smoking. Active-duty Gulf War Seabees were significantly more likely than nondeployed Seabees to report either cough (OR 1.8, 95% CI 1.2-2.8) or shortness of breath (OR 4.0, 95% CI 2.2-7.3). Markers of pulmonary function did not differ between the deployed and nondeployed veterans: FVC 4.96 L vs 4.99 L, respectively (p = 0.77), and FEV1 4.05 L vs 4.04 L, respectively (p = 0.81). This study is limited in that it surveyed only active-duty Seabees.
In a cross-sectional survey comparing 1456 Australian Gulf War veterans with 1588 nondeployed veterans, study subjects gave self-reports of their respiratory symptoms in the preceding 12 months and underwent spirometric pulmonary-function testing and a physical examination (Kelsall et al. 2004b). The data were gathered in 2000-2002. Deployed veterans reported significantly more respiratory symptoms (wheeze, nocturnal chest tightness, cough, and dyspnea) than did nondeployed veterans. They also reported more asthma (OR 1.4, 95% CI 1.1-1.9) and chronic bronchitis (OR 1.9, 95% CI 1.2-3.1) but were not at increased risk for airflow limitations, defined as FEV1/FCV% < 70% (OR 0.8, 95% CI 0.5-1.1) or emphysema (OR 1.0, 95% CI 0.8-1.4). Furthermore, there were no statistically significant differences between deployed and nondeployed veterans in any lung-function indexes (FEV1, FCV, or FEV1/FVC%). ORs were adjusted for age, height, smoking, weight, atopy, rank, service, education, and marital status. The study used self-reports of a physician’s diagnosis or treatment for a diagnosis to determine the prevalence of asthma and bronchitis. During the medical-examination phase of the study, a physician queried each veteran about responses to the questionnaire regarding asthma and bronchitis and classified the likelihood of the diagnosis on a scale from unlikely to probable. Possible exposures to dust and oil-well fires were considered as possible contributors to the respiratory effects seen in the deployed veterans. Based on the European Community Respiratory Health Survey definition of respiratory disease, the only significant risk factor for increased asthma in deployed veterans was having an asthma attack or being awakened by shortness of breath at any time in the preceding 12 months or current use of asthma medications. For bronchitis, the only significant definition was having a doctor’s first diagnosis of chronic bronchitis in 1991 or later. However, if other definitions of the diseases were used, the differences between the two groups were not significant. The study had a response rate of 80.5% for the deployed veterans and 56.8% for the nondeployed.
Gray et al. (2000) conducted a study of hospital-discharge records of three hospital systems for 1991-1994: those of DoD, VA, and California Office of Statewide Health Planning and Development. PMRs of hospital-discharge diagnoses of 652,979 Gulf War veterans and 652,922 era veterans not deployed to the gulf were compared. With adjustment for age, sex, and race, the PMRs for respiratory-disease were 1.02 (95% CI 0.99-1.04) for the DoD hospitals, 1.19 (95% CI 1.10-1.29) for the VA hospitals, and 1.06 (95% CI 0.82-1.29) for the California hospitals.
The committee identified numerous large, well-designed studies of Gulf War veterans that it considered secondary mainly because the absence of examinations for respiratory effects led to imprecision regarding evaluation of respiratory disease or lack of adequate adjustment for major confounding variables.
In addition to the study by Kang et al. (2000b) discussed above, other large, well-designed cohort studies from several countries show mixed findings regarding the presence of respiratory disease in veterans based on self-reporting via questionnaires. Proctor et al. (1998) looked at 252 U.S. Gulf War-deployed veterans—186 from the Fort Devens cohort and 66 from