Reliability and Validity of the Modified Korean Version of the Chalder Fatigue Scale (mKCFQ11) 2020, Yo-Chan Ahn et al

[Sly Saint]

Abstract
Fatigue can accompany various diseases; however, fatigue itself is a key symptom for patients with chronic fatigue syndrome (CFS). Due to the absence of biological parameters for the diagnosis and severity of CFS, the assessment tool for the degree of fatigue is very important. This study aims to verify the reliability and validity of the modified Korean version of the Chalder Fatigue Scale (mKCFQ11).

This study was performed using data from 97 participants (Male: 37, Female: 60) enrolled in a clinical trial for an intervention of CFS. The analyses of the coefficient between the mKCFQ11 score and the Fatigue Severity Scale (FSS), the Visual Analogue Scale (VAS) or the 36-item Short-Form Health Survey (SF-36) at two time points (baseline and 12 weeks) as well as their changed values were conducted.

The mKCFQ11 showed strong reliability, as evidenced by the Cronbach’s alpha coefficient of 0.967 for the whole item and two subclasses (0.963 for physical and 0.958 for mental fatigue) along with the suitable validity of the mKCFQ11 structure shown by the principal component analysis.

The mKCFQ11 scores also strongly correlated (higher than 0.7) with the VAS, FSS and SF-36 on all data from baseline and 12 weeks and changed values. This study demonstrated the clinical usefulness of the mKCFQ11 instrument, particularly in assessing the severity of fatigue and the evaluation of treatments for patients suffering from CFS.

https://www.mdpi.com/2227-9032/8/4/427

eta:
(This article belongs to the Special Issue ME/CFS – the Severely and Very Severely Affected)

 

[ME/CFS Skeptic]

This is interesting

The CFQ was initially developed as a four-point scale that compares to the “usual” status, and thus, it is difficult to measure the change in fatigue severity for certain periods. Therefore, we slightly modified it into a 10-point Likert scale (between normal and worst status) to describe their illness condition after treatment, called the Modified Korean Version of the Chalder Fatigue Scale (mKCFQ11)

The original version of the CFQ consists of 11 items to determine the fatigue-related status by comparing to the “usual” condition: “Less than usual”, “No more than usual”, “More than usual”, and “Much more than usual”. However, the reference point (“usual”) made it difficult for Korean patients to express their illness status, especially for patients with CFS due to the long-term duration of this condition, which could be over 10 years, or the very frequent childhood diagnosis. Furthermore, this “usual”-based comparison of illness condition at certain time points was not easily adapted to measure the changed score of fatigue severity in clinical trials of intervention. Therefore, we slightly modified it into a 10-point Likert scale as (0 = not at all to 9 = unbearably severe condition) for the same 11 questions (physical fatigue questions 1st–7th items, and mental fatigue 8th–11th items, total score range 0–99).

 

[Trish]

So it's not the CFQ. Main flaws of CFQ include the nonsensical 'better than before' option that clearly gets misused, and the ceiling effect. This Korean version sorts out those problems and makes it more like other fatigue scales.

Still retains the flaw of mixing physical, psychological/depression and cognitive fatigue.

Edited to add second sentence.

 

[Barry]

However, the reference point (“usual”) made it difficult for Korean patients to express their illness status, especially for patients with CFS due to the long-term duration of this condition, which could be over 10 years, or the very frequent childhood diagnosis. Furthermore, this “usual”-based comparison of illness condition at certain time points was not easily adapted to measure the changed score of fatigue severity in clinical trials of intervention.

Not just for Koreans of course. The CFQ basically flawed.

 

[Snow Leopard]

Yes it's less terrible than the original, but it still suffers other flaws, such as no one has ever bothered to ask patients whether they think it is useful...