Is there a Persian Gulf War syndrome? Evidence from a large population-based survey of veterans and nondeployed controls

PURPOSE: Concerns have been raised about whether veterans of the Gulf War have a medical illness of uncertain etiology. We surveyed veterans to look for evidence of an illness that was unique to those deployed to the Persian Gulf and was not seen in comparable military controls. SUBJECTS AND METHODS: A population-based sample of veterans (n = 1,896 from 889 units) deployed to the Persian Gulf and other Gulf War-era controls (n = 1799 from 893 units) who did not serve in the Gulf were surveyed in 1995-1996. Seventy-six percent of eligible subjects, including 91% of located subjects, answered questions about commonly reported and potentially important symptoms. We used factor analysis, a statistical technique that can identify patterns of related responses, on a random subset of the deployed veterans to identify latent patterns of symptoms. The results from this derivation sample were compared with those obtained from a separate validation sample of deployed veterans, as well as the nondeployed controls, to determine whether the results were replicable and unique. RESULTS: One half (50%) of the deployed veterans and 14% of the nondeployed controls reported health problems that they attributed to military service during 1990-1991. Compared with the nondeployed controls, the deployed veterans had significantly greater prevalences of 123 of 137 (90%) symptoms; none was significantly lower. Factor analysis identified three replicable symptom factors (or patterns) in the deployed veterans (convergent correlations greater than or equal to 0.85). However, these patterns were also highly replicable in the nondeployed controls (convergent correlations of 0.95 to 0.98). The three factors also accounted for similar proportions of the common variance among the deployed veterans (35%) and nondeployed controls (30%). CONCLUSIONS: The increased prevalence of nearly every symptom assessed from all bodily organ systems among the Gulf War veterans is difficult to explain pathophysiologically as a single condition. Identification of the same patterns of symptoms among the deployed veterans and nondeployed controls suggests that the health complaints of Gulf War veterans are similar to those of the general military population and are not consistent with the existence of a unique Gulf War syndrome. Am J Med. 2000;108:695-704. (C)2000 by Excerpta Medica, Inc.