PT  - JOURNAL ARTICLE
AU  - Ewan C Goligher
AU  - Jacques Pouchot
AU  - Rollin Brant
AU  - Raheem B Kherani
AU  - J Antonio Aviña-Zubieta
AU  - Diane Lacaille
AU  - Allen J Lehman
AU  - Stephanie Ensworth
AU  - Jacek Kopec
AU  - John M Esdaile
AU  - Matthew H Liang
TI  - Minimal clinically important difference for 7 measures of fatigue in patients with systemic lupus erythematosus.
DP  - 2008 Apr 01
TA  - The Journal of Rheumatology
PG  - 635--642
VI  - 35
IP  - 4
4099  - http://www.jrheum.org/content/35/4/635.short
4100  - http://www.jrheum.org/content/35/4/635.full
SO  - J Rheumatol2008 Apr 01; 35
AB  - OBJECTIVE: To determine the minimal clinically important difference (MCID) for 7 measures of fatigue in patients with systemic lupus erythematosus (SLE). METHODS: Study subjects completed 7 fatigue instruments [Fatigue Severity Scale (FSS), Multidimensional Assessment of Fatigue (MAF), Multidimensional Fatigue Inventory (MFI), Vitality scale of the MOS-SF-36, Chalder Fatigue Scale (CFS), Functional Assessment of Chronic Illness Therapy-Fatigue, and a global Rating Scale (RS)] and then participated in a series of interviews with other study participants comparing their fatigue with one another. Each interview participant rated the difference in their fatigue levels on a 7-point transition scale. The MCID was estimated from the mean difference in fatigue scores between each pair of interview participants based on their subjective rating of fatigue contrast. The MCID was also estimated using linear regression modeling. RESULTS: Eighty patients with SLE participated. Patients reported significant levels of fatigue [mean normalized (0 = none, 100 = maximum) fatigue scores for the 7 instruments ranged from 49.8 (CFS) to 71.1 (FSS)]. The MCID of "a little more" fatigue tended to be greater than the MCID for a "little less fatigue" and differed significantly for FSS and MAF. The MCID of normalized scores estimated by linear regression ranged from 7.0 (CFS) to 14.3 (MFI). CONCLUSION: Fatigue is a common and debilitating component of SLE. Estimates of MCID will help to interpret changes observed in a fatigue score and will be critical in estimating sample size requirements for clinical trials including fatigue as an outcome.