Eight derivative studies of the Iowa cohort were described in Volume 4 (Barrett et al., 2002; Black et al., 1999, 2000, 2004a,b; Doebbling et al., 2000; Lange et al., 2002). The Update committee identified three new studies of this cohort.
Subsequent cross-sectional studies of the Iowa cohort examined the presence of possible multiple chemical sensitivity (MCS) in these veterans, including the impact of MCS on quality of life and utilization of health services (Black et al., 1999) and the prevalence of and risk factors the development of MCS (Black et al., 2000).
Doebbling et al. (2000) used factor analysis to attempt to determine if the symptoms reported by Gulf War veterans after their deployment were different than those reported by nondeployed veterans and if the symptoms seen in the deployed veterans could possibly constitute a unique Gulf War syndrome.
Three studies assess the prevalence of psychiatric disorders in Gulf War deployed and nondeployed veterans. Barrett et al. (2002) examined the association between PTSD and self-reported physical health status. The prevalence of and risk factors for current anxiety disorder was studied by Black et al. (2004b) who used the PRIME-MD in a structured telephone interview to identify symptoms of anxiety. In a case-control study, however, Black et al. (2004a) used the SCID-IV to diagnose current or lifetime depression in 608 of the Iowa veterans, of whom 192 met the case definition for lifetime depressive disorder (132 deployed and 60 nondeployed). The prevalence of comorbid psychiatric diagnoses was determined. The findings of these studies are discussed in more detail in Chapter 4.
Lange et al. (2002) examined the impact of exposure of deployed Gulf War veterans to Kuwaiti oil-well fire and the prevalence of asthma and bronchitis 5 years after the war. Modeled exposures were developed using a geographic information system to integrate spatial and temporal records of smoke concentrations with troop movements ascertained from global positioning systems records. Results for modeled exposures were compared with self-reported exposures. More details are presented in Chapter 4.
The Update committee identified three new studies based on the Iowa cohort: Ang et al. (2006) and Forman-Hoffman et al. (2007) that both looked at the presence of chronic widespread pain in Iowa Gulf War veterans and Black et al. (2006) who assessed the prevalence of borderline personality disorder in the Iowa veterans.
Approximately 5 years after the initial survey described above, Ang and colleagues (2006) designed a follow-up evaluation to determine predictive factors for development of chronic widespread pain (CWP) in Gulf War veterans. A sample of 1040 veterans who previously met the criteria for cognitive dysfunction, CWP, and a control group was evaluated. Fifty-eight percent (n = 602) of the targeted population completed the assessment. Results indicated that deployment was not significantly associated with development of CWP; however, the association with combat exposure was significant. See Chapter 4 for more details.
Forman-Hoffman et al. (2007) also conducted a cross-sectional survey 5 years postconflict to determine the effect of deployment on the development of CWP in the Iowa cohort. The authors used the same 3695 participants as sampled in Black et al. (2006) below. Findings from this study are discussed further in Chapter 4.
Black and colleagues (2006) assessed the prevalence of borderline personality disorder (BPD) traits in a sample of the Iowa Persian Gulf War veterans using the Schedule for Adaptive and Nonadaptive Personality. The population was drawn from the initial 3695 surveyed individuals; a second assessment (in-person interviews and medical examinations) was