the committee’s charge is that the study’s findings are applicable not only to veterans of the 1991 Gulf War but to veterans of OEF and OIF.
To evaluate associations between deployment-related stress and adverse effects, the committee considered all studies that identified health effects found in military personnel deployed to a war zone. Deployment to a war zone would be used as a surrogate for deployment-related stress. The potential health effects considered included not only physiologic effects but psychologic effects, such as depression and PTSD, and psychosocial effects, such as marital conflict and incarceration. The committee also considered studies of deployed veterans with combat-related PTSD and associated health effects because PTSD can result only after exposure to a traumatic stressor and a war zone is rife with potentially traumatic events. In conducting its deliberations, the committee considered studies of veterans of World War II, the Korean War, the Vietnam War, the 1991 Gulf War, and OEF and OIF.
The committee sought to characterize and weigh the strengths and limitations of the available evidence regarding the association between deployment to a war zone and specific adverse health effects. The English-language scientific literature was searched to identify health effects in military veterans from World War II to the conflicts in Afghanistan and Iraq. Although most of the literature focused on U.S. military veterans, veterans from other countries were included. Over 3000 potentially relevant references were retrieved and assessed.
The committee used only peer-reviewed published literature as the basis of its conclusions. Committee members read each study critically and considered its relevance and quality. The committee did not collect original data, nor did it perform any secondary data analysis.
The committee also did not address policy issues—such as decisions regarding compensation, potential costs of compensation, or any broader policy implications of its findings—nor did it examine treatment approaches for any health effects.
When the committee had obtained the studies that met its inclusion criteria, it was necessary to establish which papers would constitute the foundation of its conclusions. In its review of the literature, the committee divided the available studies into two categories: primary and secondary.
The committee used primary studies as the basis of its evaluation and conclusions. A primary study demonstrates rigorous methods; for example, it includes details of its methods, has an appropriate control or reference group, has a sample size of at least 100, has the statistical power to detect effects, and includes reasonable adjustments for confounders. Ideally, it has information regarding a specific health effect and exposure. To consider a study as primary, the committee insisted that the health effect be diagnosed or confirmed by a clinical evaluation, specific laboratory test, hospital records, or other medical record or, for a psychiatric outcome, by standardized interviews. Primary studies included comparisons of veterans deployed to a war zone with their nondeployed counterparts and studies that evaluated health effects in veterans with deployment-related or combat-related PTSD.