title: The Schwartz Cancer Fatigue Scale: testing reliability and validity.
abstract: OBJECTIVE
  To describe the psychometric development of the Schwartz Cancer Fatigue Scale (SCFS).
  
  
  METHODS
  A multiphase instrumentation study describing construct and operational definitions, informal and formal content validity, reliability, and validity analysis.
  
  
  METHODS
  Content validity established with 20 subjects. Reliability and validity evaluated with 166 subjects residing in diverse parts of the United States.
  
  
  RESULTS
  Eleven items that failed to show variance, had high interitem correlations, or failed to discriminate were eliminated. Factor analysis resulted in a four-factor solution that accounted for 70% of the variance. Cronbach's alpha for the total scale was estimated to be 0.96 and to be between 0.82 and 0.93 for the subscales.
  
  
  CONCLUSIONS
  The 28-item SCFS has demonstrated reliability and content and construct validity. Factor analysis supports the four subscales (physical, emotional, cognitive, and temporal). Preliminary construct validity has been demonstrated by differences in fatigue between those people who are currently receiving treatment and those who have completed treatment and by scores on a visual analogue scale of fatigue.
  
  
  CONCLUSIONS
  The SCFS may prove to be clinically relevant in assessing the effect of interventions to treat and manage cancer-related fatigue.
authors.affiliation: University of Utah College of Nursing, Salt Lake City, USA.
authors.forename: A L
authors.initials: AL
authors.lastname: Schwartz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005163:Factor Analysis, Statistical; D005221:Fatigue / Q000209:etiology* / Q000451:nursing / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications* / Q000451:nursing / Q000523:psychology; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards*