RT Journal Article
SR Electronic
T1 Minimal clinically important difference for 7 measures of fatigue in patients with systemic lupus erythematosus.
JF The Journal of Rheumatology
JO J Rheumatol
FD The Journal of Rheumatology
SP 635
OP 642
VO 35
IS 4
A1 Ewan C Goligher
A1 Jacques Pouchot
A1 Rollin Brant
A1 Raheem B Kherani
A1 J Antonio Aviña-Zubieta
A1 Diane Lacaille
A1 Allen J Lehman
A1 Stephanie Ensworth
A1 Jacek Kopec
A1 John M Esdaile
A1 Matthew H Liang
YR 2008
UL http://www.jrheum.org/content/35/4/635.abstract
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.