Chronic fatigue: psychometric properties and updated norm values of the Chalder fatigue scale in a cross-sectional sample... 2025 Krakau et al

[Andy]

Full title: Chronic fatigue: psychometric properties and updated norm values of the Chalder fatigue scale in a cross-sectional sample representative of the German population


Abstract
Background
The Chalder Fatigue Scale (CFQ) is a commonly used self-report instrument assessing the severity and chronicity of fatigue. We examine the psychometric properties of the CFQ and provide updated normative data for the German general population.

Materials and Methods
The CFQ was administered to N = 2519 participants (16-96 years). Statistical analyses included the evaluation of the item properties, confirmatory factor analysis and examinig associations with mental health and sociodemographic data. CFQ cut-offs were used to estimate proportions of severe and chronic fatigue scores. We calculated percentile norms for the total sample and stratified by age groups and gender.

Results
Indicators of internal consistency reliability were high for the CFQ total and subscales (α = 0.84–0.94; ω = 0.86–0.95). We found excellent model fit for a one (χ2 = 196.011, df = 44, p ≤ .001; CFI=.991, RMSEA = 0.037, SRMR = 0.059) and two-factor solution (χ2 = 115.055, df = 42, p ≤ .001; CFI=.996, RMSEA = 0.026, SRMR = 0.045). The CFQ total scale showed low to moderate associations with depression (r = .49, p ≤ .001), anxiety (r = .45, p ≤ .001), and loneliness (r = .26, p ≤ .001), indicating acceptable discriminant validity. Current unemployment was a relevant sociodemographic correlate of fatigue severity (CFQ total: β =.38, se =.09, p ≤ .001). 14.2% of participants reported severe fatigue, while 4.3% reported being fatigued for at least six months (chronic fatigue).

Conclusion
The CFQ is a brief and reliable instrument for assessing fatigue in general population settings. The results are limited by the lack of comparison with other established fatigue questionnaires.

Open access

 

[Andy]

"Physical (e.g. reduced strength), cognitive (e.g. lack of concentration), and emotional (e.g. lack of energy) fatigue symptoms may be distinguished [Citation4]. The persistence of symptoms for at least six months is considered chronic fatigue (CF). Different criteria and case definitions have been proposed for the diagnosis of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) or systemic exertion intolerance disease (SEID), the term recommended by the Institutes of Medicine [Citation7]. Based on different definitions and assessment methods, prevalence estimates of 4 to 45% have been reported for severe fatigue in general population samples [Citation2,Citation8] and 2%–11% [Citation8,Citation9] for CF. Much lower prevalence rates of 0.007%–2.8% have been estimated for the diagnosis of CFS/ME [Citation9–12]."

 

[Andy]

"The abbreviation CFQ is commonly used to distinguish it from CFS. The scoring procedure of the instrument allows to differentiate between no fatigue and severe fatigue with an additional item to assess chronicity. According to Cella & Chalder [Citation22], the scale accurately discriminates between CFS cases and non-cases, especially at higher scores. Compared to other instruments, it may capture a wider range of fatigue severity, suggesting its usefulness in population-based and research settings [Citation19]. The CFQ is designed to capture physical (e.g. tiredness) and mental (e.g. impaired memory) dimensions of fatigue.

Debates about the dimensionality of fatigue are also reflected in various uni- and multidimensional questionnaires to assess fatigue and its components [Citation23,Citation24]. Martin et al. [Citation20] found support for the two-factor solution of the CFQ in the German general population. Based on data from 2004, they found that 7.4% of participants reported severe fatigue, and 6.1% reported CF. In the present study, we aimed to replicate the findings of Martin et al. [Citation20] on the psychometric properties of the instrument and to provide updated normative data for the CFQ total scale and both subdimensions, physical and mental fatigue."

 

[Trish]

For anyone relatively new to the subject, it's worth reading this thorough article explaining why the CFQ is badly flawed:
S4ME: Submission to the public review on common data elements for ME/CFS: Problems with the Chalder Fatigue Questionnaire

 

[NelliePledge]

Reliable

 

[rvallee]

The Chalder Fatigue Scale (CFQ) is a commonly used self-report instrument assessing the severity and chronicity of fatigue

It does neither of those things. Wut?

Hey, at least minor kudos for using "assessing" instead of the usual wildly misleading "measuring", but this is pathetic.

The CFQ is a brief and reliable instrument for assessing fatigue in general population settings. The results are limited by the lack of comparison with other established fatigue questionnaires.

It is brief, though obviously not reliable, but it's not possible to compare so that's an odd thing to say. How would that even work in the first place? Oh, right, fake mathemagics interpreting qualitative feelings. I guess they had nothing useful to say in conclusion.

Indicators of internal consistency reliability were high

It's a relative assessment for what is usually a highly fluctuating issue, it literally cannot have any "internal consistency reliability".

Biopsychosocial research continuing to not beat allegations of being completely useless nonsense.