Assessing quality of life in severe obesity: development and psychometric properties of the ORWELL-R

Purpose: 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.