title: Measurement properties of the Patient-Rated Wrist and Hand Evaluation: Rasch analysis of responses from a traumatic hand injury population.
abstract: BACKGROUND
  The Patient-Rated Wrist and Hand Evaluation (PRWHE) is a self-reported assessment of pain and disability to evaluate outcome after hand injuries. Rasch analysis is an alternative strategy for examining the psychometric properties of a measurement scale based in item response theory, rather than classical test theory.
  
  
  OBJECTIVE
  This study used Rasch analysis to examine the content, scoring and measurement properties of the PRWHE.
  
  
  METHODS
  PRWHE scores (n = 264) from persons with a traumatic injury or reconstructive surgery to one hand were collected from an outpatient hand rehabilitation facility. Rasch analysis was conducted to assess how the PRWHE fit the Rasch model, confirms the scaling structure of the pain and disability subscales, and identifies any areas of bias from differential item functioning.
  
  
  RESULTS
  Rasch analysis of the PRWHE supports internal consistency of the scale (α = 0.96) and reliability (as measured by the person separation index) of 0.95. While gender, age, diagnosis, and duration since injury all systematically influenced how people scored the PRWHE, hand dominance and affected side did not. Rasch analysis supported a 3 subscale structure (pain, specific activities and usual activities) rather than the current divisions of pain and disability.
  
  
  CONCLUSIONS
  Initial examination of the PRWHE indicates the psychometric properties of consistency, reliability and responsiveness previously tested by classical methods are further supported by Rasch analysis. It also suggests the scale structure may be best considered as 3 subscales rather than simply pain and disability.
authors.affiliation: McMaster University, School of Rehabilitation Science, Hamilton, Ontario, Canada. packhamt@gmail.com
authors.forename: Tara
authors.initials: T
authors.lastname: Packham
authors.forename: Joy C
authors.initials: JC
authors.lastname: MacDermid
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D003627:Data Interpretation, Statistical; D004185:Disability Evaluation; D005260:Female; D006230:Hand Injuries / Q000503:physiopathology* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011594:Psychometrics; D015203:Reproducibility of Results; D012737:Sex Factors; D013997:Time Factors; D055815:Young Adult
keywords: Hand injuries; Patient-Rated Wrist and Hand Evaluation; Rasch analysis; Self-reported outcomes