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Research Topics
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 Research Topics    |    Major Focus Areas
Research Topics
General Health & Physical Symptoms
Project Summary

Title: Portland Environmental Hazards Research Center: Environment, Veterans' Gulf War Syndrome. Core: Clinical and Epidemiology Research
Synopsis: This abstract describes the overall plan for a multiyear study designed to evaluate the relationships between exposures (including chemical, physical, and stress) and unexplained illnesses in Gulf War veterans.
Overall Project Objective: To illuminate the relationships between exposures (chemical, physical, stress), and unexplained illness in Gulf War veterans.
Status/Results to Date: 1) Open-ended interviews of PGW veterans were completed, transcribed and summarized. Information gleaned from the interviews was incorporated in the questionnaire content. 2) Feasibility study was completed on 422 randomly selected Oregon veterans in the population to be studied. 3) Survey sampling plan for 1996-1998 was completed. As of August 1, 1998, we had received 1,136 completed surveys (out of 2,020 mailed surveys - 56% response rate). 4) Clinical testing of subjects responding to mail survey was completed in March 1998. 443 subjects were evaluated in the case-control study. 5) Mailings were made to 259 subjects living in rural areas of Oregon. In April 1997, and June 1997, we completed four days of satellite clinical evaluation of 45 of the responders from this sample in cooperation with the Roseburg, OR Veterans Administration Medical Center. In September and December 1997, we completed four days of satellite clinical evaluations of 33 of the responders from the Washington sample in cooperation with the Great Lakes VAMC in Tacoma, Washington. 6) Analyses have been completed in the following areas: A) Comparison of self-reported symptoms and symptoms reported at time of clinical evaluation; B) Reliability of self-reported exposure information, C) The association between deployment period and frequency of unexplained illness, D) Association between self-reported symptoms/clinical findings and specific exposures that took place while in SW Asia. 7) Description of the proportion of cases seen in the PEHRC clinic that fulfills the CDC 1988 and 1994 Chronic Fatigue Syndrome definitions. Analysis of the characteristics of veterans with fatiguing symptoms. Description of the extent with which fatigue overlaps with fibromyalgia and multiple chemical sensitivity. Comparison of the neuropsychological and neurobehavioral test results of cases with fatigue and other types of case symptoms. Comparisons of objective clinical findings (i.e. physical examination, neurological findings, laboratory tests) between veterans presenting with different symptom types and healthy controls. 8) Manuscripts under review or in preparation based on study results on the following topics: A) Chronic Fatigue in a Population of Veterans Deployed to the Gulf War, B) Clinical Findings and Symptom Factor Analysis in a Population-based Sample of Gulf War Veterans, C) Risk Factors Associated with Gulf War Unexplained Illnesses. 9) Findings to Date: A) The utility of our working case-definition was assessed and changes made. The definition was modified to reduce the number of symptom categories from five to three (unexplained fatigue, musculoskeletal complaints, and cognitive/psychological complaints). B) The factor analysis of the symptoms of the veterans in our study was compared to those published by others, they are most comparable with those described by the CDC (Fukuda et al., 1998). C) The persistence of self-reported symptoms was assessed and reported in papers and presentations by McCauley and Spencer 1997-1999. D) The reliability and validity of self-reported exposure data were assessed and reported in papers and presentations by McCauley and Spencer 1997-1999. E) Pyridostigmine and insecticide exposures postulated by others to be associated with GW unexplained illness (Haley & Kurt 1997) were not found to be significantly associated with the risk of having unexplained GW illness in our study sample. Models of factors associated with unexplained illness are more robust when the multisymptom case definition proposed by the CDC (Fukuda et al., 1998) was used. F) The estimated minimum prevalence of Chronic Fatigue Syndrome was 22/1000 veterans. This prevalence is significantly higher than that reported by Buchwald et al., (1995) in an ambulatory sample of persons residing in the NW United States. Timeline: Completion of data analysis and reports is anticipated by January 1, 2000.
Agency:Department Of Veterans' Affairs
Location:VAMC Portland
P.I. Name:Linda A McCauley, Ph. D., Peter Spencer, Ph. D.
Research Type:Clinical
Research Focus:Brain & Nervous System
Focus Category:General Health & Physical Symptoms
Study Start Date:October 01,1994
Estimated Completion Date:March 31,2000
Specific Aims: 1) To define "caseness" of unexplained illness in Gulf War veterans, 2) To develop a questionnaire of exposures and effects based on the results of veteran interviews and other relevant data, 3) To conduct a case-control study focused on the spatial-temporal relationship between exposures and illness, 4) To provide subjects for research conducted in Projects I, II, and part of IV.
Methodology: This is an epidemiological study using a population-based case-control design. Pilot work was conducted in two phases before final determination of the research protocol. The first phase consisted of fourteen open-ended interviews with veterans with varying degrees of health and diverse military exposures. The interviews were completed in the Spring of 1995. The second phase of the pilot work was a feasibility study in which a sample of 422 subjects randomly chosen from a data tape of Oregon and Washington residents serving in the Persian Gulf, was mailed a survey describing the proposed plan for the regional epidemiology study. Information was sought on potential response rates and barriers to participation. Modifications of the planned research protocol were made based on responses in the feasibility study. The design of the regional study consisted of mailing a questionnaire, seeking information on exposures in the Gulf, and current health status to approximately 3,000 northwest PGW veterans in 1996-97. The database used for the sampling frame was obtained from the DoD Defense Manpower Data Center. The database contains the names/addresses of military personnel who were deployed to the Persian Gulf from August 1990 through July 1991, and who listed Oregon or Washington as their home state-of-record. The accuracy of the addresses in the DoD database was determined in the feasibility study. Arrangements were made with the Department of Veterans Affairs NIOSH and IRS to track individuals with invalid addresses in the DoD file. In addition, Telematch, Equifax, Transunion, and numerous internet search machines were used to assist in finding current addresses and telephone numbers. The questionnaire was mailed in stages based on geographic location of the potential subjects. The survey methodology was developed in consultation with Jim Bethel, Ph.D., Survey Statistician, Westat Inc. Females and veterans in specific deployment groups (pre-combat, combat, post-combat) were over-sampled. From those who responded to the mailed questionnaire cases and controls (total approximately 500) were recruited for the clinical case-control study. The mailing of the survey questionnaire began in mid-November 1995 and the case-control clinical evaluations began in January 1996. Data collection was concluded in April 1998. The working case definition determined at the conclusion of the May 1995 Research Retreat (with input from an External Advisory Committee) was as follows: Must have at least one of the following signs or symptoms to be defined as a "Case". Onset must be during or after deployment to the Persian Gulf. Symptoms must have persisted for one month or longer and have occurred during the three month period preceding the proposed physical examination. A) Muscle/joint pain, B) Cognitive changes including memory loss, confusion, inability to concentrate, mood swings, and/or somnolence, C) Diarrhea, D) Skin or mucous membrane lesions, E) Unexplained fatigue Healthy controls and cases were identified from responses to the mailed questionnaire. Cases and controls received a medical workup at the Portland VAMC. Cases and controls participating in the clinical workup at the Portland VAMC also served as the subjects in Project I and II. Multivariant analyses were conducted to compare subjects with unexplained illness and healthy subjects with respect to reported and known exposures to specific environmental factors.
Most Recent Publications:

