title: Rasch Analysis of the Adult Strabismus Quality of Life Questionnaire (AS-20) among Chinese Adult Patients with Strabismus.
abstract: BACKGROUND
  The impact of strabismus on visual function, self-image, self-esteem, and social interactions decrease health-related quality of life (HRQoL).The purpose of this study was to evaluate and refine the adult strabismus quality of life questionnaire (AS-20) by using Rasch analysis among Chinese adult patients with strabismus.
  
  
  METHODS
  We evaluated the fitness of the AS-20 with Rasch model in Chinese population by assessing unidimensionality, infit and outfit, person and item separation index and reliability, response ordering, targeting and differential item functioning (DIF).
  
  
  RESULTS
  The overall AS-20 did not demonstrate unidimensional; however, it was achieved separately in the two Rasch-revised subscales: the psychosocial subscale (11 items) and the function subscale (9 items). The features of good targeting, optimal item infit and outfit, and no notable local dependence were found for each of the subscales. The rating scale was appropriate for the psychosocial subscale but a reduction to four response categories was required for the function subscale. No significant DIF were revealed for any demographic and clinical factors (e.g., age, gender, and strabismus types).
  
  
  CONCLUSIONS
  The AS-20 was demonstrated by Rasch analysis to be a rigorous instrument for measuring health-related quality of life in Chinese strabismus patents if some revisions were made regarding the subscale construct and response options.
authors.affiliation: School of Nursing, Third Military Medical University, Chongqing, China.
authors.forename: Zonghua
authors.initials: Z
authors.lastname: Wang
authors.affiliation: School of Nursing, Third Military Medical University, Chongqing, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Ophthalmology, Daping Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Xingli
authors.initials: X
authors.lastname: Luo
authors.affiliation: Department of Ophthalmology, Southwest Eye Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Ophthalmology, Xinqiao Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Xi
authors.initials: X
authors.lastname: She
authors.affiliation: Department of Gastroenterology, the 324th Hospital of PLA, Chongqing, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Ophthalmology, Daping Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Honghua
authors.initials: H
authors.lastname: Yin
authors.affiliation: School of Nursing, Third Military Medical University, Chongqing, China.
authors.forename: Xianyuan
authors.initials: X
authors.lastname: Wang
mesh_terms: D000328:Adult; D002681:China / Q000453:epidemiology / Q000208:ethnology; D005260:Female; D006801:Humans; D008297:Male; D015233:Models, Statistical; D011788:Quality of Life; D013285:Strabismus / Q000503:physiopathology / Q000523:psychology*; D011795:Surveys and Questionnaires