Functional disability in France and its relationship with health-related quality of life : a population-based prevalence study

Objective To estimate the prevalence of functional disability in France and assess its association with the health-related quality of life (HRQoL). Methods Each member in 8,000 households randomly selected in the Lorraine population were mailed a questionnaire asking about their sociodemographic characteristics; the presence of chronic locomotor or non-rheumatic diseases; functional disability on the Health Assessment Questionnaire (HAQ); and HRQoL on the Duke Health Profile. The prevalence of functional disability was described, and its relationship with HRQoL was assessed by logistic regression analysis. Results Among the 6,148 subjects who responded (mean age 46 years ± 18.3, 48% men), the prevalence of moderate (HAQ ≥ 1) and severe (HAQ ≥ 2) functional disability, adjusted for age and sex, was 6.5% and 1.6% respectively. HRQoL was significantly low in all dimensions for subjects with severe functional disability. Functional disability of locomotor origin significantly affected the physical (OR = 10.6 [5.1-22.1]), mental (OR = 4.4 [2.5-7.8]), and social (OR = 2.4 [1.4-4.3]) dimensions, with a threshold effect according to the disability level and perceived health (OR= 10.6 [5.8-19.4]), with a cause-effect relationship. Conclusion The prevalence of reported (i.e., not observed) functional disability in terms of its impact on HRQoL helps physicians to better understand its differential consequences, which should ease patient dependence, facilitate the analysis of health care needs and the development of prevention measures, and improve the HRQoL of patients and their families.