Chronic Multisymptom Illness Affecting Air Force Veterans of the Gulf War
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Chronic Multisymptom Illness Affecting Air Force Veterans of the Gulf War Keiji Fukuda, MD, MPH; Rosane Nisenbaum, PhD; Geraldine Stewart, MA; William W. Thompson, PhD; Laura Robin, DO, MPH; Rita M. Washko, MD; Donald L. Noah, DVM, MPH; Drue H. Barrett, PhD, MS; Bonnie Randall, MCP; Barbara L. Herwaldt, MD, MPH; Alison C. Mawle, PhD; William C. Reeves, MD, MSPH Context.—Gulf War (GW) veterans report nonspecific symptoms significantly was much lower than expected.9 No spe- more often than their nondeployed peers. However, no specific disorder has been cific illness is evident among the 18 598 identified, and the etiologic basis and clinical significance of their symptoms remain GW veterans, according to the Depart- unclear. ment of Defense Comprehensive Clini- 6 Objectives.—To organize symptoms reported by US Air Force GW veterans into cal Evaluation Program. Other investi- a case definition, to characterize clinical features, and to evaluate risk factors. gators have found no unusual increases in birth defects,10 unexplained illness,11 Design.—Cross-sectional population survey of individual characteristics and excess hospitalizations,12 or excess mor- symptoms and clinical evaluation (including a structured interview, the Medical tality13 among GW veterans. However, Outcomes Study Short Form 36, psychiatric screening, physical examination, clini- one study reported excess mortality due cal laboratory tests, and serologic assays for antibodies against viruses, rickettsia, to unintentional injuries rather than parasites, and bacteria) conducted in 1995. from disease.14 Evidence of an Iraqi Participants and Setting.—The cross-sectional questionnaire survey included chemical and biological weapons pro- 3723 currently active volunteers, irrespective of health status or GW participation, gram has been documented,15 and al- from 4 air force populations.The cross-sectional clinical evaluation included 158 though use of such weapons during the GW veterans from one unit, irrespective of health status. GW has not been confirmed,16 troops Main Outcome Measures.—Symptom-based case definition; case prevalence may have been exposed to chemical or rate for GW veterans and nondeployed personnel; clinical and laboratory findings biological warfare agents during the de- struction of storage bunkers. The long- among veterans who met the case definition. term effects of such chemical exposures Results.—We defined a case as having 1 or more chronic symptoms from at are uncertain, although some investiga- least 2 of 3 categories (fatigue, mood-cognition, and musculoskeletal). The preva- tors have suggested that wartime expo- lence of mild-to-moderate and severe cases was 39% and 6%, respectively, among sures may have contributed to chronic 1155 GW veterans compared with 14% and 0.7% among 2520 nondeployed per- neurotoxic syndromes.17,18 sonnel. Illness was not associated with time or place of deployment or with duties during the war. Fifty-nine clinically evaluated GW veterans (37%) were noncases, For editorial comment see p 1010. 86 (54%) mild-to-moderate cases, and 13 (8%) severe cases. Although no physi- cal examination, laboratory, or serologic findings identified cases, veterans who met the case definition had significantly diminished functioning and well-being. In December 1994, the US Secretary Conclusions.—Among currently active members of 4 Air Force populations, a of Defense and the Secretary of Veter- ans Affairs, and the Commonwealth of chronic multisymptom condition was significantly associated with deployment to the Pennsylvania asked the Centers for Dis- GW. The condition was not associated with specific GW exposures and also ease Control and Prevention (CDC), At- affected nondeployed personnel. lanta, Ga, to investigate a “mystery ill- JAMA. 1998;280:981-988 ness” reported among GW veterans from an Air National Guard (ANG) unit SOON AFTER cessation of Gulf War to concerns about a “Gulf War syn- in Lebanon, Pa.19 In the first phase of the (GW) hostilities, anecdotal reports of ill- drome.”1-3 Subsequent studies have investigation,weinterviewedandexam- ness and speculation over environmen- shown that GW veterans report numer- inedillGWveteransandfoundthattheir tal, biological, and chemical hazards led ous chronic nonspecific symptoms, such major health problems consisted of per- asfatigue,neurocognitiveproblems,and sistent fatigue and other chronic symp- From the Divisions of Viral and Rickettsial Diseases musculoskeletal pain, significantly more toms that began during deployment or (Drs Fukuda, Noah, Mawle, and Reeves) and Parasitic oftenthantheirnondeployedpeers.4,5 No soon after returning from the GW, but Diseases (Dr Herwaldt), National Center for Infectious widespread