In response to requests from the DoD, the VA, and the Commonwealth of Pennsylvania, Fukuda and colleagues (1998) conducted a factor analysis study in 1995 to assess health status and prevalence and causes of an unexplained illness in Gulf War deployed and nondeployed members of a currently active Air National Guard unit (n = 667). Three demographically similar air force units were used as comparison groups (n = 538, 838, and 1680). Questionnaires regarding military characteristics, demographics, health status, and 35 specific symptoms previously identified to be of concern were distributed and completed by 3723 participants (1163 Gulf War deployed, 2560 nondeployed). Participation rates were as follows: 62% index unit; 35% unit A; 73% unit B; and 70% unit C. To assess symptom prevalence, investigators combined the four units and compared questionnaire responses of deployed and nondeployed. The authors further studied health outcomes in a subset of participants from the index unit of the Pennsylvania Air Force National Guard. Of the 490 (45%) deployed members of this unit, 173 (35%) volunteered to participate in the clinical evaluation and completed a mailed clinical questionnaire and the SF-36. This study is discussed in Chapter 4.
A nested case-control study of the same cohort (n = 1002) sought to identify self-reported exposures associated with cases of chronic multisymptom illness (Nisenbaum et al., 2000). Results indicate that meeting the case definition of severe and mild-to-moderate illness was associated with use of PB, use of insect repellent, and belief in a threat from biologic or chemical weapons. Having an injury requiring medical attention was also associated with having a severe case of chronic multisymptom illness. Nisenbaum et al. (2004) conducted a factor analysis of the symptoms reported by the UK Gulf War veterans combined with those reported by the Pennsylvania Air Force veterans. Further details from these studies are discussed in Chapter 4.
One of the first epidemiologic studies of US Gulf War veterans was a congressionally mandated study evaluating the psychologic and physical health of active-duty and reserve army, navy, air force, and marine personnel from bases in Pennsylvania and Hawaii (Stretch et al., 1995). Self-reported questionnaires were mailed to 16,167 potential study participants and inquired about the following: demographics; physical, psychological, and psychosocial symptoms; deployment type; and perceived sources of stress prior to, during, and after combat or deployment. A total of 4334 veterans returned the questionnaires for a response rate of 31%. Of those, 715 active duty and 766 reserves were deployed to the Gulf War; 1576 active duty and 948 reserves were not deployed. Findings are discussed in Chapter 4.
Two derivative studies of Stretch et al. (1995) were identified. In response to a questionnaire, deployed veterans commonly reported significant levels of stress during deployment, including operating in desert climates, long duty days, extended periods in