title: Rasch analysis of SF-Qualiveen in multiple sclerosis.
abstract: BACKGROUND
  A 30-item Qualiveen questionnaire was developed to measure the impact of urinary problems on everyday living in spinal cord injury, and subsequently an 8-item SF-Qualiveen was developed for those with multiple sclerosis (MS). The validity of this short form has not been previously examined using modern psychometric techniques, such as the Rasch measurement model.
  
  
  OBJECTIVE
  The aim of this study is to test if the short form meets the requirements of the Rasch model.
  
  
  METHODS
  A total of 401 patients with clinically definite MS were given the questionnaire at three neuroscience centres in the UK.
  
  
  RESULTS
  A total of 258 patients (64.3% response) completed the questionnaire. The original scale failed to meet the expectations of the Rasch model. A two-testlet solution was sought to account for local dependence, differential item functioning and disordered thresholds. After the modifications were made the scale fitted the model (χ2= 5.93 P = 0.4305), had high internal consistency (α = 0.88) and was unidimensional.
  
  
  CONCLUSIONS
  SF-Qualiveen is a simple and valid measure of the impact of urinary problems in multiple sclerosis, which meets the requirements of the Rasch measurement model. Summed ordinal scores can be converted to interval-level using the transformation table provided.
authors.affiliation: University of Liverpool, Liverpool, United Kingdom.|The Walton Centre NHS Foundation Trust, Liverpool, United Kingdom.
authors.forename: Kristijonas
authors.initials: K
authors.lastname: Milinis
authors.affiliation: Swiss Paraplegic Research, Nottwil, Switzerland.
authors.forename: Alan
authors.initials: A
authors.lastname: Tennant
authors.affiliation: University of Liverpool, Liverpool, United Kingdom.|The Walton Centre NHS Foundation Trust, Liverpool, United Kingdom.
authors.forename: Carolyn
authors.initials: C
authors.lastname: A Young
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications*; D063868:Patient Outcome Assessment; D011594:Psychometrics / Q000592:standards; D011788:Quality of Life; D057566:Self Report; D011795:Surveys and Questionnaires / Q000592:standards; D001750:Urinary Bladder, Neurogenic / Q000175:diagnosis* / Q000209:etiology; D014555:Urination Disorders / Q000175:diagnosis* / Q000209:etiology; D055815:Young Adult
keywords: Rasch; SF-Qualiveen; multiple sclerosis; quality of life; urinary dysfunction