Background: Obesity is associated to increased risk of metabolic comorbidity as well as increased mortality. Notably, obesity is also associated to the impairment of the psychological status and of quality of life. Only three questionnaires are available in the Italian language evaluating the health-related quality of life in subjects with obesity. The aim of the present study was to test the validity and reliability of the Italian version of the Laval Questionnaire.
Methods: The original French version was translated into Italian and back-translated by a French native speaker. 273 subjects with obesity (Body Mass Index ≥ 30 kg/m2) were enrolled; the Italian version of the Laval Questionnaire and the O.R.Well-97 questionnaire were administered in order to assess health- related quality of life. The Laval questionnaire consists of 44 items distributed in 6 domains (symptoms, activity/mobility, personal hygiene/clothing, emotions, social interaction, sexual life). Disability and overall psychopathology levels were assessed through the TSD-OC test (SIO test for obesity correlated disabilities) and the SCL-90 (Symptom Checklist-90) questionnaire, respectively. To verify the validity of the Italian version, the analysis of internal consistency, test-retest reliability, and construct validity were performed.
Results: The observed proportion of agreement concordance of results was 50.2% with Cohen's K = 0.336 (CI 95%: 0.267-0.404), indicating a fair agreement between the two tests. Test-retest correlation was statistically significant (ρ = 0.82; p < 0.01); validity (standardized Chronbach's alpha) was considered reliable (α > 0.70). The analysis of construct validity showed a statistically significant association in terms of both total score (ρ = -0.66) and scores at each single domain (p < 0.01). A high correlation (p < 0.01) was observed between Laval questionnaire total and single domain scores and other related measures (Body Mass Index, TSD-OC scores, SCL-90 global severity index), revealing a high construct validity of the test.
Conclusions: The Italian version of the Laval Questionnaire is a valid and reliable measure to assess the health-related quality of life in subjects with obesity.
Keywords: Obesity; Quality of life.