Skip to main content

Rehab Measures: Fatigue Severity Scale

Link to instrument

Measure available at Manchester Osteopathic (other languages available below) 

Title of Assessment

Fatigue Severity Scale 



Instrument Reviewer(s)

Initially reviewed by Avisha Shah in 10/2012; Updated by Terry Ellis, PT, PhD, NCS and Laura Savella SPT in 2013.

Summary Date



The 9-item scale which measures the severity of fatigue and its effect on a person's activities and lifestyle in patients with a variety of disorders.


  • A 9 item questionnaire with questions related to how fatigue interferes with certain activities and rates its severity.
  • The items are scored on a 7 point scale with 1 = strongly disagree and 7= strongly agree.
  • The minimum score = 9 and maximum score possible = 63. Higher the score = greater fatigue severity.
  • Another way of scoring: mean of all the scores with minimum score being 1 and maximum score being 7.
  • Self report scale.

Area of Assessment


Body Part


ICF Domain

Activity; Participation 



Assessment Type


Length of Test

05 Minutes or Less 

Time to Administer

Less than 5 minutes

Number of Items

9 items 

Equipment Required

  • Pen

Training Required

No training required

Type of training required

No Training 



Actual Cost

No cost for administering the scale.

Age Range


Administration Mode



Arthritis; Fibromyalgia; Geriatrics; Multiple Sclerosis; Parkinson’s Disease; Stroke 

Populations Tested

  • Cancer
  • Elderly Population
  • Fibromyalgia
  • Lyme’s Disease
  • Multiple Sclerosis
  • Parkinson’s Disease
  • People with major depression
  • Post Polio Patients
  • Rheumatoid Arthritis
  • Stroke
  • Systemic Lupus Erythematosus

Standard Error of Measurement (SEM)

Not Established

Minimal Detectable Change (MDC)

Not Established

Minimally Clinically Important Difference (MCID)

Not Established

Cut-Off Scores

Multiple Sclerosis and Systemic Lupus Erthymatosus:

(Krupp et al, 1989; n = 74, mean age = 40.2 years)

  • The cut-off score is 36 where a score > 36 may indicate severe fatigue or need for further evaluation.

Normative Data

Healthy Population:

(Grace et al, 2006; n = 16, mean age = 69.94 years)

  • Mean (SD) FSS scores for healthy individuals; 2.3 (0.7)

Parkinson’s Disease:

(Hagell et al, 2006; n = 118, mean age = 63.9(9.6) years, mean time post PD = 8.4 (5.7) years)

  • Mean SD (FSS) score for PD patients; 3.9 (1.6), range 2.6-5.2

(Winward et al; n = 37; H&Y Stages 0 - 4; mean age = 64.1(8.17)

  • Mean FSS Score = 4.08 (1.46); FSS Scored 0 - 7

Test-retest Reliability

Parkinson's Disease:

(Valderramas et al, 2012; n = 30, mean age = 62 (11) years, mean time post- PD = 7.6 (6.5) years)

  • The evaluation of the FSS-BR (Fatigue Severity Scale-Brazilian-Portuguese version) suggests an excellent Test-retest reliability (ICC = 0.91)

Interrater/Intrarater Reliability

Not Established

Internal Consistency

Parkinson’s Disease:

(Hagell et al, 2006)

  • Excellent internal consistency (Cronbach’s alpha = 0.94)

(Grace et al, 2006)

  • Excellent split half reliability (Cronbach’s alpha = 0.86 and 0.91)
  • For 8 out of the 9 items, Adequate-Excellent (0.44-0.78) correlation was observed.
  • For item 2, Poor (0.27) correlation was seen.

Criterion Validity (Predictive/Concurrent)

Not Established

Construct Validity (Convergent/Discriminant)

Convergent Validity:

Parkinson’s Disease:

  • Excellent (r = -0.77) negative correlation with Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) scale (Hagell et al, 2006).
  • Excellent (r = 0.62) correlation with Nottingham Health Profile (NHP-EN) scale (Hagell et al, 2006).
  • Excellent (r = 0.84) correlation with Parkinson’s Fatigue (PFS) scale (Grace et al, 2006).
  • Poor-adequate (r = 0.22-0.47) correlation with Parkinson’s Disease Questionnaire-39 (PDQ-39) scale (Herlofson et al, 2003; n = 66, mean age = 70.8 (9.9) years, time since PD = 70.2 (56.1) months).
  • Adequate (r = 0.37) correlation with MOS-SF-36 scale (Herlofson et al, 2003).
  • Poor (r = 0.19) correlation with Hamilton Depression Rating (HAM-D) scale (Garber CE & Friedman JH, 2003; n = 37)
  • Excellent (r = 0.80) correlation with Fatigue rating Scale (Grace et al, 2006)
  • Poor-adequate (r = 0.22-0.47) correlation with Parkinson’s Disease Questionnaire-39 (PDQ-39) scale (Herlofson et al, 2003; n = 66, mean age = 70.8 (9.9) years, time since PD = 70.2 (56.1) months)
  • Excellent (r = 0.93) correlation of FSS-BR with PDQ-39 (Valderramas et al, 2012)
  • Excellent (r = 0.75) correlation of FSS-BR with Beck Depression Inventory (Valderramas et al, 2012)
  • Adequate (r = 0.40) correlation of FSS-BR with Hoehn & Yahr scale (Valderramas et al, 2012)
  • Adequate (r = 0.45) correlation of the FSS-BR with UPDRS (Valderramas et al, 2012)
  • Adequate (r = 0.37) correlation with MOS-SF-36 scale (Herlofson et al, 2003)
  • Poor (r = 0.19) correlation with Hamilton Depression Rating (HAM-D) scale (Garber CE & Friedman JH, 2003; n = 37)
  • Excellent (r = 0.80) correlation with Fatigue rating Scale (Grace et al, 2006)
  • Poor (r = -0.184) correlation of FSS with 6 minute walk test (Garber CE & Friedman JH, 2003)

Content Validity

Not Established

Face Validity

Not Established

Floor/Ceiling Effects

Parkinson’s Disease:

(Hagell et al, 2006)

  • The Floor/Ceiling effects were adequate (2.5%) for a sample of PD patients.


