title: Evaluation of the Intermittent Exotropia Questionnaire using Rasch analysis.
abstract: OBJECTIVE
  The Intermittent Exotropia Questionnaire (IXTQ) is a patient, proxy, and parental report of quality of life specific to children with intermittent exotropia. We refine the IXTQ using Rasch analysis to improve reliability and validity.
  
  
  METHODS
  Rasch analysis was performed on responses of 575 patients with intermittent exotropia enrolled from May 15, 2008, through July 24, 2013, and their parents from each of the 4 IXTQ health-related quality-of-life questionnaires (child 5 through 7 years of age and child 8 through 17 years of age, proxy, and parent questionnaires). Questionnaire performance and structure were confirmed in a separate cohort of 379 patients with intermittent exotropia. One item was removed from the 12-item child and proxy questionnaires, and response options in the 8- to 17-year-old child IXTQ and proxy IXTQ were combined into 3 response options for both questionnaires. Targeting was relatively poor for the child and proxy questionnaires. For the parent questionnaire, 3 subscales (psychosocial, function, and surgery) were evident. One item was removed from the psychosocial subscale. Resulting subscales had appropriate targeting.
  
  
  CONCLUSIONS
  The Rasch-revised IXTQ may be a useful instrument for determining how intermittent exotropia affects health-related quality of life of children with intermittent exotropia and their parents, particularly for cohort studies.
authors: Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota.
authors: David A
authors: DA
authors: Leske
authors: Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota.
authors: Jonathan M
authors: JM
authors: Holmes
authors: Jaeb Center for Health Research, Tampa, Florida.
authors: B Michele
authors: BM
authors: Melia
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005099:Exotropia / Q000523:psychology*; D005260:Female; D006304:Health Status; D006801:Humans; D007223:Infant; D008297:Male; D011788:Quality of Life / Q000523:psychology*; D015203:Reproducibility of Results; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires
references: J AAPOS. 2011 Apr;15(2):135-9
references: 21419677
references: J AAPOS. 2010 Jun;14(3):221-6
references: 20417138
references: J Cataract Refract Surg. 2010 Jul;36(7):1181-8
references: 20610098
references: Ophthalmic Epidemiol. 2010 Oct;17(5):282-91
references: 20868254
references: J AAPOS. 2011 Feb;15(1):24-8
references: 21315631
references: Invest Ophthalmol Vis Sci. 2010 Jun;51(6):2878-84
references: 20089878
references: Invest Ophthalmol Vis Sci. 2012 May;53(6):2630-9
references: 22447864
references: Ophthalmology. 2010 Jan;117(1):163-168.e1
references: 19896195
references: Invest Ophthalmol Vis Sci. 2010 May;51(5):2496-503
references: 20053981
references: J Cataract Refract Surg. 2010 May;36(5):718-32
references: 20457362
references: Ophthalmology. 2014 Dec;121(12):2299-310
references: 25234012