Development of a New Patient-Reported Outcome to Measure Fatigue in Patients with Multiple Sclerosis

Area of Science:

• Neurology
• Psychology
• Rehabilitation

Background:

• Fatigue is a prevalent and disabling symptom in multiple sclerosis (MS), affecting up to 80% of patients.
• Current fatigue assessment tools for MS lack conceptual clarity or are too lengthy for routine clinical use.

Purpose of the Study:

• To develop and evaluate a new patient-reported outcome instrument for assessing multidimensional fatigue domains in MS patients.
• The instrument is designed for practical application in clinical practice.

Main Methods:

• Qualitative interviews (n=19) identified core fatigue domains.
• Cognitive interviews (n=50) ensured item relevance and clarity.
• Exploratory factor analysis and internal consistency testing (Cronbach's alpha) validated the instrument's structure and reliability.

Main Results:

• The 14-item instrument identifies three fatigue subdomains: Psychosocial, Physical, and Cognitive.
• Exploratory factor analysis supported a three-factor solution, explaining 75% of the variance.
• High internal consistency was found for all factors: Psychosocial (α=0.923), Physical (α=0.895), and Cognitive (α=0.844).

Conclusions:

• The new instrument is conceptually robust, capturing the multifaceted nature of MS fatigue.
• Initial findings support the instrument's internal structure and conceptual foundation.
• It provides a practical tool for monitoring fatigue symptoms in neurological consultations for MS patients.