title: Inventory of Determinants of Obesity-Related Behaviors in Adolescents: Development and Psychometric Characteristics.
abstract: BACKGROUND
  The rising prevalence of childhood obesity is a major health problem worldwide. Hence, there is a growing need for health professionals to become capable of assessing the factors that determine lifestyle in a culturally relevant manner.
  
  
  OBJECTIVE
  This study aimed to develop and assess a questionnaire for measuring determinants of obesity-related behaviors in Tehranian adolescents.
  
  
  METHODS
  Based on the results of a qualitative study and an extensive literature review, the 44-item "Inventory of determinants of obesity-related behaviors in adolescents (IDOBA)" with eight subscales was developed: 1) unhealthy nutrition and physical inactivity; 2) stress-related eating; 3) perceived inability; 4) perceived lack of threat; 5) perceived priority of educational achievement; 6) perceived acceptability; 7) motivation loss; and 8) lack of support. Validity of IDOBA was assessed, utilizing face, content, and construct validity methods. To confirm face validity, ten overweight/obese adolescents completed the questionnaire. To calculate content validity ratio (CVR) and content validity index (CVI), a different panel of ten experts commented independently on the necessity, relevance, clarity, and simplicity of each item. To assess construct validity using exploratory factor analysis (EFA), a total of 478 adolescents (57.7% male) aged 13 to 18 years, who were recruited from schools, participated in the study. Confirmatory factor analysis (CFA) was used to test whether the data fit the hypothesized measurement model that was derived from EFA. Test-retest and internal consistency methods were used to assess reliability of the IDOBA scale.
  
  
  RESULTS
  All items were perceived as relevant and comprehendible by adolescents. Content validity was confirmed by the panel of experts. The internal consistency, as measured by Cronbach's alpha coefficients, exceeded the minimum reliability standard of 0.60 for eight subscales. No ceiling effects were observed. Detected floor effects ranged from 0.2% for perceived acceptability subscale score to 18.8% for lack of threat subscale score. The EFA suggested an eight-factor construct and the results of the CFA indicated acceptable fit indices for the proposed model. All subscales demonstrated satisfactory test-retest reliability (intra-class correlation coefficient, 0.42 - 0.91) over one month.
  
  
  CONCLUSIONS
  Results provided initial evidence that the IDOBA is a valid and reliable instrument for measuring determinants of obesity-related behaviors in Iranian adolescents, indicating that the questionnaire can be used in future weight management programs for Tehranian adolescents.
authors.affiliation: Research Center for Social Determinants of Endocrine Health, Obesity Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Parisa
authors.initials: P
authors.lastname: Amiri
authors.affiliation: Department of Health Education, Tarbiat Modares University, Tehran, IR Iran.
authors.forename: Fazlollah
authors.initials: F
authors.lastname: Ghofranipour
authors.affiliation: Research Center for Social Determinants of Endocrine Health, Obesity Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Sara
authors.initials: S
authors.lastname: Jalali-Farahani
authors.affiliation: Department of Nursing, Tarbiat Modares University, Tehran, IR Iran.
authors.forename: Fazlollah
authors.initials: F
authors.lastname: Ahmadi
authors.affiliation: Obesity Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
authors.forename: Farhad
authors.initials: F
authors.lastname: Hosseinpanah
authors.affiliation: Department of Psychology, Shahid Beheshti University, Tehran, IR Iran.
authors.forename: Haidar Ali
authors.initials: HA
authors.lastname: Hooman
authors.affiliation: Research Center for Social Determinants of Endocrine Health, Obesity Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran ; Students' Research Committee, Shahid Beheshti University of Medical Sciences, Tehran,IR Iran.
authors.forename: Parnian
authors.initials: P
authors.lastname: Parvin
authors.affiliation: Research Center for Social Determinants of Endocrine Health, Obesity Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran ; Students' Research Committee, Shahid Beheshti University of Medical Sciences, Tehran,IR Iran.
authors.forename: Mohammadreza
authors.initials: M
authors.lastname: Ghasemi
keywords: Adolescent; Iran; Obesity; Reliability; Validity