"Specific" scale compared with "generic" scale: a double measurement of the quality of life in a French community sample of obese subjects.
STUDY OBJECTIVE: To determine the aspects of quality of life that are affected by weight in the general population, to develop a specific questionnaire (OSQOL) that can measure with reliability and validity the impact of overweight and obesity on well being, and to compare the results with those obtained using a well known generic tool (the "SF 36" scale). DESIGN: Cross sectional survey with matched control group. SETTING: Community. PATIENTS: A permanent survey base of approximately 10,000 representative ordinary households were screened for weight and height. Five hundred subjects were randomly drawn from the sub-sample of adult people with a body mass index equal or greater than 27. A control sample of 500 subjects matched for sex, age, and employment status was drawn from the non-obese population. MAIN RESULTS: A short specific Quality Of Life scale, the OSQOL, was produced that comprises 11 items belonging to four independent dimensions. Using this scale and the SF36, it was found that: (1) moderately obese subjects (27 < or = BMI < 30) did not significantly differ from the control group except for physical capacity; (2) in the group of obese subjects with a BMI > 30, quality of life seemed to be impaired for five of nine dimensions of the SF36 compared with the control population, all related to physical consequences of obesity. This population essentially perceived itself in terms of poor general health. (3) No significant difference was observed between the samples for the psychological and social dimensions of the SF36. CONCLUSION: The quality of life of patients with severe obesity is impaired, but it mainly affects the physical consequences of the disease. The psychological and social repercussions that could have been expected to affect this population were not demonstrated. The hypothesis of a process of adaptation of the person and their social environment cannot therefore be excluded. Methodologically, comparison of the specific OSQOL with the generic SF3 shows clearly that the two kinds of scales correspond to different objectives and should be considered as complementary.