title: A Swedish version of the 16-item Parkinson fatigue scale (PFS-16).
abstract: BACKGROUND
  The PFS-16 is a 16-item fatigue scale for Parkinson's disease (PD) developed in the UK. However, documented translations and psychometric evaluations are sparse.
  
  
  OBJECTIVE
  To translate the PFS-16 into Swedish and conduct initial testing of its psychometric properties.
  
  
  METHODS
  Following translation, the PFS-16 was administered twice (2 weeks apart) to 30 people with PD (18 men; mean age/PD duration, 60/6.4 years). The PFS-16 uses five response categories (1 = strongly disagree, 5 = strongly agree), and the total score is the mean over item scores (1-5; 5 = more fatigue). An alternative, dichotomised scoring method has also been suggested (total score, 0-16; 16 = more fatigue). Scaling assumptions, floor/ceiling effects, reliability, and correlations with other variables including the generic fatigue scale Functional Assessment of Chronic Illness Therapy - Fatigue scale (FACIT-F) were tested.
  
  
  RESULTS
  Scaling assumptions were generally supported for the original scoring [range of mean (SD) item scores, 2.1-3.3 (1-1.4); corrected item-total correlations, ≥0.40], but not for dichotomised scoring [range of mean (SD) item scores, 0.1-0.6 (0.3-0.5); corrected item-total correlations, ≥0.16]. Reliabilities were ≥0.88. Floor effects were absent (original scoring) and >23% (dichotomised scoring); there were no ceiling effects. Correlations with other variables followed expectations (e.g. -0.88 with FACIT-F scores).
  
  
  CONCLUSIONS
  These observations support the psychometric properties of the Swedish PFS-16, but cautions against dichotomised scoring.
authors.affiliation: School of Health and Society, Kristianstad University, Sweden. Peter.Hagell@hkr.se
authors.forename: P
authors.initials: P
authors.lastname: Hagell
authors.forename: T
authors.initials: T
authors.lastname: Rosblom
authors.forename: S
authors.initials: S
authors.lastname: Pålhagen
mesh_terms: D000328:Adult; D000368:Aged; D005221:Fatigue / Q000145:classification* / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications*; D011594:Psychometrics / Q000295:instrumentation*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013548:Sweden; D014175:Translating