title: Symptom factor analysis, clinical findings, and functional status in a population-based case control study of Gulf War unexplained illness.
abstract: Few epidemiological studies have been conducted that have incorporated clinical evaluations of Gulf War veterans with unexplained health symptoms and healthy controls. We conducted a mail survey of 2022 Gulf War veterans residing in the northwest United States and clinical examinations on a subset of 443 responders who seemed to have unexplained health symptoms or were healthy. Few clinical differences were found between cases and controls. The most frequent unexplained symptoms were cognitive/psychological, but significant overlap existed with musculoskeletal and fatigue symptoms. Over half of the veterans with unexplained musculoskeletal pain met the criteria for fibromyalgia, and a significant portion of the veterans with unexplained fatigue met the criteria for chronic fatigue syndrome. Similarities were found in the clinical interpretation of unexplained illness in this population and statistical factor analysis performed by this study group and others.
authors.affiliation: Portland Veterans Affairs Medical Center, Department of Neurology, Mailcode P-3-NEURO, 3710 SW US Veteran's Hospital Road, Portland, OR 97201, USA. Dennis.Bourdette@med.va.gov
authors.forename: D N
authors.initials: DN
authors.lastname: Bourdette
authors.forename: L A
authors.initials: LA
authors.lastname: McCauley
authors.forename: A
authors.initials: A
authors.lastname: Barkhuizen
authors.forename: W
authors.initials: W
authors.lastname: Johnston
authors.forename: M
authors.initials: M
authors.lastname: Wynn
authors.forename: S K
authors.initials: SK
authors.lastname: Joos
authors.forename: D
authors.initials: D
authors.lastname: Storzbach
authors.forename: T
authors.initials: T
authors.lastname: Shuell
authors.forename: D
authors.initials: D
authors.lastname: Sticker
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015673:Fatigue Syndrome, Chronic / Q000209:etiology; D005356:Fibromyalgia / Q000209:etiology; D006306:Health Surveys; D006801:Humans; D008297:Male; D008877:Middle East; D016273:Occupational Exposure / Q000009:adverse effects / Q000706:statistics & numerical data*; D018923:Persian Gulf Syndrome / Q000150:complications / Q000453:epidemiology* / Q000209:etiology; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D014728:Veterans / Q000706:statistics & numerical data*; D014857:Warfare