the prevalence of a diagnosis of fibromyalgia in the Eisen et al. study is about 300 times the prevalence of hospitalization for fibromyalgia in the Smith et al. study). The Iowa study (Iowa Persian Gulf Study Group 1997) and the Canadian study (Goss Gilroy Inc. 1998) both found significantly more fibromyalgia symptoms among deployed veterans than among nondeployed. The findings of those two studies, although generally supportive of the findings of the Eisen et al. study, are of limited value because the lack of a physical examination prohibits the use of the full criteria for diagnosis. The Bourdette study (2001), which did not have a nondeployed-veteran comparison group, estimated a minimum prevalence of 2.47% in the deployed veterans and used the full ACR case definition of fibromyalgia. In conclusion, largely on the basis of the Eisen et al. (2005) study, which used the criteria of the American College of Rheumatology for diagnosis of fibromyalgia but which could have been subject to unrecognized selection bias, there is a higher prevalence of fibromyalgia among deployed Gulf War veterans than among nondeployed veterans.
Other symptoms that are self-reported more often by deployed veterans are gastrointestinal symptoms, particularly dyspepsia; dermatologic conditions, particularly atopic dermatitis and warts; and joint pains.
There were many reports of gastrointestinal symptoms in Gulf War-deployed veterans. Those symptoms seem to be linked to reports of exposures to contaminated water and burning of animal waste in the war theater. The committee notes that several studies (e.g., Eisen et al. 2005) reported a higher rate of self-reported dyspepsia in Gulf War-deployed veterans than in nondeployed veterans. In the context of nearly all symptoms being reported more frequently in Gulf War veterans, it is difficult to interpret these findings.
For dermatologic conditions, a few studies included an examination of the skin and thus were more reliable than self-reports (e.g., Eisen et al. 2005); those have reported that a few unrelated skin conditions occurred more frequently among Gulf War-deployed veterans; however, the findings are not consistent. There is some evidence of a higher prevalence of two distinct dermatologic conditions, atopic dermatitis and verruca vulgaris (warts), in Gulf War-deployed veterans.
Arthralgias (joint pains) were more frequently reported among Gulf War veterans. Likewise, self-reports of arthritis were more common among those deployed to the gulf. Again, in the context of global reporting increases, such data are difficult to interpret. Moreover, studies that included a physical examination did not find evidence of a statistically significant increase in arthritis (Eisen et al. 2005).
Finally, Gulf War veterans consistently have been found to suffer from a variety of psychologic conditions. Two well-designed studies using validated interview-based assessments reported that several psychiatric disorders, most notably PTSD and depression, are 2-3 times more likely in Gulf War-deployed than in nondeployed veterans (Black et al. 2004; Wolfe et al. 1999). Moreover, comorbidities were reported among a number of veterans, with co-occurrence of PTSD, depression, anxiety, or substance abuse. Most of the other studies administered well-validated symptom questionnaires and their findings were remarkably similar: an overall two to three-fold increase in the prevalence of psychiatric disorders. When traumatic war exposures were assessed with symptoms, studies characteristically showed higher rates, particularly of PTSD, in veterans who had more traumatic war experiences than in those with lower levels of traumatic exposure. In other words, studies found a dose-response relationship between the degree of traumatic war exposure and PTSD. The finding of such a dose-response relationship provides increased confidence in the association with deployment.