The FSS has well-established reliability and validity for use with persons with MS.44 The FSS score is reported as one total score which is the mean of the nine items. Scores range from 1 to 7 and higher scores indicate greater impact of fatigue on daily life. The Modified Fatigue Impact Scale (MFIS) is also used to assess the impact of fatigue in terms of physical, cognitive and psychosocial functioning. Participants are asked to score 21 items, using a 5-item Likert scale, on how often fatigue affected them in the past 4 weeks.