Measuring fatigue in Multiple Sclerosis - The Modified Fatigue Impact Scale

[Sly Saint]

Description
The MFIS is a modified form of the Fatigue Impact Scale (Fisk et al, 1994b) based on items derived from interviews with MS patients concerning how fatigue impacts their lives. This instrument provides an assessment of the effects of fatigue in terms of physical, cognitive, and psychosocial functioning. The full-length MFIS consists of 21 items while the abbreviated version has 5 items. The abbreviated version can be used if time is limited but the full-length version has the advantage of generating subscales. The MFIS is one of the components of the MSQLI.

Download the MSQLI: A User’s Manual (PDF)

https://www.nationalmssociety.org/F...Measures/Modified-Fatigue-Impact-Scale-(MFIS)


Fatigue Impact Scale (Fisk et al, 1994b)

Abstract
The fatigue impact scale (FIS) was developed to improve our understanding of the effects of fatigue on quality of life. The FIS examines patients' perceptions of the functional limitations that fatigue has caused over the past month. FIS items reflect perceived impact on cognitive, physical, and psychosocial functioning. This study compared 145 patients referred for investigation of chronic fatigue (ChF) with 105 patients with multiple sclerosis (MS) and 34 patients with mild hypertension (HT). Internal consistency for the FIS and its three subscales was >.87 for all analyses. Fatigue impact was highest for the ChF group although the MS group's reported fatigue also exceeded that of the HT group. Discriminant function analysis correctly classified 80.0% of the ChF group and 78.1% of the MS group when these groups were compared. This initial validation study indicates that the FIS has considerable merit as a measure of patients' attribution of functional limitations to symptoms of fatigue.

https://academic.oup.com/cid/article-abstract/18/Supplement_1/S79/317047

another paper that is cited as showing that this scale can differentiate between CFS patients and MS patients...yet it says "This study compared 145 patients referred for investigation of chronic fatigue (ChF)".

http://sci-hub.tw/https://doi.org/10.1093/clinids/18.Supplement_1.S79

see also article in Occupational Medicine

Discussion
I find the MFIS-5 useful in quantifying fatigue symptoms in patients with MS. I have also found it useful in my assessment of patients with other conditions in which fatigue is a dominant symptom, e.g. cancer, stroke and chronic fatigue syndrome—as an adjunct and always with the caveat that the questionnaire has been primarily validated for use in patients with MS.

https://academic.oup.com/occmed/article/66/3/256/2750552