Table A1.

Kansas GWI and CDC GWI Components ¹.

Kansas GWI Components
Symptom Domain
Fatigue/sleep problems (4 symptoms)	“Fatigue”, “Feeling unwell after exercise”, “Difficulties getting to or staying asleep” 3, “Not feeling rested after sleep”
Pain (3 symptoms)	“Pain in joints”, “Pain in muscles”, “Body pain where you hurt all over”
Neurologic/Cognitive/Mood (14 symptoms)	“Difficulty remembering recent information”, “Feeling irritable or having angry outbursts”, “Numbness or tingling in extremities”, “Headaches”, “Eyes very sensitive to light”, “Trouble finding words when speaking”, “Feeling down or depressed”, “Difficulty concentrating”, “Night sweats”, “Feeling dizzy, lightheaded or faint”, “Low tolerance for heat or cold”, “Symptoms in response to smells or chemicals”, “Blurred or double vision”, “Tremors or shaking”
Gastrointestinal (3 symptoms)	“Diarrhea”, “Nausea or upset stomach”, “Abdominal pain or cramping”
Respiratory (3 symptoms)	“Difficulty breathing”, “Frequent coughing without a cold”, “Wheezing in chest”
Skin (2 symptoms)	“Skin rash” and “Other skin problems”
Exclusionary Criteria	Cancer (brain, breast, colon, lung, prostate, melanoma, other), Diabetes Heart disease (heart attack, coronary artery disease, congestive heart failure) Stroke (stroke and transient ischemic attack) Infection (HIV, tuberculosis, hepatitis C) Liver disease Lupus Mental health (schizophrenia and bipolar disorder) Neurological (multiple sclerosis and traumatic brain injury [TBI])
CDC GWI Components
Symptom Domain
Fatigue (1 symptom)	“Fatigue”
Musculoskeletal (3 symptoms)	“Pain in joints”, “Pain in muscles”, “Stiffness in joints”
Mood/Cognition (6 symptoms) 2	“Difficulty remembering recent information”, “Trouble finding words when speaking”, “Feeling moody”, “Feeling down or depressed”, “Difficulty concentrating”, “Difficulty getting to or staying asleep” 3, and “Feeling anxious”

GWI = Gulf War Illness; CDC = Centers for Disease Control and Prevention; VA = Department of Veterans Affairs; CSP = Cooperative Studies Program; ¹ Differences between CSP585 and CSP2006 were in how the question was asked. CSP2006’s question stem: “Indicate No or Yes for each. Have you had a persistent or recurring problem with…?” vs. CSP585 question stem: Indicate No or Yes for each. Over the PAST 6 MONTHS, have you had a persistent or recurring problem with…? Another difference was that CSP2006 asked if participants had melanoma whereas CSP585 questionnaire did not. ² The six symptoms were based on seven items in VA CSP 585. Specifically, to reflect the original CDC wording, the highest level of symptom presence/severity from questions regarding “Difficulty remembering recent information” and “Difficulty concentrating” were combined to create one symptom category. ³ This symptom is used in both the Kansas and CDC GWI case criteria; however, it is included in the fatigue domain in the Kansas definition and in mood–cognition domain in the CDC definition.