Psychometric properties of an Arabic version of the fatigue severity scale in patients with stroke

Background: Post-stroke fatigue is a common symptom which needs to be assessed by a psychometrically sound tool. Objectives: To investigate the psychometric properties of an Arabic version of the fatigue severity scale (FSS-A) in patients with stroke. Methods: An observational, cross-sectional design was applied to 147 survivors of first-time stroke and 70 healthy participants. Internal consistency was measured by Cronbach's α, while test-retest reliability was measured by intraclass correlation coefficients (ICCs). To assess validity, the FSS-A was correlated with the Fatigue Visual Analogue Scale (VAS-F), the Short Form 36 (SF-36) and its vitality domain (SF-36V), the stroke specific quality of life (SSQOL-A) and its energy domain (SSQOL-A-E), and the Beck Depression Inventory II (BDI-II). Results: The FSS-A showed excellent internal consistency (Cronbach's α = 0.934) and test-retest reliability (ICC = 0.920, 95% confidence interval (CI): 0.85-0.96). Exploratory factor analysis confirmed that the FSS-A is unidimensional. The FSS-A had high positive correlation with VAS-F, moderate positive correlation with BDI-II, high negative correlation with SSQOL-A-E and moderate negative correlations with SF-36, SF-36V, and SSQOL-A. It differentiated patients from healthy participants with a sensitivity of 78.4% and a specificity of 77.1%. The minimal detectable change with 95% CI was 1.02 (22.4%). Conclusions: The FSS-A showed good psychometric properties suggesting its usefulness as a fatigue evaluation tool in patients diagnosed with stroke.