title: Psychometric properties of the EuroQol Five Dimensional Questionnaire (EQ-5D-3L) in caregivers of autistic children.
abstract: OBJECTIVE
  This study aimed to ascertain the psychometric properties of EuroQol Five Dimensional Questionnaire (EQ-5D-3L) in primary caregivers of children with autism. The convergent validity, discriminant validity, known-groups validity, internal consistency reliability, and floor and ceiling effects of EQ-5D-3L were analyzed.
  
  
  METHODS
  A cross-sectional design was used for study purposes. Through an online survey, relevant study information was collected from 316 primary caregivers of children with autism. Study participants were from families of children with autism living in the United States who were registered with the Interactive Autism Network. Convergent validity of the EQ-5D-3L was assessed through its correlation with other measures of similar constructs. Discriminant validity was assessed by observing the correlation of EQ-5D-3L domains with theoretically unrelated constructs. Known-groups validity was tested by comparing EQ-5D-3L index and visual analog scale (VAS) scores across levels of autism severity among the care recipients. Internal consistency reliability of EQ-5D-3L was tested. Lastly, floor and ceiling effects of EQ-5D-3L were assessed.
  
  
  RESULTS
  More than 60 % of participants reported problems of 'anxiety/depression.' Convergent and discriminant validity of the EQ-5D-3L was good. Significant correlation (convergent validity) was observed among EQ-5D-3L index and VAS and (SF-12v2) physical component summary and mental component summary scores. Caregivers' EQ-5D-3L index and VAS scores varied by levels of autism severity among care recipients, providing evidence of known-groups validity. Reliability assessed through Cronbach's alpha was less than satisfactory; however, corrected item-total correlations were adequate.
  
  
  CONCLUSIONS
  The EQ-5D-3L is a psychometrically sound tool to elicit health state preferences among caregivers of children with autism.
authors.affiliation: Department of Pharmacy Administration, School of Pharmacy, The University of Mississippi , Faser Hall Room 236, PO Box 1848, University, MS, 38677, USA , rkhanna@olemiss.edu.
authors.forename: Rahul
authors.initials: R
authors.lastname: Khanna
authors.forename: Krutika
authors.initials: K
authors.lastname: Jariwala
authors.forename: John P
authors.initials: JP
authors.lastname: Bentley
mesh_terms: D000328:Adult; D001007:Anxiety; D001321:Autistic Disorder / Q000523:psychology*; D017028:Caregivers / Q000523:psychology*; D002648:Child; D003430:Cross-Sectional Studies; D003863:Depression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D011594:Psychometrics / Q000379:methods* / Q000706:statistics & numerical data; D011788:Quality of Life / Q000523:psychology*; D015203:Reproducibility of Results; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014481:United States