title: Chinese version of Impact of Weight on Quality of Life for Kids: psychometric properties in a large school-based sample.
abstract: The Impact of Weight on Quality of Life for Kids (IWQOL-Kids) is the first self-report questionnaire for assessing weight-related quality of life for youth. However, there is no Chinese version of IWQOL-Kids. Thus, the objective of this research was to translate IWQOL-Kids into Mandarin and evaluate its psychometric properties in a large school-based sample.
  
  
  
  The total sample included 2282 participants aged 11-18 years old, including 1703 non-overweight, 386 overweight and 193 obese students. IWQOL-Kids was translated and culturally adapted by following the international guidelines for instrument linguistic validation procedures. The psychometric evaluation included internal consistency, test-retest reliability, exploratory factor analysis (EFA), confirmatory factor analysis (CFA), convergent validity and discriminant validity.
  
  
  
  Cronbach's α for the Chinese version of IWQOL-Kids (IWQOL-Kids-C) was 0.956 and ranged from 0.891 to 0.927 for subscales. IWQOL-Kids-C showed a test-retest coefficient of 0.937 after 2 weeks and ranged from 0.847 to 0.903 for subscales. The original four-factor model was reproduced by EFA after seven iterations, accounting for 69.28% of the total variance. CFA demonstrated that the four-factor model had good fit indices with comparative fit index = 0.92, normed fit index = 0.91, goodness of fit index = 0.86, root mean square error of approximation = 0.07 and root mean square residual = 0.03. Convergent validity and discriminant validity were demonstrated with higher correlations between similar constructs and lower correlations between dissimilar constructs of IWQOL-Kids-C and PedsQL™ 4.0. The significant differences were found across the body mass index groups, and IWQOL-Kids-C had higher effect sizes than PedsQL™4.0 when comparing non-overweight and obese groups, supporting the sensitivity of IWQOL-Kids-C.
  
  
  
  IWQOL-Kids-C is a satisfactory, valid and reliable instrument to assess weight-related quality of life for Chinese children and adolescents aged 11-18 years old.
authors.affiliation: Medical Psychological Institute of The Second Xiangya Hospital, Central South University, Middle Ren-Min Road 139, Changsha, Hunan 410011, China.
authors.forename: Jinbo
authors.initials: J
authors.lastname: He
authors.affiliation: Medical Psychological Institute of The Second Xiangya Hospital, Central South University, Middle Ren-Min Road 139, Changsha, Hunan 410011, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Medical Psychological Institute of The Second Xiangya Hospital, Central South University, Middle Ren-Min Road 139, Changsha, Hunan 410011, China.
authors.forename: Xingwei
authors.initials: X
authors.lastname: Luo
authors.affiliation: Medical Psychological Institute of The Second Xiangya Hospital, Central South University, Middle Ren-Min Road 139, Changsha, Hunan 410011, China.
authors.forename: Taisheng
authors.initials: T
authors.lastname: Cai
authors.affiliation: Medical Psychological Institute of The Second Xiangya Hospital, Central South University, Middle Ren-Min Road 139, Changsha, Hunan 410011, China.
authors.forename: Siyao
authors.initials: S
authors.lastname: Wu
authors.affiliation: Medical Psychological Institute of The Second Xiangya Hospital, Central South University, Middle Ren-Min Road 139, Changsha, Hunan 410011, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Lu
mesh_terms: D000293:Adolescent; D001828:Body Image / Q000523:psychology*; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D002681:China; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D050177:Overweight / Q000523:psychology; D011594:Psychometrics; D011788:Quality of Life / Q000523:psychology*; D015203:Reproducibility of Results; D012574:Schools; D057566:Self Report; D018434:Sickness Impact Profile; D013334:Students; D011795:Surveys and Questionnaires / Q000592:standards*
keywords: adolescents; children; psychometric properties; weight-related quality of life