title: Application of Rasch analysis to the parent adherence report questionnaire in juvenile idiopathic arthritis.
abstract: BACKGROUND
  Adherence to treatment in children with juvenile idiopathic arthritis (JIA) is associated with better outcomes. Assessing patient adherence in JIA, as well as attitudes and beliefs about prescribed treatments, is important for the clinician in order to optimize patient management. The objective of the current study was to evaluate the psychometric properties of the Parent (proxy-report) Adherence Report Questionnaires (PARQ), which assesses beliefs and behaviors related to adherence to treatments prescribed for JIA.
  
  
  METHODS
  A Rasch analysis was conducted on data collected with parents of children with JIA from two studies in which the PARQ was used as a measure of adherence.
  
  
  RESULTS
  The PARQ showed preliminary evidence of multidimensionality with two factors, accounting for 38 % and 27 % of the variance respectively. The PARQ in its original version does not adhere to expectations of the Rasch model. A transformed version of the PARQ obtained by deletion of the general adherence scale and modification of visual analog scales into 5-point likert scales improved fit to the model and showed preliminary evidence of unidimensionality.
  
  
  CONCLUSIONS
  The PARQ was transformed based on the results of the Rasch analysis. The transformed version of the PARQ shows preliminary evidence of unidimensionality and may allow computation of a total score, although further testing is needed to verify these findings.
authors.affiliation: Children's Hospital of Eastern Ontario Research Institute, 401 Smyth Road, room R1132, Ottawa, Ontario, Canada. ktoupin@cheo.on.ca.|Department of Pediatrics, University of Ottawa, Ontario, Canada. ktoupin@cheo.on.ca.
authors.forename: Karine
authors.initials: K
authors.lastname: Toupin April
authors.affiliation: École de Réadaptation, Université de Montréal, and researcher, Centre de recherche interdisciplinaire en réadaptation (CRIR) - Institut de Réadaptation Gingras-Lindsay-de Montréal du CIUSS-Centre-Sud de Montréal, Montreal, Canada.
authors.forename: Johanne
authors.initials: J
authors.lastname: Higgins
authors.affiliation: École de Réadaptation and Institut de recherche en santé publique de l'Université de Montréal (IRSPUM), Université de Montréal, Centre de recherche interdisciplinaire en réadaptation (CRIR), Montreal, Canada.
authors.forename: Debbie
authors.initials: D
authors.lastname: Ehrmann Feldman
mesh_terms: D000293:Adolescent; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001171:Arthritis, Juvenile / Q000628:therapy*; D002648:Child; D005081:Exercise Therapy; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008297:Male; D015233:Models, Statistical; D010147:Pain Measurement; D010290:Parents; D010349:Patient Compliance; D026741:Physical Therapy Modalities; D025341:Principal Component Analysis; D011594:Psychometrics; D013165:Splints; D011795:Surveys and Questionnaires
chemical_list: D018501:Antirheumatic Agents
keywords: Juvenile arthritis; Patient compliance; Psychometrics; Questionnaires