This Modified Fatigue Impact Scale (MFIS) calculator evaluates fatigue related effects on life quality in patients suffering from multiple sclerosis. Below the form there is more information on the two available versions of the scale and on the study it has been based on.

1I have been less alert.
2I have had difficulty paying attention.
3I have been unable to think clearly.
4I have been clumsy and uncoordinated.
5I have been forgetful.
6I have had to pace myself in my physical activities.
7I have been less motivated to do anything that requires physical effort.
8I have been less motivated to participate in social activities.
9I have been limited in my ability to do things away from home.
10I have had trouble maintaining physical effort for long periods.
11I have had difficulty making decisions.
12I have been less motivated to do anything that requires thinking.
13My muscles have felt weak.
14I have been physically uncomfortable.
15I have had trouble finishing tasks that require thinking.
16I have had difficulty organizing things.
17I have been less able to complete tasks that require physical effort.
18My thinking has been slowed down.
19I have had trouble concentrating.
20I have limited my physical activities.
21I have needed to rest more often or for longer periods of time.
! The shortened version of the MFIS uses questions 1, 9, 10, 17, and 19 from the longer version of the MFIS.
1I have been less alert.
9I have been limited in my ability to do things away from home.
10I have had trouble maintaining physical effort for long periods.
17I have been less able to complete tasks that require physical effort.
19I have had trouble concentrating.

How does this Modified Fatigue Impact Scale (MFIS) calculator work?

This health tool is the modified form of the Fatigue Impact Scale that incorporates items deducted as relevant from interviews with MS patients on how fatigue symptoms affect the quality of their lives.

MFIS assesses fatigue effects in three dimensions:

■ Physical;

■ Cognitive;

■ Psychosocial.

It comprises of 21 items in the full version that can be found in tab 1 of this MFIS calculator and 5 items in the shortened version available in tab 2.

The shortened/ abbreviated version is often used when time limitations exist but unlike the full scale, doesn’t generate subscales, therefore isn’t as specific.

Both version are self-report and very easy to administer and take 5 to 10 minutes (full version) and 2 to 3 minutes (short version). If necessary, the scale can be administered as an interview as well with minimal training.

MFIS is one of the assessment tools in the Multiple Sclerosis Quality of Life Inventory (MSQLI).

The scale focuses on how multiple sclerosis symptoms, specifically fatigue, affect everyday life while the use of subscales can generate further insight in the specific areas of functioning.

One of the criticisms received by this model is that the subscales often correlate with each other and limit the usefulness of the evaluation.

In the original study, 90% of the 309 subjects have identified fatigue as "tiredness or the need to rest" and in 48% of the subjects, fatigue increased the perceived severity of other MS symptoms.

Fatigue daily occurrence was evidenced in more than 66% of the subjects with periodicity in the late afternoon and evening.

Fatigue relieving strategies such as a planned daily schedule of activity and rest had been rated as partially effective for the majority of subjects studied.

Most MS scales, such as the Modified Ashworth Scale or the Beighton Score correlate with each other because of similar construct but unlike most scales, MFIS tends to evaluate better the cognitive and psychological functioning.

MFIS score interpretation

Each of the items is based on an ordinal scale with answers graded from 0 to 4:

■ Never (0 points);

■ Rarely (1 point);

■ Sometimes (2 points);

■ Often (3 points);

■ Almost Always (4 points).

Therefore the total maximum score is 84 points in the 21 item full version and 20 points in the short 5 item version.

In the full version, three individual subscales can be generated by summing answer points from specific items:

■ Physical functioning (out of 36 points): items 4, 6, 7, 10, 13, 14, 17, 20, 21;

■ Cognitive functioning (out of 40 points): items 1, 2, 3, 5, 11, 12, 15, 16, 18, 19;

■ Psychosocial functioning (out of 8 points): items 8, 9.

The smallest detectable chance is 16.2 while the minimal detectable change (MDC) is 19.3%.

There isn’t a specific grading of the results or any functioning cut offs and the quantification of fatigue severity impact in patients with multiple sclerosis remaining to clinicians. The scale is very useful for the longitudinal tracking of MS related fatigue.

However, another criticism is that the score interpretation lacks objective anchors and although it shows when the score changed and in what direction, it doesn’t provide enough guidance on what those changes mean in practice.


1) Freal JE, Kraft GH, Coryell JK. (1984) Symptomatic fatigue in multiple sclerosis. Arch Phys Med Rehabil; 65(3):135-8.

2) Téllez N, Río J, Tintoré M, Nos C, Galán I, Montalban X. (2005) Does the Modified Fatigue Impact Scale offer a more comprehensive assessment of fatigue in MS? Mult Scler; 11(2):198-202.

3) Ritvo PG, Fischer JS, Miller DM, Andrews H, Paty DW, LaRocca NG. (1997) MSQLI Multiple Sclerosis Quality of Life Inventory: A User's Manual. The Consortium of Multiple Sclerosis Centers Health Services Research Subcommittee.

4) Larson RD. (2013) Psychometric Properties of the Modified Fatigue Impact Scale. Int J MS Care; 15(1): 15–20.

5) Braley TJ, Chervin RD. (2010) Fatigue in Multiple Sclerosis: Mechanisms, Evaluation, and Treatment. Sleep; 33(8): 1061–1067.

22 May, 2016