Measuring fatigue in clinical and community settings

Area of Science:

• Psychometrics
• Clinical Psychology
• Epidemiology

Background:

• The Chalder Fatigue Scale (CFQ) is a common tool for measuring fatigue.
• Its psychometric properties and ability to differentiate between groups require thorough examination.

Purpose of the Study:

• To evaluate the psychometric properties of the CFQ.
• To assess the scale's ability to discriminate between individuals with Chronic Fatigue Syndrome (CFS) and the general population.

Main Methods:

• Principal component analysis (PCA) was used to determine the underlying structure of the CFQ.
• Receiver-operating characteristic (ROC) curve analysis was employed to assess discriminative accuracy.
• Data were collected from 361 CFS patients and 1,615 community-dwelling individuals.

Main Results:

• PCA revealed two distinct components: physical fatigue and mental fatigue, in both CFS patients and the general population.
• The ROC analysis demonstrated strong discriminative ability, with an Area Under the Curve (AUC) of 0.91.
• The CFQ effectively differentiates between CFS patients and controls, particularly at higher fatigue scores.

Conclusions:

• Fatigue comprises separable physical and mental components.
• The CFQ is a reliable instrument for distinguishing between clinical fatigue (CFS) and nonclinical fatigue in the general population.