title: Psychometric qualities of a brief self-rated fatigue measure: The Fatigue Assessment Scale.
abstract: OBJECTIVE
  The main aim of this study was to examine the dimensionality and psychometric qualities of a new 10-item fatigue measure, the Fatigue Assessment Scale (FAS).
  
  
  METHODS
  As part of a longitudinal study, the respondents, all workers with at least 20 working hours per week, completed the FAS, four related fatigue measures, a depression questionnaire, and an emotional stability scale.
  
  
  RESULTS
  The FAS had a high internal consistency. The pattern of correlations and factor analysis showed good convergent and divergent validity. The FAS correlated strongly with the other fatigue scales. In a factor analysis of the five fatigue questionnaires, the FAS had the highest factor loading on a clear one-factor solution. Moreover, factor analyses revealed that fatigue, on the one hand, and depression and emotional stability, on the other hand, are separate constructs. Finally, it was shown that 8 out of the 10 FAS items were unbiased concerning gender; two had a uniform bias.
  
  
  CONCLUSIONS
  The FAS represents a potentially valuable assessment instrument with promising internal consistency reliability and validity. Gender bias in the FAS does not have consequences for use of the FAS.
authors.affiliation: Department of Clinical Health Psychology, Tilburg University, PO Box 90153, The Netherlands. h.j.michielsen@kub.nl
authors.forename: Helen J
authors.initials: HJ
authors.lastname: Michielsen
authors.forename: Jolanda
authors.initials: J
authors.lastname: De Vries
authors.forename: Guus L
authors.initials: GL
authors.lastname: Van Heck
mesh_terms: D000328:Adult; D005221:Fatigue / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D015203:Reproducibility of Results; D012647:Self-Assessment; D012737:Sex Factors; D011795:Surveys and Questionnaires