Article

OBJECTIVE: To investigate an appropriate scoring system and unidimensionality
using Rasch analysis, discriminant validity, and reliability of the Fatigue
Severity Scale (FSS) in people with chronic neck pain. DESIGN: Cross-sectional.
SETTING: Tertiary institution. PARTICIPANTS: Patients with chronic neck pain
(n=100) and asymptomatic controls (n=40). INTERVENTIONS: Not applicable. MAIN
OUTCOME MEASURE: The FSS. RESULTS: Twenty-six of the 100 participants with
chronic neck pain agreed to complete the FSS again within 1 week after the first
administration for the assessment of the test-retest reliability. Two items
obviously threatening unidimensionality were eliminated, and the 7-item FSS was
developed through Rasch analyses. The 7-item FSS demonstrated the appropriateness
of its 7-point scale and adequate internal consistency (Rasch-generated
reliability, .83-.91). The 7-item FSS had a negligible floor effect (1%) and
ceiling effect (2%). The item-person map demonstrated limited distribution of
item difficulty in comparison with the distribution of person ability. The
chronic neck pain group demonstrated significantly (P<.001) higher scores in the
7-item FSS than the control group, indicating discriminant validity. The 7-item
FSS also demonstrated adequate test-retest reliability with a mean interval of
4.1 days (n=26) for each item (quadratic-weighted kappa=.83-.94), and as a whole
(intraclass correlation coefficient=.95). A 0-to-100 scale table reflecting Rasch
scores was developed, and the minimum detectable change was 9.5 in the 0 to 100
scale. CONCLUSION: The 7-item FSS appears unidimensional and reliable, and can be
used quickly in clinical practice to gain a basic understanding of fatigue
symptoms in people with chronic neck pain. Further, it is possible to modify the
7-item FSS to enhance discriminant ability within people with chronic neck pain
by adding additional items, enlarging the distribution of item difficulty.
CI - Copyright (c) 2013 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS