RESEARCH ON THE HEALTH STATUS OF GULF WAR VETERANS
DEPARTMENT OF VETERANS AFFAIRS

JOURNAL ARTICLE SUMMARIES
by J. Michael Howe, MSLS

Article Titles:

"Lessons Learned From the Department of Veterans Affairs"

"Gulf War Veterans' Health Registries. Who is Most Likely to Seek Evaluation?"

"Illnesses Among United States Veterans of the Gulf War: A Population-Based Survey of 30,000 Veterans"

"Mortality Among U.S. Veterans of the Persian Gulf War"

"The Postwar Hospitalization Experience of U.S. Veterans of the Persian Gulf War" 

"LESSONS LEARNED FROM THE DEPARTMENT OF VETERANS AFFAIRS"

Reference: Military Medicine, 164:327-331

Date: 1999

Authors: Frances M. Murphy, M.D., M.P.H., Han Kang, Dr.P.H., Nancy A. Dalager, M.S., Kyung Y. Lee, Ph.D., Robert E. Allen, Ph.D., Susan H. Mather, M.D., M.P.H., Kenneth W. Kizer, M.D., M.P.H.

Background

Within months of their return, some Gulf War veterans reported various symptoms and illnesses that they perceived to be associated with their service in the Persian Gulf. In response to these reports, the Department of Veterans Affairs (VA) created a Registry Health Examination Program. This program allows any Gulf War veteran with health concerns to obtain a systematic medical examination with appropriate baseline laboratory tests at VA medical centers nationwide. At the time of this article, more than 65, 000 Gulf War veterans had completed the registry examination, and selected information had been entered into a computer database. The purpose of this article is to review the demographic, military, and medical characteristics of Gulf War veterans who chose to participate in the program.

Health Status

Symptoms

A wide variety of nonspecific symptoms are reported by Gulf War Registry participants. The most frequent complaints include fatigue, skin rash, headache, muscle and joint pain, cognitive complaints, shortness of breath, sleep disturbances, diarrhea and other gastrointestinal symptoms, and chest pain.

Diagnosis

The most frequently diagnosed medical conditions are diseases of musculoskeletal and connective tissue, followed by mental disorders, diseases of the respiratory system, skin and subcutaneous tissue diseases, and digestive diseases. To date, no new, unique illness or syndrome has been identified among Gulf War registry examinees.

Women Veterans

In contrast to previous wars, a larger portion of deployed troops were women, and they served in a wider variety of military occupations than women veterans of previous wars. Relative to men, those women who participated in the original VA registry examination more frequently report experiencing symptoms of fatigue and headache and less frequently report having muscle and joint pain. These differences are small and may reflect gender-related differences.

Trends over 2.5 Years of Observation

The registry database was evaluated for five successive time periods, each representing a 7-month interval, between August 1992 and July 1995. The frequency of major symptoms (fatigue, skin rash, headache, muscle and joint pain, memory loss) in the 44,190 veterans included in this analysis showed an increasing trend over time. At the same time, reports of self perceived good or very good health status declined compared with the reports of veterans who were examined soon after the Gulf War.

Discussion

The Registry Health Examination Program was developed by the VA primarily as a means for veterans who returned from the Gulf War with health concerns to access medical care. Because of the inherent limitations recognized in this surveillance information, great caution should be exercised in the use of registry data. One cannot predict whether the prevalence (rates) of symptoms and diseases observed among registry participants represent the true prevalence of health problems among all troops deployed to the Persian Gulf region during this conflict. In recognition of these limitations, the VA is conducting as a separate study, a national health survey of a population-based representative sample of 15,000 deployed troops and an equal number of non-deployed troops. That survey is designed to provide more accurate estimates of the prevalence of various symptoms and other health outcomes among all Gulf War veterans, and to compare them with those of Gulf War-era veterans who did not serve in Operations Desert Shield/Desert Storm.

In summary, veterans participating in VA’s Registry Health Examination Program report a wide variety of symptoms, and receive a broad cross-section of diagnoses involving multiple organ systems as made by examining physicians. There is no notable internal variation in symptoms or diagnoses by military branch, service component, or gender. The proportion of military members who served in the active Army, Reserve, or National Guard units and women were over-represented in the VA registry compared with their numbers in the overall deployed troops. The frequency of registry examinees reporting major symptoms (fatigue, skin rash, headache, muscle and joint pain, memory loss) increased over time, and self-perceived good or very good health status decreased. The proportion of individuals with physician-diagnosed illnesses has remained fairly constant at 72 to 76%, and no single broad category of diseases has substantially changed over time.

It is possible that in the future, the dominant health impact of war may be measured predominantly by the adverse health consequences of postwar syndromes. Although the syndromes associated with past armed conflicts are characterized by similar symptoms as seen in Gulf War veteran registry participants, no single recurring illness has been found to explain their occurrence. Whether postwar somatic symptoms and medical conditions result from the harmful effects of environmental exposures, psychological factors, or other, as yet undesignated causes needs to be further explored by well-designed research that may require periodic screening throughout a military member’s career.

"GULF WAR VETERANS’ HEALTH REGISTRIES. WHO IS MOST LIKELY TO SEEK EVALUATION?"

Reference: American Journal of Epidemiology, 148:343-349

Date: 1998

Authors: Gregory C. Gray, M.D., M.P.H., Anthony W. Hawksworth, Tyler C. Smith, Han K. Kang, Dr.P.H., James D. Knoke, Gary D. Gackstetter

Since returning from the Persian Gulf War, some veterans have reported a variety of symptoms and illness that they attribute to the conflict. In response to early morbidity (illnesses) reports, voluntary federal clinical evaluation programs were offered to veterans after the Gulf War. The purpose of this study was to determine the risk facts for participation in these registry programs.

