deployed veterans. Objective measures failed to show an increased prevalence of hospitalizations among active-duty Gulf War veterans, cancer (results for testicular cancer were inconsistent), peripheral neuropathy, cardiovascular disease, diabetes, or pulmonary function. The committee noted the few studies that attempted to link specific exposures, such as oil-well fire smoke and possible nerve agents released at Khamisiyah, to health outcomes. Only self-reports of exposure to oil-well fires were linked to an increase in self-reported respiratory symptoms that were suggestive of asthma and bronchitis.
As described in Chapter 4, the Update committee used a different approach for reviewing the literature. It considered studies that used only self-reports by Gulf War veterans to be secondary studies for most health outcomes; the major exception to this rule was multisymptom illness. However, some health outcomes, such as fibromyalgia or irritable bowel syndrome, lack objective diagnostic tests and are diagnosed based on symptom reporting that meet accepted criteria (for example, the Centers for Disease Control and Prevention criteria for chronic fatigue syndrome and the Rome criteria for irritable bowel syndrome). When the symptom reporting was sufficiently descriptive to meet the diagnostic criteria for that outcome, those studies were considered to be primary if the other evaluation criteria for a primary study (described in Chapter 4) were met. Studies that used objective measures to diagnose a health outcome were also considered to be primary if they met the other evaluation criteria.
The conclusions reached by the committee regarding the strength of the association between deployment to the Gulf War and each health outcome are summarized below. The committee notes that the majority of studies that it reviewed were conducted on both men and women, but for most studies, results for women were not presented separately as the number of women was relatively small. Results specific for women were presented in Chapter 4.
Evidence is sufficient to conclude that a causal relationship exists between being deployed to the Gulf War and a health outcome. The evidence fulfills the criteria for sufficient evidence of a causal association in which chance, bias, and confounding can be ruled out with reasonable confidence, and is supported by several of the other considerations used to assess causality: strength of association, dose-response relationship, consistency of association, temporal relationship, specificity of association, and biological plausibility.
Evidence suggests an association, in that a positive association has been observed between deployment to the Gulf War and a health outcome in humans; however, there is some doubt as to chance, bias, and confounding.
Other psychiatric disorders, including generalized anxiety disorder, depression, and substance abuse, particularly alcohol abuse. Furthermore these psychiatric disorders persist for at least 10 years after deployment.
Gastrointestinal symptoms consistent with functional gastrointestinal disorders such as irritable bowel syndrome and functional dyspepsia.
Chronic fatigue syndrome.