====== Chronic Fatigue Syndrome (CFS) diagnostic score ======

Researchers from the [[https://www.rug.nl/staff/r.tendeiro-monden/|University Medical Center Groningen]] developed the Chronic Fatigue Syndrome (CFS) diagnostic score for adult participants using the [[fatigue_CDC|Fatigue (CDC) variables]]  from [[2a_questionnaire_2|2A Questionnaire 2]] and [[3a_questionnaire_1|3A Questionnaire 1]]. ([[sections]]: [[Diseases & symptoms]] ([[Fatigue (CDC)]]) and [[secondary & linked variables]]).\\

The CFS diagnostic score can be requested in the Lifelines catalogue or by mail (data@lifelines.nl).\\
\\
===== Calculation of CFS diagnostic score =====
To identify participants with a positive Chronic Fatigue Syndrome (CFS) diagnostic score, the 1994 Centers for Disease Control and Prevention ([[fatigue_CDC|CDC]]) criteria are taken into consideration. More specifically, participants have to meet three specific criteria in order to receive the CFS diagnosic score. In other words, if all criteria are met the participant receives a positive diagnostic score and when at least one of the criteria is zero the participant receives a negative CFS diagnostic score. If all three criteria are missing, the CFS diagnostic score is also missing. Below the three criteria are highlighted including details on the included statements in the calculation.

=== 1. Experience chronic fatigue for 6 or more months ===
| **IF...** | **THEN...** |
|fatigue_duration_adu_q_1>=4|CDC_criteria1=1|
|fatigue_duration_adu_q_1<4|CDC_criteria1=0|

=== 2. Fatigue significantly interfers with daily activities and work ===
| **IF...** | **THEN...** |
|fatigue_severity_adu_q_1>=4|CDC_criteria2=1|
|fatigue_severity_adu_q_1<4|CDC_criteria2=0|
with >= 4 is 'quite a bit' or 'a lot'. 

=== 3. Concurrently four or more out of eight additional symptoms are present ===
The eight additional symptoms are as follows: sore throat, tender lymph nodes, muscle pain, joint pain, headaches, unrefreshing sleep, unusual fatigue after exertion, forgetfulness, and difficulty concentrating. Please note: forgefulness and difficulty concentrating is treated as one symptom. >= 3 is 'a few times a week' or 'every day'.
| **IF...** | **THEN...** |
|cdc_forgetful_adu_q_01>=3|CDC_memory_concentration_combi=1|
|cdc_concentration_adu_q_02>=3|CDC_memory_concentration_combi=1|
|cdc_forgetful_adu_q_01<3 AND cdc_concentration_adu_q_02<3|CDC_memory_concentration_combi=0|
|cdc_forgetful_adu_q_01<3 AND SYSMIS(cdc_concentration_adu_q_02)|CDC_memory_concentration_combi=0|
|SYSMIS(cdc_forgetful_adu_q_01) AND cdc_concentration_adu_q_02<3|CDC_memory_concentration_combi=0|
|cdc_sorethroat_adu_q_03>=3|CDC_sorethroat=1|
|cdc_sorethroat_adu_q_03<3|CDC_sorethroat=0|
|cdc_tendernodes_adu_q_04>=3|CDC_lymphnodes=1|
|cdc_tendernodes_adu_q_04<3|CDC_lymphnodes=0|
|cdc_musclepain_adu_q_05>=3|CDC_musclepain=1|
|cdc_musclepain_adu_q_05<3|CDC_musclepain=0|
|cdc_jointpain_adu_q_06>=3|CDC_jointpain=1|
|cdc_jointpain_adu_q_06<3|CDC_jointpain=0|
|cdc_headache_adu_q_07>=3|CDC_headache=1|
|cdc_headache_adu_q_07<3|CDC_headache=0|
|cdc_notrested_adu_q_08>=3|CDC_unrefreshingsleep=1|
|cdc_notrested_adu_q_08<3|CDC_unrefreshingsleep=0|
|cdc_complaints_adu_q_09>=3|CDC_postexertionmalaise=1|
|cdc_complaints_adu_q_09<3|CDC_postexertionmalaise=0|
|count eight additional symptoms>=4|CDC_criteria3=1|
|count eight additional symptoms<4|CDC_criteria3=0|
|all eight additional symptoms missing|CDC_criteria3=MISSING|
\\
===== Variables =====
|**Label English**|**Label Dutch**|**Code**|**Variable**|**Assessment**|**Age**|
|Participant fulfills CDC criteria for Chronic Fatigue Syndrome (CFS)|Deelnemer voldoet aan CDC criteria voor chronisch vermoeidheidssyndroom (CVS)| cfs_cdc_adu_c_1|CFS_CDC_final|[[2a_questionnaire_2|2A]] [[3a_questionnaire_1|3A]]|18+|
\\