to diesel, kerosene, or other petrochemical fumes; to local food other than that provided by the armed forces; to chemical protective gear; to smoke from oil-well fires; and to burning trash or feces.
Three studies have reported on physical examinations of a subsample of the cohort that assayed for general medical status (Eisen et al. 2005), distal symmetric polyneuropathy (Davis et al. 2004), and pulmonary function (Karlinsky et al. 2004). The examinations were conducted in 2001, about 10 years after the Gulf War.
Eisen and colleagues (2005) examined 12 primary health outcome-measures and physical functioning on SF-36. Outcome measures were chosen by the authors to cover the most common symptoms reported by veterans, such as musculoskeletal pain, fatigue, rashes, and neuropathy (as noted in Kang et al 2000).
The study evaluated 1,061 Gulf War and 1,128 non-Gulf War veterans who had been randomly selected from 11,441 Gulf War-deployed and 9,476 non-Gulf War-deployed veterans who previously had participated in a 1995 questionnaire survey (Kang et al. 2000). Researchers were blind to deployment status. Despite three waves of recruitment into the study, the participation rate in the 2005 study was low: only 60.9% of Gulf War veterans and 46.2% of non-Gulf War veterans participated. To determine nonparticipation bias, the study authors obtained previously collected findings from participants and nonparticipants from the DOD Manpower Data Center and gathered sociodemographic and self-reported health findings from the 1995 VA study (Kang et al. 2000).
Four of 12 conditions were more prevalent among GW veterans: fibromyalgia (2.0% vs 1.2%; odds ratio [OR] 2.32, 95% confidence interval [CI] 1.02-5.27), CFS (1.6% vs 0.1%; OR 40.6, 95% CI 10.2-161.15), dermatologic conditions (34.6% vs 26.8 %; OR 1.38, 95% CI 1.06-1.80), and dyspepsia (9.1% vs 6.0%; OR 1.87, 95% CI 1.16-2.99). Fibromyalgia was diagnosed according to the 1990 criteria developed by the American College of Rheumatology (Wolfe et al. 1990). CFS was diagnosed according to the case definition developed by the International Chronic Fatigue Syndrome Study Group (Fukuda et al. 1994). The rate of CFS in the nondeployed veterans was similar to that of the US population. For dermatologic diagnoses, the study created two categories, one of which had a higher OR (see discussion in Chapter 5). A dyspepsia diagnosis required a history or symptoms of frequent heartburn and recurrent abdominal pain, and the use of antacids or other medications.
Gulf War veterans reported worse physical health on the SF-36 (49.3 vs 50.8; p < 0.001), but the magnitude of the difference, although statistically significant, was not clinically significant. The analyses adjusted for age, sex, race, years of education, cigarette smoking history, duty type (active vs reserves or National Guard), service branch (Army or Marines vs Navy or Air Force), and rank (enlisted vs officer). The limitations of the study were its performance 10 years after the 1991 Gulf War, which precludes diagnoses that have already resolved, and low participation rates (60.9% Gulf War and 46.2% non-Gulf War), which introduce the possibility of participation bias.
In the study by Davis et al. (2004), the presence of distal symmetric polyneuropathy was evaluated with a history, physical examination, and standardized electrophysiologic assessment of motor and sensory nerves in 1,061 deployed veterans and 1,128 nondeployed veterans. Spouses of deployed and nondeployed veterans were also used as controls. A population of 244