Assessing disability in morbidly obese individuals: the Italian Society of Obesity test for obesity-related disabilities

PURPOSE: To validate a new obesity-specific disability assessment test: the Obesity-related Disability test (Test SIO Disabilità Obesità Correlata, TSD-OC). METHODS: Adult obese individuals were assessed with the TSD-OC, 36-Item Short-Form Health Survey (SF-36), 6-min walking test (6MWT) and grip strength. The TSD-OC is composed of 36 items divided into seven sections (pain, stiffness, activities of daily living and indoor mobility, housework, outdoor activities, occupational activities and social life). Statistical correlations between the TSD-OC, functional assessment (6MWT and grip strength) and quality of life parameters (SF-36) were analysed. Internal consistency was assessed with Cronbach's α test. Test-retest reliability was evaluated in a subgroup of 30 individuals. A linking exercise between TSD-OC items and categories of the International Classification of Functioning, Disability and Health was performed. RESULTS: Test-retest showed excellent stability (r = 0.90) and excellent internal consistency was reported (Cronbach's α > 0.90). Significant low to moderate correlations between TSD-OC, SF-36 scores, 6MWT and grip strength were observed. A total of 26 ICF categories were linked, mostly related to the area of mobility. CONCLUSIONS: The TSD-OC is a reliable and valid instrument for measuring self-reported disability in obese subjects. It may represent an important tool for establishing rehabilitation needs in individuals with obesity-related disability, for planning appropriate rehabilitation programmes and for evaluating their effectiveness.