	BLISS-SC	n	BLISS-52	n	BLISS-76	n	Pooled	n
SF-36v2
Physical component score	N/A	0	0.67	798	0.69	726	0.69	1524
Mental component score	N/A	0	0.74	798	0.70	726	0.70	1524
Physical functioning	N/A	0	0.66	811	0.66	735	0.66	1546
Role physical	N/A	0	0.73	811	0.76	736	0.74	1547
Bodily pain	N/A	0	0.62	813	0.72	734	0.68	1547
General health	N/A	0	0.61	806	0.60	733	0.61	1539
Vitality	N/A	0	0.79	810	0.83	736	0.82	1546
Social functioning	N/A	0	0.72	813	0.76	736	0.74	1549
Role emotional	N/A	0	0.68	810	0.67	733	0.66	1543
Mental health	N/A	0	0.68	810	0.61	736	0.62	1546
SELENA-SLEDAI	−0.17	759	− 0.04	809	− 0.16	735	− 0.13	2303
BILAG General	0.32	761	0.27	814	0.43	737	0.37	2312
BILAG Musculoskeletal	0.41	761	0.24	814	0.30	737	0.34	2312

Correlations: < 0.3, weak; ≤0.3 to < 0.6, moderate-strong; ≥0.6, strong
BILAG British Isles Lupus Assessment Group, FACIT Functional Assessment of Chronic Illness Therapy, N/A Not assessed, SELENA-SLEDAI Safety of Estrogens in Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index, SF-36v2 Short Form-36 Health Survey Version 2