title: Psychometric evaluation of the IWQOL-Lite (Spanish version) when applied to a sample of obese patients awaiting bariatric surgery.
abstract: BACKGROUND
  Obesity may have an impact on key aspects of health-related quality of life (HRQOL). In this context, the Impact of Weight Quality of Life (IWQOL) questionnaire was the first scale designed to assess HRQOL. The aim of the present study was twofold: to assess HRQOL in a sample of Spanish patients awaiting bariatric surgery and to determine the psychometric properties of the IWQOL-Lite and its sensitivity to detect differences in HRQOL across groups.
  
  
  METHODS
  Participants were 109 obese adult patients (BMI ≥ 35 kg/m(2)) from Barcelona, to whom the following measurement instruments were applied: IWQOL-Lite, Depression Anxiety Stress Scales, Brief Symptom Inventory, and self-perception items.
  
  
  RESULTS
  Descriptive data regarding the IWQOL-Lite scores obtained by these patients are reported. Principal components analysis revealed a five-factor model accounting for 72.05% of the total variance, with factor loadings being adequate for all items. Corrected item-total correlations were acceptable for all items. Cronbach's alpha coefficients were excellent both for the subscales (0.88-0.93) and the total scale (0.95). The relationship between the IWQOL-Lite and other variables supports the construct validity of the scale. Finally, sensitivity analysis revealed large effect sizes when comparing scores obtained by extreme BMI groups.
  
  
  CONCLUSIONS
  This is the first study to report the application of the IWQOL-Lite to a sample of Spanish patients awaiting bariatric surgery and to confirm that the Spanish version of the instrument has adequate psychometric properties.
authors: Department of Methodology for the Behavioural Sciences, University of Barcelona, Passeig Vall d'Hebron 171, 08035 Barcelona, Spain. anaandres@ub.edu
authors: Ana
authors: A
authors: Andrés
authors: Carmina
authors: C
authors: Saldaña
authors: Jordi
authors: J
authors: Mesa
authors: Albert
authors: A
authors: Lecube
mesh_terms: D000328:Adult; D001007:Anxiety / Q000209:etiology; D050110:Bariatric Surgery / Q000523:psychology*; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003863:Depression / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D009767:Obesity, Morbid / Q000523:psychology* / Q000601:surgery*; D018579:Patient Selection; D011594:Psychometrics; D011788:Quality of Life; D012649:Self Concept; D013030:Spain; D011795:Surveys and Questionnaires / Q000592:standards; D014177:Translations; D014850:Waiting Lists