veterans. In a randomly selected subset of veterans, medical record reviews verified more than 90% of self-reported reasons for clinic visits or hospitalizations (Kang et al., 2000).
Kang et al. (2000) did not assess exposure–symptom relationships but rather noted the percentage of veterans who reported each of 23 environmental exposures and nine vaccine or prophylactic exposures (such as to PB). The five most common environmental exposures reported by more than 60% of survey participants were to the following: diesel, kerosene, or other petrochemical fumes; local food other than that provided by the armed forces; chemical protective gear; smoke from oil-well fires; and burning trash or feces.
In Volume 4, seven derivative studies were identified: Davis et al. (2004), Eisen et al. (2005), Kang et al. (2001, 2002, 2003, 2005), and Karlinsky et al. (2004).
Davis et al. (2004) studied the presence of distal symmetric polyneuropathy (DSP) determined by medical history, physical examination by a neurologist, blood tests, and standardized electrophysiologic assessment of motor and sensory nerves in the cohort of 1061 deployed veterans and 1128 nondeployed veterans from the National Health Survey of Gulf War Veterans and Their Families. Spouses of deployed (n = 484) and nondeployed (n = 533) veterans were studied to evaluate whether an infectious agent or environmental contaminant brought back from the gulf could be responsible for any adverse health outcomes. Evaluations of 244 Khamisiyah-exposed (data provided by the DoD) versus 817 nonexposed deployed veterans for the presence of DSP were conducted. See Chapter 4 for more details.
In the third phase of the National Health Survey of Gulf War Veterans and Their Families, conducted 10 years after the Gulf War, Eisen and colleagues (2005) performed a cross-sectional study on numerous health outcomes of veterans 10 years after the Gulf War. The study population consisted of a stratified random sample of the 11,441 deployed and 9476 nondeployed veterans who participated in the above described phase I or II. This phase included a comprehensive medical examination and laboratory testing. Of the 1996 eligible deployed veterans, 1061 (53.1%) were examined; 680 (34.1%) declined and 255 (12.8%) were not located. Of the 2883 eligible nondeployed veterans, 1128 (39.1%) were examined; 1316 (45.7%) declined and 439 (15.2%) were not located. Despite three waves of recruitment into the study, the participation rate was low—60.9% of Gulf War deployed veterans and 46.2% of the nondeployed.
Study participants were assigned a medical center closest to their residence where physicians and nurses performed medical, neurologic, psychiatric, and gynecologic histories and examinations; laboratory, nerve conduction, pulmonary function, and neuropsychological tests were also performed. Twelve primary health outcome measures and physical functioning on SF-36 were examined.1 Outcome measures were chosen by the authors to cover the most common symptoms reported by veterans, such as musculoskeletal pain, fatigue, rashes, and neuropathy (Kang et al., 2000). Gulf War veterans reported worse physical health on the SF-36 (49.3 vs 50.8) but the magnitude of the difference, although statistically significant, was not clinically meaningful. Four of 12 conditions were more prevalent among Gulf War veterans: fibromyalgia (2.0% vs 1.2%), CFS (1.6% vs 0.1%), dermatologic conditions (34.6% vs 26.8 %), and dyspepsia (9.1% vs 6.0%). Further details are discussed in Chapter 4.