Fatigue Severity Scale – FSS
A 9-item self-report instrument designed to measure the severity of fatigue and its impact on daily functioning.
Scale Development & Technical Details
Scale Overview
The Fatigue Severity Scale – FSS was developed by Krupp LB, LaRocca NG, Muir-Nash J, Steinberg AD (1989). It is designed to measure Fatigue severity. The scale is intended for use with Adults, clinical populations (e.g., Multiple Sclerosis, Systemic Lupus Erythematosus).
Scale Structure
This instrument consists of 9 items.
Response Format
Respondents rate each item using a 7-point Likert scale (1 = Strongly Disagree to 7 = Strongly Agree).
Scoring
Item scores are averaged to produce a mean score.
Total scores range from 1 to 7. Interpretation guidelines:
- Normal/Borderline Fatigue: 1 – 3
- Severe Fatigue: 4 – 7
Psychometric Properties
Internal Consistency: The scale has demonstrated good to excellent internal consistency with reported Cronbach’s alpha values of 0.89.
Administration
The scale is self-administered and typically takes approximately 5 minutes to complete. It can be administered individually or in group settings. No special training is required for administration.