title: Adolescent self-report and parent proxy-report of health-related quality of life: an analysis of validity and reliability of PedsQL 4.0 among a sample of Malaysian adolescents and their parents.
abstract: BACKGROUND
  The Pediatric Quality of Life Inventory Generic Core Scales (PedsQL) 4.0 is a generalized assessment of health-related quality of life (HRQoL) based on adolescent self-report and parent proxy-report. This study aims to determine the construct validity and reliability of PedsQL 4.0 among a sample of Malaysian adolescents and parents.
  
  
  METHODS
  A cross-sectional study was carried out at three selected public schools in the state of Selangor. A total of 379 Malaysian adolescents completed the PedsQL 4.0 adolescent self-report and 218 (55.9%) parents completed the PedsQL 4.0 parent proxy-report. Weight and height of adolescents were measured and BMI-for-age by sex was used to determine their body weight status.
  
  
  RESULTS
  There were 50.8% male and 49.2% female adolescents who participated in this study (14.25 ± 1.23 years). The prevalence of overweight and obesity (25.8%) was four times higher than the prevalence of severe thinness and thinness (6.1%). Construct validity was analyzed using Confirmatory Factor Analysis (CFA). Based on CFA, adolescent self-report and parent proxy-report met the criteria of convergent validity (factor loading > 0.5, Average Variance Extracted (AVE) > 0.5, Construct Reliability > 0.7) and showed good fit to the data. The adolescent self-report and parent proxy-report exhibited discriminant validity as the AVE values were larger than the R(2) values. Cronbach's alpha coefficients of the adolescent self-report (α = 0.862) and parent proxy-report (α = 0.922) showed these instruments are reliable. Parents perceived the HRQoL of adolescents was poorer compared to the perception of the adolescent themselves (t = 5.92, p < 0.01). There was no significant difference in total HRQoL score between male and female adolescents (t = 0.858, p > 0.05). Parent proxy-report was negatively associated with the adolescents' BMI-for-age (r = -0.152, p < 0.05) whereas no significant association was found between adolescent self-report and BMI-for-age (r = 0.001, p > 0.05).
  
  
  CONCLUSIONS
  Adolescent self-report and parent proxy-report of the PedsQL 4.0 are valid and reliable to assess HRQoL of Malaysian adolescents. Future studies are recommended to use both adolescent self-report and parent-proxy report of HRQoL as adolescents and parents can provide different perspectives on HRQoL of adolescents.
authors.affiliation: Department of Nutrition and Dietetics, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang Selangor Darul Ehsan, 43400, Kuala Lumpur, Malaysia. tinashanker@gmail.com.
authors.forename: Sanker
authors.initials: S
authors.lastname: Kaartina
authors.affiliation: Department of Nutrition and Dietetics, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang Selangor Darul Ehsan, 43400, Kuala Lumpur, Malaysia. chinys@upm.edu.my.|Research Centre of Excellence, Nutrition and Non-communicable Diseases, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Kuala Lumpur, Malaysia. chinys@upm.edu.my.
authors.forename: Yit Siew
authors.initials: YS
authors.lastname: Chin
authors.affiliation: Department of Nutrition and Dietetics, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang Selangor Darul Ehsan, 43400, Kuala Lumpur, Malaysia. fararezali@gmail.com.
authors.forename: Rezali
authors.initials: R
authors.lastname: Fara Wahida
authors.affiliation: Department of Nutrition and Dietetics, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang Selangor Darul Ehsan, 43400, Kuala Lumpur, Malaysia. fuichee88@gmail.com.
authors.forename: Fui Chee
authors.initials: FC
authors.lastname: Woon
authors.affiliation: Department of Nutrition and Dietetics, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang Selangor Darul Ehsan, 43400, Kuala Lumpur, Malaysia. soniahiew@gmail.com.
authors.forename: Chu Chien
authors.initials: CC
authors.lastname: Hiew
authors.affiliation: Department of Nutrition and Dietetics, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang Selangor Darul Ehsan, 43400, Kuala Lumpur, Malaysia. zalilah@upm.edu.my.|Research Centre of Excellence, Nutrition and Non-communicable Diseases, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Kuala Lumpur, Malaysia. zalilah@upm.edu.my.
authors.forename: Mohd Shariff
authors.initials: MS
authors.lastname: Zalilah
authors.affiliation: Department of Nutrition and Dietetics, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang Selangor Darul Ehsan, 43400, Kuala Lumpur, Malaysia. nasir@upm.edu.my.|Research Centre of Excellence, Nutrition and Non-communicable Diseases, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Kuala Lumpur, Malaysia. nasir@upm.edu.my.
authors.forename: Mohd Taib
authors.initials: MT
authors.lastname: Mohd Nasir
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology*; D000328:Adult; D001827:Body Height; D001835:Body Weight; D002648:Child; D003430:Cross-Sectional Studies; D005163:Factor Analysis, Statistical; D005260:Female; D006304:Health Status; D006801:Humans; D008296:Malaysia; D008297:Male; D008875:Middle Aged; D010290:Parents / Q000523:psychology*; D011594:Psychometrics / Q000295:instrumentation*; D011788:Quality of Life / Q000523:psychology*; D015203:Reproducibility of Results; D057566:Self Report; D012737:Sex Factors