What constructs are represented in multiple sclerosis specific health-related quality of life measures

Health-related quality of life (HRQL) is becoming a common outcome for many medical and rehabilitative studies. This is specifically true for multiple sclerosis (MS), one of the most common chronic neurological condition affecting young adults. As MS results in severe consequences, its management depends on careful assessment of the outcome of interest. Measures of HRQL should represent all domains of HRQL and should be based on a theoretical frame of reference.;The main objective of this content analysis study is to estimate the extent to which items in the MS-specific HRQL measures capture all domains of HRQL, using the International Classification of Functioning Disability and Health (ICF) and the Wilson-Cleary models as frames of reference. Items of 10 HRQL measures were linked to the ICF by a pool of 25 health professionals using a standardized procedure. Among the 550 items that were mapped, 44% represented symptoms, 34% represented functioning and 35% represented concepts of general health perception and satisfaction with quality of life. Only 6% of the items targeted environmental factors. Measures differed not only in the degree of representing the different components of HRQL but also in the ways of ascertaining a single construct, fatigue, one of the most distressing MS symptom.