McCauley LA, Joos SK, Barkhuizen A, Shuell T, Tyree WA, Bourdette D. Chronic fatigue in a population-based study of Gulf War veterans. Archives of Environmental Health, 57(4):340-8. Jul-Aug 2002. Abstract

Shapiro SE, Lasarev MR, McCauley LA. Factor analysis of Gulf War illness: what does it add to our understanding of possible health effects of deployment? American Journal of Epidemiology, 156(6):578-585. Sep 2002. Abstract

McCauley LA, Joos SK, Lasarev MR, Storzbach D, Bourdette D. Gulf War unexplained illnesses: persistence and unexplained nature of self-reported symptoms. Environ Res, 81(3):215-23. Oct 1999. Abstract

McCauley LA, Lasarev MR, Sticker D, Rischitelli DG, Spencer PS. Illness experience of Gulf War veterans possibly exposed to chemical warfare agents. American Journal Preventive Medicine, 23(3):200-206. Oct 2002. Abstract

Anger WK, Storzbach D, Binder LM, Campbell KA, Rohlman DS, McCauley LA, Kovera CA, Davis KL. Neurobehavioral deficits in Persian Gulf Veterans: evidence from a population-based study. Journal of the International Neuropsychological Society, 5(3):203-12, Mar 1999. Abstract

Storzbach D, Campbell KA, Binder LM, McCauley LA, Anger WK, Rohlman DS, Kovera CA. Psychological differences between veterans with and without Gulf War unexplained symptoms. Portland Environmental Hazards Research Center. Psychosomatic Medicine, 62(5):726-35. Sept - Oct 2000. Abstract

Spencer PS, McCauley LA, Lapidus JA, Lasarev MR, Joos SK, Storzbach D. Self-reported exposures and their association with unexplained illness in a population-based case-control study of Gulf War veterans. Journal of Occupational and Environmental Medicine, 43(12):1041-56. Dec 2001. Abstract

Anger WK, Storzbach D, Binder LM, Campbell KA, Rohlman DS, McCauley LA, Kovera CA, Davis KL. Strategies to assess validity of self-reported exposures during the Persian Gulf War. Portland Environmental Hazards Research Center. Environ Res, 81(3):195-205, Oct 1999. Abstract

Binder LM, Storzbach D, Anger WK, Campbell KA, Rohlman DS. Subjective cognitive complaints, affective distress, and objective cognitive performance in Persian Gulf War veterans. Arch Clin Neuropsychol, 14:531-536, (Members of the PEHRC), 1999. Article

Bourdette D, McCauley LA, Barkhuizen A, Johnston W, Wynn M, Joos SK, Storzbach D, Shuell T, Sticker D. Symptom factor analysis, clinical findings, and functional status in a population-based case control study of Gulf War unexplained illness. Journal of Occupational and Environmental Medicine, 43(12):1026-40, Dec 2001. Abstract

McCauley LA, Rischitelli DG, Lambert WE, Lasarev MR, Sticker D, Spencer PS. Symptoms of Gulf War veterans possibly exposed to organophosphate chemical warfare agents at Khamisiyah, Iraq. Int J Occup Environ Health, 7(2):79-89. Apr - Jun 2001. Abstract

Spencer P, McCauley LA, Joos SK, Lasarev MR, Schuell T, Bourdette D, Barkhuizen A, Johnston W, Storzbach D, Wynn M, Grewenow R. U.S. Gulf War Veterans: service periods in theater, differential exposures, and persistent unexplained illness. Portland Environmental Hazards Research Centre. Toxicology Letters, 28;102-103:515-21, Dec 1998. Abstract