Validation of an Arabic version of Fatigue Severity Scale

Abstract

Objectives:To develop and test the psychometric properties of an Arabic version of Fatigue Severity Scale (FSS-Ar) that can be used to measure fatigue in Arabic patients with disorders where fatigue is a major symptom.Methods:Forward and backward translations of FSS were undertaken to develop an Arabic version. The validity and reliability of the FSS-Ar was then tested on 28 patients with systemic lupus erythematosus (SLE), 24 patients with multiple sclerosis (MS), and 31 healthy subjects. Exploratory factor analysis and hypothesis testing methods were used to examine construct validity. The correlation between FSS-Ar and the vitality domain of the RAND 36-Item Health was examined to test construct validity. The study was conducted at the King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia between February and June 2012.Results:Using a score of ≥4.05 to define fatigue, 39 of 52 (75%) participants were fatigued compared with 10 out of 31 (32%) healthy participants. The correlation between the FSS-Ar and the vitality domain of the RAND-36 was acceptable (r = -0.46). Factor analysis showed that items of the FSS-Ar measured one underlying construct, namely, fatigue. Test-retest reliability and internal consistency of the FSS-Ar was acceptable (intraclass correlation coefficient model 2,1 = 0.80; Cronbach’s alpha = 0.84).Conclusion:The Arabic version of the FSS demonstrated acceptable psychometric properties and was able to differentiate between patients with SLE or MS, and healthy subjects.

Validity and reliability of the Fatigue Severity Scale in Finnish multiple sclerosis patients

“…Cronbach's alpha values did not differ significantly when one item of the FSS (range, 0.939–0.961) was deleted in a stepwise manner. Our results are in line with the previously reported high Cronbach's alpha values for the FSS among patients with MS, which have varied from 0.84 to 0.95 (Al‐Sobayel et al., ; Amtmann et al., ; Armutlu et al., ; Bakalidou et al., ; Ottonello et al., ; Valko et al., ). The optimal Cronbach's alpha range has been reported to be between 0.7 and 0.9 for internal consistency or item homogeneity, while values over 0.9 have been suggested to show item redundancy (Boyle, ).…”

“…Moderate/high correlations were found between the FSS score and perceived burden of the disease, quality of life, and disease severity. In previous studies the FSS has shown significant correlations with physical MS symptoms (Learmonth et al., ), disease severity (Armutlu et al., ; Flachenecker et al., ; Valko et al., ), depression (Armutlu et al., ; Bakalidou et al., ; Flachenecker et al., ), pain (Amtmann et al., ), and quality of life (Al‐Sobayel et al., ; Bakalidou et al., ). The results also confirmed the hypothesized group differences based on previous findings concerning employment status (Johansson et al., ; Mills & Young, ), disability (Amtmann et al., ; Armutlu et al., ; Mills & Young, ; Valko et al., ), disease phenotype (Mills & Young, ), as well as the demographic factors, age and gender (Valko et al., ).…”

“…Divergent validity has been supported by the differences found between MS patients and healthy controls in the FSS (Armutlu et al., ; Bakalidou et al., ; Valko et al., ). The FSS has shown high internal consistency as analysed with Cronbach's alpha (Al‐Sobayel et al., ; Amtmann et al., ; Armutlu et al., ; Bakalidou et al., ; Lerdal et al., ; Ottonello et al., ; Valko et al., ) as well as high test‐retest reliability (Kleinman et al., ; Krupp et al., ; Learmonth et al., ; Rietberg et al., ).…”

“…Validation studies have been conducted with the English (Amtmann et al, 2012;Krupp et al, 1989), Arabic (Al-Sobayel et al, 2016), Turkish (Armutlu et al, 2007), Swiss (Valko et al, 2008), Norwegian (Lerdal, Wahl, Rustoen, Hanestad, & Moum, 2005), German (Rietberg, van Wegen, & Kwakkel, 2010), Greek (Bakalidou, Skordilis, Giannopoulos, Stamboulis, & Voumvourakis, 2013), Italian (Ottonello et al, 2016), Portuguese (Laranjeira, 2012), and Persian (Fereshtehnejad et al, 2013) versions of the FSS. The assessments of the psychometric properties based on the classical test theory have shown moderate/high correlations between the FSS and other fatigue scales (Amtmann et al, 2012;Flachenecker et al, 2002;Krupp et al, 1989;Learmonth et al, 2013;Rietberg et al, 2010).…”

“…The assessments of the psychometric properties based on the classical test theory have shown moderate/high correlations between the FSS and other fatigue scales (Amtmann et al, 2012;Flachenecker et al, 2002;Krupp et al, 1989;Learmonth et al, 2013;Rietberg et al, 2010). Significant correlations between the FSS and other clinical and health-related parameters, such as disease severity (Amtmann et al, 2012;Armutlu et al, 2007;Flachenecker et al, 2002;Valko et al, 2008), depression (Amtmann et al, 2012;Armutlu et al, 2007;Bakalidou et al, 2013;Flachenecker et al, 2002), pain (Amtmann et al, 2012), and quality of life (Al-Sobayel et al, 2016;Bakalidou et al, 2013) have been reported. Divergent validity has been supported by the differences found between MS patients and healthy controls in the FSS (Armutlu et al, 2007;Bakalidou et al, 2013;Valko et al, 2008).…”