Links To The CDC CFS Symptom Inventory And To The Scoring Algorithm To The CDC CFS Symptom Inventory

In this post, I link to the 40 page PDF, CDC CFS Symptom Inventory, and to the Scoring Algorithm To The CDC CFS Symptom Inventory. Both accessed 12/8/2022.

Here is the first page of the three page PDF of the Scoring Algorithm To The CDC CFS Symptom Inventory.

Scoring Algorithm of CDC Symptom Inventory


The new version of the CDC Symptom Inventory (SI) collects information about the presence, duration, frequency, and intensity of 19 fatigue and illness-related symptoms that are listed by alphabetical letters from A to S. Nine sets of questions query the information regarding the following CFS-defining symptoms:

• Sore throat (Question A)
• Tender Lymph Nodes and Swollen Glands (Question B)
• Fatigue After Exertion (Question D)
• Muscle Aches and Pains (Question E)
• Joint Pain (Question F)
• Unrefreshing Sleep (Question I)
• Headaches (Question K)
• Memory Problems (Question L) or Concentration (Question M)

The pattern of questions is the same for each symptom. The symptom is introduced in the first question (capital letter), followed by 6 subquestions (decimal 1 through 6).
Using “sore throat” as an example, the first question is A, followed by A.1, A.2, A.3, A. 4, A.5, and A.6. The subquestions address the frequency, intensity and duration of the symptom. A skip pattern is used to avoid asking questions about symptoms that the participant has not had in the past month. In this situation only the introductory question and the last question (addressing symptom in the past) are answered. The response
choices for these subquestions about frequency, intensity,  and duration of a symptomare as follows:

• Frequency of each symptom – question X.1

o a = a little of the time
o b = some of the time
o c = a good bit of the time
o d = most of the time
o e = all of the time

• Intensity of symptoms – question X.2

o a= very mild
o b= mild
o c = moderate
o d = severe
o e = very severe

• Duration of symptoms – question X.3

o a = less than 6 month
o b = 6-12 months
o c = more than 12 months

where X represents the letter of each symptom; X=A, B, …, T.


October 30, 2010 Page 1

This entry was posted in Centers For Disease Control And Prevention, Myalgia Encephalomyelitis, Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Bookmark the permalink.