Short fatigue questionnaire: screening for severe fatigue, by Adriaan Penson, Sylvia van Deuren, Margreet Worm-Smeitink, Ewald Bronkhorst, Frank HJ van den Hoogen, Baziel GM van Engelen, Marlies Peters, Gijs Bleijenberg, Jan H Vercoulen, Nicole Blijlevens, Eline van Dulmen-den Broeder, Jacqueline Loonen, Hans Knoop in Journal of Psychosomatic Research Vol 137, Oct 2020, 110229 [doi.org/10.1016/j.jpsychores.2020.110229]
Highlights:
- To optimally screen for severe fatigue, a short version of the Checklist Individual Strength was proposed: the Short Fatigue Questionnaire (SFQ)
- Psychometric properties of the SFQ are satisfying
- A cut-off score of 18 is recommended to identify severe fatigue
- Norm values are presented and can be used as reference values
- The SFQ is an excellent instrument to screen for severe fatigue
Abstract:
Objective:
To determine psychometric properties, a cut-off score for severe fatigue and normative data for the 4-item Short Fatigue Questionnaire (SFQ) derived from the multi-dimensional fatigue questionnaire Checklist Individual Strength (CIS).
T
he Shortened Fatigue Questionnaire (SFQ) [10] consists of four items (‘I feel tired’, ‘I tire easily‘, ‘I feel fit’ and ‘I feel physically exhausted’; see appendix B). Each item is scored on a 7-point Likert Scale, ranging from 1 ‘yes, that is true’ to 7 ‘no, that is not true’. Scores of items 1, 2 and 4 are reversed and then all item scores are added up which results in a total score varying from 4 to 28. Higher scores reflect a higher level of fatigue.
Methods:
Data of previous studies investigating the prevalence of fatigue in ten chronic conditions (n = 2985) and the general population (n = 2288) was used to determine the internal consistency (Cronbach’s alpha) of the SFQ, its relation with other fatigue measures (EORTC QLQ-30 fatigue subscale and digital fatigue diary), a cut-off score for severe fatigue (ROC analysis) and to examine whether the four SFQ items truly measure the same construct. Norms were calculated for ten patient groups and the Dutch general population.
Results:
Cronbach’s alpha of the SFQ were excellent in almost all groups.
Psychometric characteristics of the SFQ were shown to be adequate. Cronbach’s alpha was high for almost all study populations, except for the CFS population. A plausible explanation for the latter could be the fact that the CFS group scored extremely high on the SFQ decreasing the variance of the item- and total scores. The reason why this group scored this high on the SFQ is explained by the fact that one of the criteria to meet the case definition of CFS is scoring above the cut-off score of 35 on the CIS fatigue severity subscale. As the SFQ is derived from the CIS, this will lead to a restricted range of scores. This suggests that the internal consistency itself was not necessarily lower in the CFS population. The relation between the SFQ and other fatigue measures showed the construct validity to be satisfying.
Pearson’s correlations between the SFQ and the EORTC-QLQ-C30 fatigue subscale and a fatigue diary were respectively 0.76 and 0.68. ROC analysis showed an area under the curve of 0.982 (95% CI: 0.979–0.985) and cut-off score of 18 was suggested which showed a good sensitivity (0.984) and specificity (0.826) as well as excellent values for the positive and negative prediction values within all groups using the CIS as golden standard. Factor analysis showed a one factor solution (Eigenvalue: 3.095) with factor loadings of all items on the factor being greater than 0.87.
Conclusion:
The SFQ is an easy to use, reliable and valid instrument to screen for severe fatigue in clinical routine and research.

A total of 60 proteins in the ME/CFS patients were differentially expressed (P < 0.01, Log10 (Fold Change) > 0.2 and < −0.2). Comparison of the PCA selected subgroup of ME/CFS patients (9/11) with controls increased the number of proteins differentially expressed to 99. Of particular relevance to the core symptoms of fatigue and post-exertional malaise experienced in ME/CFS, a proportion of the identified proteins in the ME/CFS groups were involved in mitochondrial function, oxidative phosphorylation, electron transport chain complexes, and redox regulation. A significant number were also involved in previously implicated disturbances in ME/CFS, such as the immune inflammatory response, DNA methylation, apoptosis and proteasome activation.
In the present study, we identified fifty online forum (Reddit) posts, discussing the personal lived experience of Chronic Fatigue Syndrome during lockdown and the global pandemic. These posts were subject to inductive thematic analysis.
Chronic Fatigue Syndrome/Myalgic Encephalomyelits (CFS/ME) is a chronic disease with complex pathophysiology and unknown etiology. It occurs both in children and adolescents, as well as in adults, with equal frequency. The clinical course is characterized by progressive fatigue, a significant reduction in the body’s efficiency, lack of relief despite rest, and numerous accompanying symptoms. Pathognomonic symptom for PE is the increase in fatigue after physical or mental exertion and the persistence of these symptoms for several hours or days.
Adolescents with Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) appear to be more likely to experience anxiety and/or depression using 
Myalgic encephalomyelitis/chronic fatigue syndrome is characterized by persistent and disabling fatigue, exercise intolerance, cognitive difficulty, and musculoskeletal/joint pain. Post–exertional malaise is a worsening of these symptoms after a physical or mental exertion and is considered a central feature of the illness. Scant observations in the available literature provide qualitative assessments of post–exertional malaise in patients with myalgic encephalomyelitis/ chronic fatigue syndrome. To enhance our understanding, a series of outpatient focus groups were convened.
Two consecutive maximal cardiopulmonary exercise tests (CPETs) performed 24 hr apart
This article reviews the biological underpinnings of ME/CFS presentations, including the interacting roles of the gut microbiome/permeability,
Creatine supplementation may recharge creatine stores (at least in the skeletal muscles) but this does not inevitably lead to better clinical features in all PFS (postviral fatigue syndrome) patients. It might help some patients to perform more physical work without negative consequences yet creatine is probably less effective to tackle general fatigue and/or nervous system-specific signs and symptoms of PFS. We are still short of information. Does supplemental creatine even reach the brain in PFS, a major stumbling block for creatine delivery in clinical neurology.

