Association between Disability, Cognition, Fatigue, EQ-5D-3L Domains, and Utilities Estimated with Different Western European Value Sets in Patients with Multiple Sclerosis.

OBJECTIVES: To assess the association between fatigue, cognition, domains of the EuroQol five-dimensional questionnaire (EQ-5D-3L), disability, and utilities estimated with several Western European value sets in patients with multiple sclerosis (MS).

METHODS: Data from a multinational, cross-sectional, observational study of patients with MS (N = 16,808) conducted in 16 European countries were used. Health-related quality of life data were collected through the EQ-5D-3L, and fatigue and cognitive difficulties were self-assessed on a 10-point visual analogue scale. Associations were assessed using Pearson correlation and multivariate regression model.

RESULTS: Symptoms of fatigue and cognitive difficulties were present in 90% and 70% of patients at all levels of disability, respectively, and thus only weakly correlated to disability. Problems in the EQ-5D-3L domains were common even at mild disability levels. Mobility, usual activities, and pain issues were experienced by 80% to 90% of patients with moderate and high levels of disability. Mobility, usual activities, and self-care were strongly correlated to disability. Disability, MS type, fatigue, and cognition were associated with utility in regression models, although the coefficients of fatigue and cognition were small.

CONCLUSIONS: The strong relationship of disability with utility was confirmed. Despite this, fatigue and cognitive difficulties were associated with utility estimated with different European value sets.