Mills RJ, Young CA, Pallant JF et al.
Walton Centre for Neurology and Neurosurgery, Liverpool, UK.
J Neurol Neurosurg Psychiatry 2010;81:1049–51.
Editor’s note: Fatigue is a common symptom in multiple sclerosis (MS) and is often measured using the 21-item Modified Fatigue Impact Scale (MFIS). In the current article, Mills and colleagues analyzed the results of the MFIS, completed by 415 UK patients with MS, using the Rasch model, which allows ordinal observations of clinical phenomena to be converted into linear measurement.