Parkinson’s Disease:

Responsiveness to Pharmocological Intervention Mendoca et al, 2007; n = 17 treatment arm, receiving methyphenidate; mean age = 62.2(10), mean H&Y Stage = 2.58(0.5); n = 19 placebo arm, mean age = 66.3(7.6), mean H&Y Stage = 2.38(0.3)

  • Those persons in the treatment arm had a significant (p < 0.04) reduction in FSS Score by 6.5 points (from FSS = 43.8 at baseline); Cohen’s d = 0.79
  • Smaller reductions in the placebo group did not reach levels of significance Response to Exercise Intervention: Winward et al, 2010; H&Y 0-4. n = 20 exercise group, mean age = 63.4(6.7); n = 19 control group, mean age = 64.9(9.6)
  • No significant difference in score reduction between exercise and control group at 12 weeks

Professional Association Recommendations

Recommendations for use of the instrument from the Neurology Section of the American Physical Therapy Association’s Multiple Sclerosis Taskforce (MSEDGE), Parkinson’s Taskforce (PD EDGE), Spinal Cord Injury Taskforce (PD EDGE), Stroke Taskforce (StrokEDGE), Traumatic Brain Injury Taskforce (TBI EDGE), and Vestibular Taskforce (VEDGE) are listed below. These recommendations were developed by a panel of research and clinical experts using a modified Delphi process.


For detailed information about how recommendations were made, please visit:




Highly Recommend




Reasonable to use, but limited study in target group  / Unable to Recommend


Not Recommended


Recommendations Based on Parkinson Disease Hoehn and Yahr stage:














Recommendations for entry-level physical therapy education and use in research:


Students should learn to administer this tool? (Y/N)

Students should be exposed to tool? (Y/N)

Appropriate for use in intervention research studies? (Y/N)

Is additional research warranted for this tool (Y/N)





Not reported


Parkinson’s Disease:

  • At this point no studies report psychometrics in a sample of patients in H&Y Stage 5 and only one study includes pts in H&Y Stage 4
  • In a study examining the effects of exercise on fatigue in persons with PD (H&Y Stages 0-4), no significant changes were observed in FSS scores, questioning its responsiveness to change in an exercise intervention.
  • The FSS can be used to distinguish between fatigued and non-fatigued people with PD. (Hagell et al, 2006)
  • The scale has been studied and evaluated for psychometrics in multiple sclerosis patients. Limited psychometric evaluation has been done in PD population. Further, research on FSS should be performed for patients with PD
  • The FSS is widely used as it is concise and easy to administer. But it is a little vague as it is subjective in nature & does not provide a precise definition of fatigue
  • It can be used as a good screening tool as it can easily distinguish between fatigued and non-fatigued people. Therefore, it is important that the FSS is adequately researched in PD population

Fatigue Severity Scale translations:




Spanish (p4):


These translations, and links to them, are subject to the Terms and Conditions of Use of the Rehab Measures Database. RIC is not responsible for and does not endorse the content, products or services of any third-party website, and does not make any representations regarding its quality, content or accuracy. If you would like to contribute a language translation to the RMD, please contact us at

Do you see an error or have a suggestion for this instrument summary? Please e-mail us!


Garber, C. E. and Friedman, J. H. (2003). "Effects of fatigue on physical activity and function in patients with Parkinson's disease." Neurology 60(7): 1119-1124. Find it on PubMed

Grace, J., Mendelsohn, A., et al. (2007). "A comparison of fatigue measures in Parkinson's disease." Parkinsonism Relat Disord 13(7): 443-445. Find it on PubMed

Hagell, P., Hoglund, A., et al. (2006). "Measuring fatigue in Parkinson's disease: a psychometric study of two brief generic fatigue questionnaires." J Pain Symptom Manage 32(5): 420-432. Find it on PubMed

Herlofson, K. and Larsen, J. P. (2003). "The influence of fatigue on health-related quality of life in patients with Parkinson's disease." Acta Neurol Scand 107(1): 1-6. Find it on PubMed

Krupp, L. B., LaRocca, N. G., et al. (1989). "The fatigue severity scale. Application to patients with multiple sclerosis and systemic lupus erythematosus." Arch Neurol 46(10): 1121-1123. Find it on PubMed

Valderramas, S., Feres, A. C., et al. (2012). "Reliability and validity study of a Brazilian-Portuguese version of the fatigue severity scale in Parkinson's disease patients." Arq Neuropsiquiatr 70(7): 497-500. Find it on PubMed

Year published


Instrument in PDF Format

Approval Status Approved 
Created at 2/1/2013 1:34 PM  by Jason Raad 
Last modified at 2/11/2015 2:24 PM  by Jason Raad