Objective: To prospectively characterize the relation between 1-year changes in neurologist ratings of abnormalities as measured by means of the Expanded Disability Status Scale (EDSS) and changes in observations of functional impairment as measured by means of the Multiple Sclerosis Functional Composite (MSFC) in the clinical assessment of multiple sclerosis (MS).
Methods: One hundred twenty patients with MS were recruited at our outpatient clinic. Impairment and disability at baseline and follow-up were assessed using the EDSS and MSFC. We studied correlations between change (Delta) in the EDSS, MSFC, and MSFC components for the total population and different subgroups and analyzed the contribution of change in MSFC components to change in the EDSS and MSFC.
Results: Median EDSS score at baseline was 4.5; at follow-up, 5.0. Mean MSFC score at baseline was -0.00; at follow-up, -0.04. Good cross-sectional correlations were found between the EDSS and MSFC at baseline (-0.72) and follow-up (-0.73). Only weak correlations were found between DeltaEDSS and DeltaMSFC. Although DeltaEDSS showed the strongest correlations with change in leg function and weak or no correlation with change in cognitive function or arm function, DeltaMSFC showed the highest correlation with change in arm function and cognitive function.
Conclusion: Our longitudinal data indicate that the MSFC reflects change from different dimensions of neurologic functions, which is a favorable characteristic when compared with the EDSS.