Change in clinician-assessed measures of multiple sclerosis and subject-reported quality of life: results from the IMPACT study

Abstract

Background: The IMPACT study demonstrated the benefit of interferon beta-1a (IFNbeta-1a, Avonex) two-year change in disability measured by the Multiple Sclerosis Functional Composite (MSFC) in secondary progressive multiple sclerosis (SP-MS) and health-related quality of life (HRQoL) measured by the Multiple Sclerosis Quality of Life Inventory (MSQLI). The IMPACT data permit a detailed assessment of the relation between clinical and self-reported measures.

Methods: IMPACT was an international randomized, double-blind, placebo-controlled trial of SP-MS patients. As the MSQLI is only in English, this report includes US and Canadian subjects. Subjects were randomized to weekly intramuscular (im) injections of INbeta-1a (60 microg) or placebo for 24 months.

Results: At baseline and follow-up, MSQLI correlations were generally stronger with the EDSS than with the MSQLI, MSFC but comparable with MSFC components. Combining the two groups, MSQLI changes for those in the best and worst MSFC change quartiles demonstrated a statistical difference for six of the 11 MSQLI scales. Linear regression demonstrated that EDSS change from baseline to month-24 scores was correlated with change in two MSQLI components.

Conclusion: These data support the appropriateness of using the MSQLI with individuals who have SP-MS.