the New Orleans cohort—and compared them with 48 veterans deployed to Germany during the Gulf War. They did not observe any significant differences between groups in chronic lung problems, chronic respiratory symptoms, or allergies. However, a number of other studies—including Gulf War veterans from several U.S. states (Iowa Persian Gulf Study Group 1997; McCauley et al. 2002b; Spiro et al. 2006; Steele 2000), Canada (Goss Gilroy Inc. 1998), Australia (O’Toole et al. 1996b), and the United Kingdom (Hotopf et al. 2006; Simmons et al. 2004; Unwin et al. 1999)—asked veterans about respiratory symptoms and found that deployed Gulf War veterans had a higher prevalence of self-reports of a variety of respiratory symptoms (colds, asthma, emphysema, chronic bronchitis, persistent cough, and lung disease) than nondeployed controls. Because of their reliance on self-reports or questionnaires, all those studies are vulnerable to recall or reporting bias and a lack specificity regarding the outcome.
Gray et al. (2002) found that Gulf War-deployed Seabees self-reported more asthma with onset after August 1991 (2.4%) than did Seabees deployed to areas other than the gulf (1.7%) or nondeployed Seabees (1.5%); that indicated that deployed Seabees were at increased risk for asthma compared with nondeployed Seabees (OR 1.82, 95% CI 1.23-2.69). However, although adjustments were made for age, sex, active-duty or reserve status, race or ethnicity, current smoking, and current alcohol drinking, exposures to a number of toxicants were possible confounders.
Gray et al. (1996) used hospitalization records from DoD medical facilities to compare the prevalence of ICD-9 respiratory diseases in 547,076 veterans deployed to the Gulf War compared with 618,335 nondeployed veterans. The OR for respiratory diseases decreased from slightly greater than 1 in 1991 to slightly less than 1 in 1993 (exact values not given).
Self-reported health status was assessed in a cross-sectional survey that used a mailed questionnaire sent to 1259 female U.S. veterans who received care at the VA Puget Sound Health Care System in 1996-1998 (Dobie et al. 2004). The women were screened for PTSD with the PTSD Checklist-Civilian Version. Compared with female veterans who did not have PTSD (n = 940), those with PTSD (n = 266) had a greater prevalence of emphysema (13.8% vs 10.7%, OR 1.88, 95% CI 1.21-2.92) and asthma (24.4% vs 17.3%, OR 1.64, 95% CI 1.17-2.31%) adjusted for age. It is unclear whether the excess of respiratory symptoms could be explained by higher rates of smoking in the veterans with PTSD (39.5% vs 22.9).
Boscarino (1997), using data from the VES, found a modest but significantly higher prevalence of respiratory diseases in Vietnam veterans who had lifetime combat-related PTSD (n = 1067) than in those without PTSD (n = 332) (OR 1.54, 95% CI 1.02-2.35, p = 0.042) adjusted for a variety of demographic, social, and Army characteristics.
A study of Gulf War veterans found no statistical difference in self-reporting of pulmonary symptoms (difficulty in breathing, shortness of breath, common cold or influenza, and rapid breathing) between deployed veterans with PTSD or MDD or both (n = 20) and deployed veterans with neither psychiatric condition (n = 178) or veterans who were deployed to Germany during the Gulf War (n = 48) (Wolfe et al. 1999).
The committee placed the greatest weight on studies that included a medical evaluation, identified specific respiratory diagnoses, and adjusted for potential confounding variables.