Multiple Sclerosis Functional Composite (MSFC)
The MSFC is a three-part, standardized, quantitative, assessment instrument for use in clinical studies, particularly clinical trials, of MS. (Cutter et al, 1999) It was developed by a special Task Force on Clinical Outcomes Assessment that had been appointed by the National Multiple Sclerosis Society’s Advisory Committee on Clinical Trials of New Agents in Multiple Sclerosis. (Whitaker et al, 1995; Rudick et al, 1996) It was the consensus of the task force that important clinical dimensions not emphasized in existing rating scales, e.g. cognition, should be measured. The MSFC was designed to fulfill three criteria:
- It should be multidimensional to reflect the varied clinical expression of MS across patients and over time
- The dimensions should change relatively independently over time
- One component should be a measure of cognitive function. The three components of the MSFC measure leg function/ambulation, arm/hand function, and cognitive function.
Administration time will vary depending upon the ability of the patient. Total administration time for all three measures should be approximately 20-30 minutes.
The MSFC measures are administered in person by a trained examiner. The examiner need not be a physician or nurse.
The MSFC can produce scores for each of the three individual measures as well as a composite score. In addition, there are a variety of ways to calculate scores depending on the nature of the study and sample.
The three component measures of the MSFC had been used for some time in MS prior to their being combined into a composite measure. Analysis of data from studies using these measures had pointed to their reliability, validity, and sensitivity. As a set of objective, quantitative assessment instruments, the MSFC represents a methodological advance over the ordinal clinical rating scales that have been used in MS in the past, e.g., the EDSS and Ambulation Index. A three-part instrument offering both separate and composite scores, the MSFC provides a versatile assessment method for investigational purposes with the ability to measure patients at various levels of disability, i.e., ambulation at less disabled levels of the EDSS, arm function at more disabled levels, and cognitive function at all levels. Since its introduction, the MSFC has seen increasing use in both clinical trials and other clinical studies.
All three measures making up the MSFC have been shown to have good inter-rater and test-retest reliability. In addition, there is considerable evidence for their validity and sensitivity to clinically relevant change in MS patients. However, performance on the MSFC is sensitive to practice effects, that is, patients often display poorer performance when first tested due to lack of familiarity with the tasks. It is recommended that three or four administrations be given prior to a baseline assessment if accurate (rather than comparative) assessments of change over time are needed. Refer to the discussion of the individual components of the MSFC for further details concerning their psychometric properties.