Validation and Application of the Dutch Fatigue Scale and the Dutch Exertion Fatigue Scale

Abstract

PURPOSE To develop and validate self-assessment and proxy assessment versions of two measurement instruments for fatigue, the Dutch Fatigue Scale (DUFS), based on NANDA characteristics and the Dutch Exertion Fatigue Scale (DEFS). METHODS Cross-sectional designs were employed to test content, construct, and criterion-related validity; internal consistency; sensitivity; specificity; and usefulness of both scales among patients with heart disease, postpartum women, and patients living in a home for the elderly. FINDINGS AND CONCLUSIONS ▪ Both scales showed sufficient reliability and validity. ▪ The DUFS (scale coefficient H= .48; KR-20 = .79) is suitable as a measurement instrument for the assessment of patients' fatigue. The DUFS may be used reliably and validly for group-level comparisons. ▪ The DEFS (scale coefficient H= .61; Cronbach's alpha = .91) is suitable as a measurement instrument for the assessment of patients' exertion fatigue. The DEFS may be used reliably and validly in clinical practice at individual level. ▪ Scale items are considered weak if H < .40, medium if H < .50, and strong when H≥.50. Using these criteria, the DUFS may be classified as a high medium scale and the DEFS as a strong scale. ▪ Comparisons of the average DUFS sum scores between nonfatigued and fatigued subjects, as well as between patients with chronic heart failure and post-natal women, and correlation coefficients performed with sociodemographic factors (age, gender, education) show that the DUFS may be used as a reliable and valid measurement tool for the accurate assessment of patients' fatigue. Comparison of the assessments of nonfatigued and fatigued domiciliary heart patients (self-assessment) and their significant others (proxy assessment) also show evidence of the reliability and validity of the DUFS as a measurement tool for the accurate assessment of patients' fatigue. ▪ Comparison of the assessments of nonexertion fatigue and exertion fatigue between domiciliary heart patients (self-assessment) and their significant others (proxy assessment) show that the DEFS is a reliable and valid measurement tool for the accurate assessment of patients' exertion fatigue.