[Psychometric Properties of a New Instrument for Evaluating Quality of Life, the WHOQOL-26, in a Population of Patients with Neuromuscular Diseases]

This study describes the principal psychometric properties of the French version of the WHOQOL-26, a short version (26 questions) of the WHOQOL-100, which are World Health Organization instruments for evaluation of quality of life (QOL) which include four dimensions (physical, psychological, environmental, social relations). The use of this tool with psychiatric patients is discussed. Collection of data was performed during a national inquiry on persons with neuromuscular disorders. The population included 2,102 subjects (mean age 42.9 +/- 15 years). Ten different clinical entities were represented, which differed in the type of lesion of the motor unit, the permanence and localization of the loss of muscle strength, the progression of the respiratory deficit, the moment of its occurrence and seriousness of prognosis. This questionnaire was well-adapted to the study population (weak effect of extremes) and was well-accepted (only 5% non-responses). Compared with the long version, homogeneity is less pronounced, but remains acceptable (the item-scale correlation is superior to 0.40 for 66.7% of some items), which is the same as the reliability (Cronbach's alpha coefficient always over 0.65). The sensitivity in relation to the diagnosis is verified for all four dimensions (p = 0.05). The concurrent validity, studied using general QOL evaluation scores, satisfaction with health, and the importance of repercussions of incapacities on daily life was also globally demonstrated (p < 0.0001).