Short fatigue questionnaire: Screening for severe fatigue.

Area of Science:

• Psychometrics
• Clinical Assessment
• Fatigue Research

Background:

• Fatigue is a common and debilitating symptom in numerous chronic conditions.
• Accurate and efficient measurement of fatigue is crucial for diagnosis and management.
• Existing fatigue questionnaires may require further validation or optimization for specific populations.

Purpose of the Study:

• To evaluate the psychometric properties of the 4-item Short Fatigue Questionnaire (SFQ).
• To establish a cut-off score for identifying severe fatigue using the SFQ.
• To generate normative data for the SFQ across various chronic conditions and the general population.

Main Methods:

• Utilized data from 2985 patients with chronic conditions and 2288 individuals from the general population.
• Assessed internal consistency (Cronbach's alpha) and construct validity through correlations with established fatigue measures.
• Employed Receiver Operating Characteristic (ROC) analysis to determine an optimal cut-off score for severe fatigue.

Main Results:

• The SFQ demonstrated excellent internal consistency (Cronbach's alpha) across most groups studied.
• Strong correlations were observed between the SFQ and other fatigue measures (r=0.76 with EORTC QLQ-C30, r=0.68 with digital diary).
• ROC analysis identified a cut-off score of 18 with high sensitivity (0.984) and specificity (0.826) for severe fatigue, validated against the Checklist Individual Strength (CIS).

Conclusions:

• The 4-item Short Fatigue Questionnaire (SFQ) is a psychometrically sound instrument.
• The SFQ is a reliable and valid tool for screening severe fatigue in both clinical settings and research.
• The identified cut-off score and normative data enhance the utility of the SFQ for practical application.