disorder has been linked to we did not find associated physical signs Diseases, the Division of Environmental Hazards and 4 Health Effects, National Center for Environmental that conflict, and the etiologic basis and or clinical laboratory abnormalities. Pa- Health (Dr Barrett), and the Epidemic Intelligence Ser- clinical significance of veterans’ symp- tients’ illnesses resembled those re- vice, Epidemiology Program Office (Drs Robin and tomatology remain unclear.6 ported previously, and the classification Washko), Centers for Disease Control and Prevention, 2 Atlanta, Ga; Klemm Analysis Group, Atlanta, Ga (Dr The evidence for unique health prob- and etiology remain unclear. Nisenbaum); and Abt Associates Inc, Cambridge, lems among GW veterans is mixed. Al- This article reports the second phase Mass (Mss Stewart and Randall and Dr Thompson). though acute gastroenteritis was fre- of our survey of the index ANG unit and Reprints: William C. Reeves, MD, MSPH, Centers for 7,8 Disease Control and Prevention, Mail Stop A-15, 1600 quently reported among troops, the 3 comparison air force populations. Our Clifton Rd, Atlanta, GA 30333 (e-mail: [email protected]). overall occurrence of infectious diseases primary objectives were to determine JAMA, September 16, 1998—Vol 280, No. 11 Chronic Illness Among Gulf War Veterans—Fukuda et al 981 ©1998 American Medical Association. All rights reserved. Downloaded From: by a Harvard University User on 03/12/2018 Table 1.—Factor Analysis Loadings (3 100) consecutive unit training weekends factors. After rotation, the factor pattern Exploratory Sample and Confirmatory Sample* (held monthly) to maximize participa- was examined to determine whether an Loading Values tion rates. Unit C was surveyed during oblique rotation yielded high loadings in a 10-day period. only one factor. Symptoms with factor Factor Factor On each base, one of us (K.F., L.R., loadings of greater than 0.40 were kept Symptoms PC 1 1PC22PC3R.W., or D.N.) met with small groups, fortheconfirmatoryfactoranalysis.22 The Depression 76 71 −3 −17 −1 explained the study, and distributed exploratory analysis yielded 10 compo- Anxiety 73 73 −5 −20 1 questionnaires to subject volunteers nents with an eigenvalue greater than 1. Moodiness 71 62 2 0 −10 whose identities remained anonymous. Memory 59 61 6 6 0 The first (feeling depressed, feeling anx- problems The questionnaire took 15 to 45 minutes ious, feeling moody, difficulty remember- Fatigue 50 50 19 19 3 to complete and queried health status, ing or concentrating, trouble finding Difficulty with 48 61 −15 −9 4 demographic and military characteris- words,difficultysleeping,andfatigue)ac- words tics, and potential risk factors for illness. counted for 16.8% of the total common Difficulty 45 42 30 14 −2 We asked about the 35 symptoms that variance.Thesecond(jointstiffness,joint sleeping hadbeenidentifiedduringtheearlierex- pain, and muscle pain) accounted for Joint stiffness 2 −5 85 76 4 ploratory study4 including their sever- 11.9% of the variance. The third (wheez- Joint pain 3 −13 84 85 −1 ity (mild, moderate, or severe) and du- ing, shortness of breath, coughing, and Muscle pain 0 12 63 47 1 ration (,6 months or $6 months). chest pain) accounted for 10.4%. The re- Wheezing −14 19 0 8 75 maining components each contributed Shortness of 10 35 3 21 73 Case Definition breath less than 10% of the total variance. Cough −8 29 2 13 59 We used 2 conceptually different ap- Confirmatory Factor Analysis.— Chest pain 11 33 0 17 53 proaches to develop exploratory case Only symptoms from the first 3 princi- definitions from the symptom data. The pal analysis components were used in the *The exploratory sample represents the first 3 prin- 23 cipal components of 35 symptoms submitted to a pro- first exploratory case definition was de- confirmatory factor analysis. These max oblique rotation (n = 1631). The confirmation factor rived from clinical and epidemiological symptoms were submitted to an un- analysis represents symptoms from the first 3 principal analysis components that were submitted to an un- reasoning; the second used statistical weighted least squares factor analysis 24 weighted, least squares factor analysis with a Pro- methods. with a Procrustes oblique rotation. Con- crustes oblique rotation (n = 1624). Intercorrelations for Clinical Approach.—We reasoned firmatory factor analysis identified 2 fac- factors 1 and 2 were 42% and 69%, respectively, for exploratory and confirmatory samples. PC indicates that if an illness existed among GW vet- tors (mood-cognition-fatigue and mus- principal components. erans, case-defining symptoms would be culoskeletal) (Table 1). chronic,prominentamongGWveterans, Preliminary Working Case Defini- whether the prevalence of symptoms and more common among GW veterans tions.—The 10 symptoms from factor was increased