Chalder Fatigue Scale
Medafile - 21 point modification

       ID:         DATE:           TIME (24hr): 


INSTRUCTIONS: We would like to know more about any problems you have had with feeling tired, weak or lacking
in energy in the last month. Please answer ALL the questions by ticking the answer which applies to you most closely.
If you have been feeling tired for a long while, then compare yourself to how you felt when you were last well.
Please tick only one circle per line.:

Less than unual No more than usual More than usual Much more than usual
0 1 2 3 4 5 6 7 8 9 10
1.   Do you have problems with tiredness?
2.   Do you need to rest more?
3.   Do you feel sleepy or drowsy?
4.   Do you have problems starting things?
5.   Do you lack energy?
6.   Do you have less strength in your muscles?
7.   Do you feel weak?
8.   Do you have difficulties concentrating?
9.   Do you make slips of the tongue when speaking?
10. Do you find it more difficult to find the right word?
Better than unual No worse than usual Wores than usual Much worse than usual
11. How is your memory?

TEXT FOR YOUR RECORDS

This scale can be scored “bimodally” with columns representing 0, 0, 1 & 1 and a range from 0 to 11 with a total of 4 or more qualifying for “caseness”. Alternatively it can be scored in “Likert” style 0, 1, 2 & 3 with a range from 0 to 33. Mean “bimodal” score for CFS sufferers was 9.14 (SD 2.73) and for a community sample 3.27 (SD 3.21). Mean “Likert” score was 24.4 (SD 5.8) and 14.2 (SD 4.6). total (0-33) =

Cella, M. and T. Chalder (2010). "Measuring fatigue in clinical and community settings." J Psychosom Res 69(1): 17-22. This study involved 361 CFS sufferers and 1615 individuals from the community. Average age was in the 30’s. Fatigue levels were similar for males and females. A score of 29 discriminated between CFS sufferers and the community sample in 96% of cases and a score in the 30’s discriminated in 100% of cases. The CFS sufferers also scored a mean of 26.99 on the Work & Social Adjustment Scale (W&SAS) with a SD of 8.6 (i.e. about 70% scoring between 18.4 and 35.6).

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Last update: 11/14/2021