title: Applicability, validity, and reliability of the Piper Fatigue Scale in postpolio patients.
abstract: OBJECTIVE
  To identify a scale that is potentially applicable for measuring the fatigue in postpolio patients and to evaluate its validity and reliability in this population.
  
  
  METHODS
  Interview survey of 64 individuals with postpolio syndrome and 25 healthy controls of similar age range, with retest in a subset of postpolio patients. The sample was recruited from a postpolio support group, a postpolio clinic, and the general community. Subjects completed the Piper Fatigue Scale, the Beck Depression Inventory, and the Chalder Fatigue Questionnaire during the interview.
  
  
  RESULTS
  Face and content validity of the Piper Fatigue Scale was established by a team of experts and by a group of postpolio patients. The postpolio subjects had significantly higher Piper Fatigue Scale scores than the healthy control subjects (P < 0.001), demonstrating extreme groups validity. Convergent validity was shown with a strong positive correlation between Piper Fatigue Scale scores and Chalder Fatigue Questionnaire scores (r = 0.80). Reliability was also demonstrated with the Piper Fatigue Scale's high internal consistency (alpha = 0.98) and strong test-retest agreement (intraclass correlation coefficient = 0.98).
  
  
  CONCLUSIONS
  The Piper Fatigue Scale is a valid and reliable tool for measuring postpolio fatigue. This scale may be useful in other studies of postpolio fatigue, including those gauging the effectiveness of various treatments for this fatigue.
authors.affiliation: Centre for Neuroscience, University of Alberta, Edmonton, Canada.
authors.forename: Fay J
authors.initials: FJ
authors.lastname: Strohschein
authors.forename: Carl G
authors.initials: CG
authors.lastname: Kelly
authors.forename: Anita G
authors.initials: AG
authors.lastname: Clarke
authors.forename: Chris F
authors.initials: CF
authors.lastname: Westbury
authors.forename: Ashfaq
authors.initials: A
authors.lastname: Shuaib
authors.forename: K Ming
authors.initials: KM
authors.lastname: Chan
mesh_terms: D000203:Activities of Daily Living; D004185:Disability Evaluation; D005221:Fatigue / Q000145:classification* / Q000175:diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016262:Postpoliomyelitis Syndrome / Q000145:classification* / Q000175:diagnosis; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires