The Postwar Hospitalization Experience of Gulf War Veterans Participating in U.S. Health Registries

Mortality among U.S. military participants at eight aboveground nuclear weapons test series

BACKGROUND

Approximately 235,000 military personnel participated at one of 230 U.S. atmospheric nuclear weapons tests from 1945 through 1962. At the Nevada Test Site (NTS), the atomic veterans participated in military maneuvers, observed nuclear weapons tests, or provided technical support. At the Pacific Proving Ground (PPG), they served aboard ships or were stationed on islands during or after nuclear weapons tests.

MATERIAL AND METHODS

Participants at seven test series, previously studied with high-quality dosimetry and personnel records, and the first test at TRINITY formed the cohort of 114,270 male military participants traced for vital status from 1945 through 2010. Dose reconstructions were based on Nuclear Test Personnel Review records, Department of Defense. Standardized mortality ratios (SMR) and Cox and Poisson regression models were used in the analysis.

RESULTS

Most atomic veterans were enlisted men, served in the Navy at the PPG, and were born before 1930. Vital status was determined for 96.8% of the veterans; 60% had died. Enlisted men had significantly high all-causes mortality SMR (1.06); officers had significantly low all-causes mortality SMR (0.71). The pattern of risk over time showed a diminution of the 'healthy soldier effect': the all-causes mortality SMR after 50 years of follow-up was 1.00. The healthy soldier effect for all cancers also diminished over time. The all-cancer SMR was significantly high after 50 years (SMR 1.10) primarily from smoking-related cancers, attributed in part to the availability of cigarettes in military rations. The highest SMR was for mesothelioma (SMR 1.56) which was correlated with asbestos exposure in naval ships. Prostate cancer was significantly high (SMR 1.13). Ischemic heart disease was significantly low (SMR 0.84). Estimated mean doses varied by organ were low; e.g., the mean red bone marrow dose was 6 mGy (maximum 108 mGy). Internal cohort dose-response analyses provided no evidence for increasing trends with radiation dose for leukemia (excluding chronic lymphocytic leukemia (CLL)) [ERR (95% CI) per 100 mGy -0.37 (-1.08, 0.33); n = 710], CLL, myelodysplastic syndrome, multiple myeloma, ischemic heart disease, or cancers of the lung, prostate, breast, and brain.

CONCLUSION

No statistically significant radiation associations were observed among 114,270 nuclear weapons test participants followed for up to 65 years. The 95% confidence limits were narrow and excluded mortality risks per unit dose that are two to four times higher than those reported in other investigations. Significantly elevated SMRs were seen for mesothelioma and asbestosis, attributed to asbestos exposure aboard ships.

The occupational role of women in military service: validation of occupation and prevalence of exposures in the Millennium Cohort Study

To better understand the US military's global peacekeeping and combat operations, which may expose a growing population of American service women to challenging occupations and environments. Concordance between self-reported and electronic occupation codes for female participants in the Millennium Cohort was measured using kappa statistics. Multivariable logistic regression modeling was used to assess the odds of five self-reported potentially toxic environmental exposures or disturbing experiences among different occupational categories, while adjusting for demographic and military characteristics, including deployment. Self-reported occupations were moderately to highly reliable when compared with electronic occupation data. Active-duty and Reserve/Guard females differentially reported witnessing death or trauma and exposure to chemical or biological warfare, depleted uranium, or pesticides. Findings suggest that self-reported occupation can be used with a high degree of confidence. Occupational groups with higher odds of reporting military exposures of concern will be followed longitudinally through 2022 and prospectively compared using baseline and follow-up evaluations.

Asthma hospitalizations among US military personnel, 1994 to 2004

BACKGROUND

Acute asthma attacks strike unpredictably and may lead to hospitalization in otherwise healthy individuals. The burden of asthma hospitalization on the US health care system has greatly interested health care workers, many of whom see the incidence of asthma as increasing.

OBJECTIVES

To examine the annual incidence of hospitalization and the frequency of subsequent hospitalization for asthma among all active-duty US military personnel between 1994 and 2004 and to determine demographic and occupational risk factors of asthma hospitalization within this generally healthy US population.

METHODS

Annual demographic and occupational data were combined with electronic hospitalization records for patients with a discharge diagnosis of asthma. Using Cox proportional hazard modeling, the authors investigated demographic and occupational risk factors for asthma hospitalization.

RESULTS

Women, married persons, health care workers, enlisted personnel, US Army personnel, and older persons were found to have a significantly greater risk of asthma hospitalization. Yearly rates of hospitalization declined from 22.3 per 100,000 persons to 12.6 per 100,000 persons between 1994 and 2004.

CONCLUSIONS

Although these data have some limitations, they suggest that the burden of asthma hospitalizations in the large, healthy population of US military personnel has declined during the last decade. The decrease in hospitalization potentially reflects improved outpatient management strategies.

A comparison of the postdeployment hospitalization experience of U.S. military personnel following service in the 1991 Gulf War, Southwest Asia after the Gulf War, and Bosnia

Much attention has been given to the impact of deployment on the health of veterans from the 1991 Gulf War. Whereas increases in self-reported symptoms have been common, no specific exposures have been implicated. Some have suggested that stress from deployment is the chief cause for multisymptom conditions among Gulf War veterans, but comparisons with the health of other recent deployers have not been made. We sought to examine the impact of several large military deployments on hospitalization experience. Hospitalization records were examined for all active duty personnel deployed exclusively to the Gulf War, Southwest Asia after the Gulf War, or Bosnia. Cox's hazard modeling was used to assess time until first post-deployment hospitalization, separation from active duty, or December 31, 2000, whichever occurred first, while controlling for influential covariates and temporal changes. Personnel deployed to Southwest Asia after the 1991 Gulf War were at a slight increased risk for any-cause hospitalization and for 3 of the 14 major diagnostic categories when compared with veterans of the 1991 Gulf War. Personnel deployed to Bosnia were at a decreased risk for any-cause hospitalization and 12 of the 14 major diagnostic categories when compared with Gulf War veterans. These findings do not fully explain the complexity of postdeployment health experiences. Although the risk for hospitalization may be associated with regional deployment, it is unlikely that Gulf War veterans are at greater risk of hospitalization due to a specific exposure-related disease.

Millennium Cohort: enrollment begins a 21-year contribution to understanding the impact of military service

OBJECTIVE

In response to health concerns of military members about deployment and other service-related exposures, the Department of Defense (DoD) initiated the largest prospective study ever undertaken in the U.S. military.

STUDY DESIGN AND SETTING

The Millennium Cohort uses a phased enrollment strategy to eventually include more than 100,000 U.S. service members who will be followed up through the year 2022, even after leaving military service. Subjects will be linked to DoD and Veterans Affairs databases and surveyed every 3 years to obtain objective and self-reported data on exposures and health outcomes.

RESULTS

The first enrollment phase was completed in July 2003 and resulted in 77,047 consenting participants, well representative of both active-duty and Reserve/Guard forces. This report documents the baseline characteristics of these Cohort members, describes traditional, postal, and Web-based enrollment methods; and describes the unique challenges of enrolling, retaining, and following such a large Cohort.

CONCLUSION

The Millennium Cohort was successfully launched and is becoming especially relevant, given current deployment and exposure concerns. The Cohort is representative of the U.S. military and promises to provide new insight into the long-term effects of military occupations on health for years to come.

Neurological disorders in Gulf War veterans

We present a review of neurological function in Gulf War veterans (GWV). Twenty-two studies were reviewed, including large hospitalization and registry studies, large population-based epidemiological studies, investigations of a single military unit, small uncontrolled studies of ill veterans and small controlled studies of veterans. In nearly all studies, neurological function was normal in most GWVs, except for a small proportion who were diagnosed with compression neuropathies (carpal tunnel syndrome or ulnar neuropathy). In the great majority of controlled studies, there were no differences in the rates of neurological abnormalities in GWVs and controls. In a national US study, the incidence of amyotrophic lateral sclerosis (ALS) seems to be significantly increased in GWVs, compared to the rate in controls. However, it is possible that military service, in general, might be associated with an increased risk of ALS, rather than Gulf War service in particular. Taken together, the conclusion is that if a neurological examination in a GWV is within normal limits, then extensive neurological testing is unlikely to diagnose occult neurological disorders.

The mental health of U.S. military women in combat support occupations

BACKGROUND

The proportion of women in the U.S. military is increasing, and they are being selected into jobs that are more combat related. However, the mental health effects of working in combat support occupations among military women have not been previously evaluated.

METHODS

Active-duty enlisted Navy and Marine Corps women in combat support (n = 10,299) and noncombat support (n = 63,478) occupations were followed for 2 years between January 1, 1994, and August 31, 2001. Hospitalization diagnoses were examined and organized into eight categories of mental disorders; Cox proportional hazards modeling was used to describe these outcomes.

RESULTS

Women in combat support occupations were found to be significantly less likely to be hospitalized for a mental disorder than women in all other military occupations.

CONCLUSIONS

These results are reassuring but may be confounded by a healthy worker selection effect. Further studies are needed to assess how service in combat support occupations affects the long-term health of U.S. military women.

Self-reported reproductive outcomes among male and female 1991 Gulf War era US military veterans

BACKGROUND

Following the 1991 Gulf War, some veterans expressed concerns regarding their reproductive health. Our objective was to assess whether an association exists between deployment to the 1991 Gulf War and self-reported adverse pregnancy outcomes.

METHODS

Using a modified Dillman technique with telephone follow-up, we conducted a survey via a postal questionnaire from February 1996-August 1997 to compare selected reproductive outcomes among 10,000 US veterans deployed to the 1991 Gulf War with those of 10,000 nondeployed Gulf War era veterans.

RESULTS

A total of 8742 individuals responded to the survey, a response rate of 51 percent. Using multivariable analyses, results showed no differences in number of reported pregnancies between Gulf War veterans and nondeployed veterans. Among 2233 female and 2159 male participants, there were no differences in birth weight of infants born to Gulf War veterans compared with nondeployed Gulf War era veterans. In multivariable models, male and female Gulf War veterans did not significantly differ in risk for ectopic pregnancies, stillbirths, or miscarriages when compared with nondeployed veterans of the same era.

CONCLUSIONS

These results do not suggest an association between service in the 1991 Gulf War and adverse reproductive outcomes for both male and female veterans during the 4 years after the war.

Healthcare utilization and mortality among veterans of the Gulf War

The authors conducted an extensive search for published works concerning healthcare utilization and mortality among Gulf War veterans of the Coalition forces who served during the 1990-1991 Gulf War. Reports concerning the health experience of US, UK, Canadian, Saudi and Australian veterans were reviewed. This report summarizes 15 years of observations and research in four categories: Gulf War veteran healthcare registry studies, hospitalization studies, outpatient studies and mortality studies. A total of 149728 (19.8%) of 756373 US, UK, Canadian and Australian Gulf War veterans received health registry evaluations revealing a vast number of symptoms and clinical conditions but no suggestion that a new unique illness was associated with service during the Gulf War. Additionally, no Gulf War exposure was uniquely implicated as a cause for post-war morbidity. Numerous large, controlled studies of US Gulf War veterans' hospitalizations, often involving more than a million veterans, have been conducted. They revealed an increased post-war risk for mental health diagnoses, multi-symptom conditions and musculoskeletal disorders. Again, these data failed to demonstrate that Gulf War veterans suffered from a unique Gulf War-related illness. The sparsely available ambulatory care reports documented that respiratory and gastrointestinal complaints were quite common during deployment. Using perhaps the most reliable data, controlled mortality studies have revealed that Gulf War veterans were at increased risk of injuries, especially those due to vehicular accidents. In general, healthcare utilization data are now exhausted. These findings have now been incorporated into preventive measures in support of current military forces. With a few diagnostic exceptions such as amyotrophic lateral sclerosis, mental disorders and cancer, it now seems time to cease examining Gulf War veteran morbidity and to direct future research efforts to preventing illness among current and future military personnel.

Saudi Arabia-United States collaboration in health research: a formula for success

The aim of this article is to share our experiences from an international collaborative effort to study health outcomes among Saudi Arabian National Guard (SANG) soldiers following the 1991 Gulf War. By paying particular attention to distinct social and religious customs, geopolitical differences, and unique aspects of the health care system, we achieved a successful international collaboration in health research.