Fatigue Severity Scale (FSS)

The FSS was originally developed for use among individuals with Multiple Sclerosis (Krupp 1989). It captures the individual’s experience of mental or psychological fatigue and how it interferes with performing certain activities (exercise, work and family life).

Number of items: 9

Procedure/Administration: Self report scale. Participants choose the level of agreement for each question, from 1 = strongly disagree to 7 = strongly agree. Ratings are based on their experience of fatigue over the past seven days.

How scored: A total score is represented by the mean of all the answered items (adding up all the answers and dividing by nine).

Interpretability: Scores range from 1-7 with higher scores indicating higher levels of fatigue. Scores of 4 and over are indicative of significant fatigue in other populations.

Acceptability: Some of the items may not be reflective of the SCI condition. However, the FSS has been extensively validated in other populations and may be the most widely used measure of fatigue in neurologic disorders (Anton et al. 2008). The obvious problem with this measure is its subjectivity.

Languages: N/a

Usability: N/a

Time to administer: 5 minutes

Time to score: Quickly scored

Training required: N/a

Availability: A copy of the tool can be obtained at http://www.mult-sclerosis.org/fatigueseverityscale.html.

Equipment required: None

Summary:

  • The FSS might have difficulties distinguishing fatigue from depression (the influence of pain may influence scores on the FSS).
  • Can be used as a screen for fatigue in individuals with SCI. However, results should be interpreted with caution as some items may not have meaning for the SCI population.

Psychometric Summary

Reliability

Validity

Responsiveness

Results

Results

Results

Floor/ceiling

IC: Green light

TR: Green light 

 

Construct: Yellow light

AUC: Yellow light

SS: Yellow light  

N/a

N/a

Note: TR= Test re-test; IC= Internal Consistency; Inter-O= Inter-observer; Intra-O= Intra-observer; SS= Sensitivity/Specificity; AUC= Area under ROC curve; N/a= No information. 

Red light= A single study involving SCI subjects which has less than adequate findings of reliability, validity, and/or responsiveness.

Yellow light= A single study involving subjects with SCI which has adequate to excellent findings of reliability, validity, and/or responsiveness.

Green light= At least 2 studies involving subjects with SCI which have adequate to excellent findings of reliability, validity, and/or responsiveness.

References

  • Anton HA, Miller WC, Townson AF. Measuring fatigue in persons with spinal cord injury. Arch Phys Med Rehabil 2008; 89: 538-542.
  • Hammell KW , Miller WC, Forwell SJ, Forman BE, Jacobsen BA. Fatigue and spinal cord injury: a qualitative analysis Spinal Cord 2008; advance online publication 10 June 2008.
  • Krupp LB, LaRocca NG, Muir-Nash J, Steinbery AD. The fatigue severity scale. Application to patients with multiple sclerosis and systemic lupus erythematosus Arch Neurol. 1989; 46: 1121-3.