Background: Evidence on the progress of disease severity in multiple sclerosis (MS) is generally limited in scope.
Objectives: To examine the course of a broad spectrum of MS-related disabilities and quality of life (QOL) in relation to disease severity, and responsiveness of the Multiple Sclerosis Impact Profile (MSIP).
Methods: The mortality rate was calculated after checking the national population register for vital status of the initial cohort. We performed a longitudinal study among 245 patients with MS attending the Groningen MS Center in the Netherlands. We assessed these patients in 2004 and 2009 using a postal survey including the MSIP to evaluate disabilities, the World Health Organization Quality of Life-Abbreviation version (WHOQOL-BREF) to evaluate QOL, and the ambulation question of the Expanded Disability Status Scale (EDSS) to evaluate disease severity. Responsiveness of the MSIP was estimated using standardized response mean (SRM).
Results: Increase of disability in the MSIP disability domains and loss of QOL were most prevalent and pronounced in patients with EDSS 0 to < 4.5 in 2004. MSIP and QOL scores were remarkably stable in the higher disease severity groups. Mortality rates were highest (24%) in patients with EDSS ≥ 7 to < 10 in 2004. SRM indices for the MSIP ranged between 0.26 and 0.56.
Conclusions: Prominent increases in multiple aspects of disability and loss of QOL occur especially in the early stages in MS. Health care interventions may lead to health and QOL gains, in particular when offered to patients in the first stage of the MS process. Responsiveness was sufficient for nine of the 11 MSIP domains.