title: Assessing quality of life in severe obesity: development and psychometric properties of the ORWELL-R.
abstract: OBJECTIVE
  Several health-related quality-of-life (HRQoL) dimensions are affected by obesity. Our goal was to characterize the psychometric properties of the ORWELL-R, a new obesity-related quality-of-life instrument for assessing the "individual experience of overweightness".
  
  
  METHODS
  This psychometric assessment included two different samples: one multicenter clinical sample, used for assessing internal consistency, construct validity and temporal reliability; and a community sample (collected through a cross-sectional mailing survey design), used for additional construct validity assessment and model fit confirmation.
  
  
  RESULTS
  Overall, 946 persons participated (188 from the clinical sample; 758 from community sample). An alpha coefficient of 0.925 (clinical sample) and 0.934 (community sample) was found. Three subscales were identified (53.2 % of variance): Body environment experience (alpha = 0.875), Illness perception and distress (alpha = 0.864), Physical symptoms (alpha = 0.674). Adequate test-retest reliability has been confirmed (ICC: 0.78 for the overall score). ORWELL-R scores were worse in the clinical sample. Worst HRQoL, as measured by higher ORWELL-R scores, was associated with BMI increases. ORWELL-R scores were associated with IWQOL-Lite and lower scores in happiness.
  
  
  CONCLUSIONS
  ORWELL-R shows good internal consistency and adequate test-retest reliability. Good construct validity was also observed (for convergent and discriminant validity) and confirmed through confirmatory factor analysis (in both clinical and community samples). Presented data sustain ORWELL-R as a reliable and useful instrument to assess obesity-related QoL, in both research and clinical contexts.
authors.affiliation: Serviço de Endocrinologia, Hospital de Santa Maria, CHLN/Faculdade de Medicina da Universidade de Lisboa, Piso 6, Av. Prof. Egas Moniz, 1649-035, Lisbon, Portugal. jose.camolas@gmail.com.
authors.forename: José
authors.initials: J
authors.lastname: Camolas
authors.affiliation: Espírito Santo Hospital, Evora, Portugal.
authors.forename: André
authors.initials: A
authors.lastname: Ferreira
authors.affiliation: Diabetes Agency, Careggi Hospital, Florence, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Mannucci
authors.affiliation: Serviço de Endocrinologia, Hospital de Santa Maria, CHLN/Faculdade de Medicina da Universidade de Lisboa, Piso 6, Av. Prof. Egas Moniz, 1649-035, Lisbon, Portugal.
authors.forename: Mário
authors.initials: M
authors.lastname: Mascarenhas
authors.affiliation: Espírito Santo Hospital, Evora, Portugal.
authors.forename: Manuel
authors.initials: M
authors.lastname: Carvalho
authors.affiliation: Faculty of Nutrition and Food Sciences, University of Porto, Porto, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Moreira
authors.affiliation: Serviço de Endocrinologia, Hospital de Santa Maria, CHLN/Faculdade de Medicina da Universidade de Lisboa, Piso 6, Av. Prof. Egas Moniz, 1649-035, Lisbon, Portugal.
authors.forename: Isabel
authors.initials: I
authors.lastname: do Carmo
authors.affiliation: Instituto de Medicina Preventiva e Saúde Pública, Faculdade de Medicina da Universidade de Lisboa/DECO PROTESTE, Edf. Egas Moniz, Av. Prof. Egas Moniz, 1649-029, Lisbon, Portugal.
authors.forename: Osvaldo
authors.initials: O
authors.lastname: Santos
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000523:psychology*; D011594:Psychometrics; D011788:Quality of Life / Q000523:psychology*; D015203:Reproducibility of Results; D012649:Self Concept; D013315:Stress, Psychological / Q000523:psychology; D063189:Symptom Assessment; D055815:Young Adult
keywords: Health-related quality of life; ORWELL-R; Obesity; Validation