(95% CI 0.8-1.8) adjusted for sex, age, marital status, education, rank, and employment status. CFS was associated with reported exposures to combat-related injury (OR 4.1, 95% CI 2.2-7.7), explosions of Scuds (OR 2.6, 95% CI 1.5-4.6) or artillery (OR 2.4, 95% CI 1.4-4.1), hearing chemical alarms (OR 2.5, 95% CI 1.2-5.3), witnessing a person’s death (OR 2.2, 95% CI 1.3-3.8), seeing maimed soldiers (OR 2.0, 95% CI 1.2-3.6), and burning rubbish or feces (OR 2.0, 95% CI 1.0-3.4).
In a telephone survey of Iowa veterans of the Gulf War, a greater prevalence of chronic fatigue symptoms was reported by regular military (1.0%, n = 985) and National Guard/reserve (2.9%, n = 911) veterans than by nondeployed regular (0.2%, n = 968) and National Guard/reserve veterans (1.1%, n = 831) (Iowa Persian Gulf Study Group 1997). The statistically significant increased prevalence rate difference between deployed and nondeployed veterans was 1.4 (95% CI 0.9-2.0) after adjustment for age, sex, race, branch of military, and rank. The presence of a CFS-like condition was based on a combination of symptoms given in the CDC criteria (Freeman et al. 2005) and scores on the Chalder fatigue scale, a widely used scale to measure physical and mental fatigue in CFS patients (Putnam et al. 2006). The overall response rate was high (76%).
Canada deployed about 4500 troops to the gulf region in 1991 to provide naval operations and medical support. In 1997, a survey of the health status of the entire Canadian Gulf War forces was undertaken, comparing Gulf War-deployed troops with Canadian forces deployed elsewhere at the time (Goss Gilroy Inc. 1998). The assessment was based on a mailed survey that used the same questions as were used by the Iowa Persian Gulf Study Group (1998). Deployed veterans were more than 5 times as likely as nondeployed veterans to report symptoms of CFS (OR 5.27, 95% CI 3.95-7.03). Veterans who had served with land units had a slightly higher risk of CFS than those who served in air or sea units (OR 1.56, 95% CI 1.15-2.12). The response rate of the Gulf War veterans was 73%.
A cross-sectional mailed survey by Unwin et al. (1999) of three cohorts of UK veterans—3284 deployed to the gulf, 1815 deployed to Bosnia, and 2408 nondeployed—found that self-reported CFS (or myalgic encephalitis) was more strongly associated with deployment to the gulf than with deployment to Bosnia (OR 2.1, 95% CI 1.1-4.0) or no deployment (OR 2.7, 95% CI 1.6-4.6). ORs were adjusted for age, smoking, alcohol consumption, marital status, education, rank, employment, military or civilian status on followup, and a general health questionnaire. The prevalence of CFS (or myalgic encephalitis) was low in all the cohorts—3.3% in the gulf, 0.8% in the Bosnia, and 0.8% in the era cohort—although reports of symptoms of fatigue were relatively common: 50.7%, 26.3%, and 27.7%, respectively. Fatigue was associated with belief of exposure to chemical attack.
Zhang et al. (1999) reported that Gulf War veterans with CFS have several immune-function abnormalities in lymphocyte subpopulations not seen in healthy veterans or in civilians with CFS.
Only one secondary study examined the relationship between CFS and PTSD in Gulf War veterans. Kang et al. (2003) sent a self-administered 48-item questionnaire in 1995 to a large sample of active-duty, reserve, or National Guard veterans deployed during the Gulf War (n = 11,441) or not deployed (n = 9476). Current CFS-like illness was assessed according to responses to questions based on the CDC criteria for CFS (Fukuda et al. 1994); veterans had to have at least four of eight symptoms for 6 months or longer. The risk of current PTSD was