The Multiple Sclerosis Functional Composite A clinically meaningful measure of disability

Background: The Multiple Sclerosis Functional Composite (MSFC) provides a focused and sensitive evaluation of disability in patients with multiple sclerosis ( MS) that may be more responsive to change than that provided by the Expanded Disability Status Scale. Expert Clinical Opinion: The MSFC is a 3-part quantitative instrument that measures arm, leg, and cognitive function with the 9-Hole Peg Test (arm/hand dexterity), the Timed 25-Foot Walk ( leg function), and the Paced Auditory Serial Addition Test (3-second version, PASAT3; cognition). The MSFC has excellent test-retest reliability. Construct validity was supported by expected differences in scores between patients with primary or secondary progressive MS compared with relapsing-remitting MS. Concurrent validity was demonstrated by significant correlations with the Expanded Disability Status Scale, the Sickness Impact Profile, and the Short Form-36, particularly on the physical components of the latter 2 scales. MSFC scores also correlate with MRI changes. Limitations of the MSFC include practice effects with the PASAT and to a lesser extent the 9-Hole Peg Test, variations in the reference populations used to calculate Z-scores, and the lack of an accepted definition of a clinically meaningful change. Future Directions: Future research should be directed at adding a test that measures visual function ( e. g., contrast acuity), at replacing the PASAT by a cognition test that has better measurement characteristics, and at developing methods to better understand the clinical relevance of changes in MSFC scores. NEUROLOGY 2010; 74(Suppl 3): S8-S15