Abstract General Information

Title

IS THE MODIFIED FATIGUE IMPACT SCALE APPLIED BY TELEPHONE IN INDIVIDUALS WITH MULTIPLE SCLEROSIS VALID AND RELIABLE? An investigation of measurement properties

Abstract

Introduction: Individuals with multiple sclerosis (MS) commonly have fatigue. It is necessary to understand the perceived impacts of fatigue on the daily lives of these individuals. Going to a clinic can limit the assessment process, and the telephone can be an alternative.

Objective: To investigate the concurrent criterion validity and test-retest reliability of the Modified Fatigue Impact Scale (MFIS) administered by telephone to individuals with MS.

Methods: This is a methodological study (CAAE 57417322.8.0000.5134). Individuals (age ≥18 years) and diagnosis of MS confirmed by a neurologist were recruited. The MFIS, comprising three domains, was administered face-to-face and by telephone to establish concurrent criterion validity. After 5-7 days, the MFIS was performed a second time over the telephone to investigate test-retest reliability. The intraclass correlation coefficient (ICC) with a 95% confidence interval (CI) was used.

Results: 30 individuals (40.5±10.6 years) were included, most of them female (n=20, 66.7%) with a median score on the Expanded Disability Status Scale (EDSS) of 2.0±4.0. Between face-to-face and telephone application, a significant (p<0.001) and high-magnitude correlation was found for the total score (ICC=0.87, 95%CI=0.75-0.93), physical domain (ICC=0.85, CI95%=0.72-0.93), cognitive (ICC=0.88, CI95%=0.76-0.94) and psychosocial (ICC=0.70, CI95%=0.46- 0.84). Between telephone applications, a significant correlation (p<0.001) of very high magnitude was found for the total score (ICC=0.97, 95%CI=0.95-0.98), physical domain (ICC=0, 96, CI95%=0.92-0.98), cognitive (ICC=0.96, CI95%=0.93-0.98) and psychosocial (ICC=0.91, CI95%=0.83-0.96).

Conclusion: The MFIS applied by telephone showed adequate validity and reliability to assess the perception of the impact of fatigue in individuals with MS.