Materials and Methods

The Department of Veterans Affairs (VA) and the Department of Defense (DoD) established voluntary health registries in 1992 and 1994, respectively, to evaluate, document, diagnose, and provide medical care to Gulf War veterans who chose to participate. All clinicians in both departments follow a structured evaluation protocol, administering a comprehensive history and physical examination. Clinical diagnoses, symptoms, and self-reported exposures are recorded for each registry participant. Gulf War veterans were identified from Gulf War service data. As this was a historical (looking at the past) study, demographic variables were univariately compared with registry participation using risk ratio calculations.

Results

Active duty and veteran registry participants who, after clinical evaluation, were considered healthy were medically coded in several ways by registry clinicians. A high percentage (30.6 percent) of registry participants were described as the "worried well," personnel who sought medical attention, with or without symptoms, for whom no clinical diagnoses could be found. The 19 other most frequent principal diagnoses were similar to the numerous general and nonspecific symptoms that Gulf War veterans have reported. Over 50 percent of principal diagnoses were classified into four large categories: diseases of the musculoskeletal system and connective tissues (19.0 percent), mental disorders (14.7 percent), diseases of the respiratory system (10.5 percent), and diseases of the skin and subcutaneous tissue (9.4 percent).

All demographic variables had statistically significant univariate associations with the outcome of registry participation. Personnel at highest odds (chance) of participating in a health registry had served in the Army, had served in the National Guard, were in the Gulf War theater during the fighting, were older, were enlisted personnel, had been construction workers, were female, and had been hospitalized during the 12-month period before the war.

Discussion

This controlled study of the postwar hospitalization experience of Gulf War veterans demonstrated that they had no additional risk of developing musculoskeletal diagnoses when compared with non-deployed military operations. Several of the other common principal diagnoses were also consistent with the findings of controlled postwar hospitalization study in that registered Gulf War veterans had common mental disorder diagnoses. As with other wars, diagnoses such as adjustment disorder, depression, and anxiety states are recognized sequelae (result) of the physical and psychological trauma of war.

Because of the accompanying potential biases of self-selection and the differences in symptom diagnosis, the authors chose to focus this report on risk factors for the participation in the registry. Risk factor analyses for registry participation validated a recent DoD registry report and summary reports of the VA registry. Army personnel, Reserve and National Guard personnel, personnel of older age groups, and women were more likely to register for the health evaluations in these summaries. However, the authors’ note that their analyses are important in that they quantify, in a multivariate way with much statistical power, the independent risk factors for registry participation.

The authors’ recent controlled study (using a comparison group) of risk factors for post-war hospitalization in DoD hospitals demonstrated some parallels to the earlier registry risk factor findings. In that study, Army personnel, females, personnel of older age groups, married personnel, and health care workers were the most likely groups of people to be hospitalized. Additionally, Gulf War veterans who served during the actual combat period might be more likely to seek supplemental health evaluation compared to other Gulf War veterans. The slightly increased risk for separated personnel to participate in the registry is consistent with the suggestion that former active duty personnel may be more likely to seek medical evaluation to document service-related health conditions for which they merit compensation. The association of prewar hospitalization with registry participation was recently reported in a smaller analysis of Army Gulf War veterans. Although slight in magnitude, this may reflect health care-seeking behavior among registry participants.

These analyses have several important strengths: (1) the large Gulf War veteran and registry populations generated sufficient statistical power to detect small risk factor differences, and (2) the registry diagnostic data came from hundreds of clinicians (doctors) from medical centers throughout the United States and in some foreign counties. Several limitations of this study should be considered: (1) the study is based upon self-selected registry participants and can not be taken to represent the health status of the Gulf War veterans’ population as a whole; (2) the two registries serve different populations of eligible Gulf War veterans, and their administration may differ with respect to the availability of registry examination sites; and (3) risk factors for participation may change over time as veterans continue to enroll in these registries.

"ILLNESSES AMONG UNITED STATES VETERANS OF THE GULF WAR: A POPULATION-BASED SURVEY OF 30,000 VETERANS"

Reference: Journal of Occupational and Environmental Medicine, 42:491-501

Date: 2000

Authors: Han K. Kang, Dr.P.H., Clare M. Mahan, Kyung Y. Lee, Carol A. Magee, Frances M. Murphy, M.D., M.P.H.

In 1992 the Department of Veterans Affairs (VA) created a Gulf War Health Registry for veterans of the Gulf War. In June 1994, the Department of Defense (DoD) instituted a similar program, the Comprehensive Clinical Evaluation Program. At the time of this study, about 70,000 veterans had completed the VA registry examination, and about 30,000 active duty personnel were evaluated in the Comprehensive Clinical Evaluation Program. Both VA and DoD registry participants reported a broad range of symptoms that span a variety of organ systems with the most common diagnostic categories being the same in both registries.

The veterans in the registries are a self-selected group who may not be representative of all U.S. service members deployed during the Gulf War. There also is no useful comparison (control) group for these registries. Furthermore, the symptoms most frequently recorded are also very common in the general U.S. population. Because of the limitations of the Gulf War Health Registry, one cannot be certain whether various symptoms and illnesses reported in the registry are under-represented or over-represented. VA responded to the call to determine whether there was an increased prevalence of illnesses among veterans due to service in the Gulf War by developing a population-based (to reflect all Gulf War veterans) epidemiologic study with appropriate controls. It also included family members, because many veterans have reported poor pregnancy outcomes and birth defects in children conceived after the war. VA designed this survey as a cross-sectional (measuring health at a single point in time) study in which health factors of a population-based sample of 15,000 service members deployed into the Gulf was compared with those of 15,000 service members not deployed in the Gulf.

The purpose of this study was to estimate and compare the prevalence (rates) of various symptoms and other health conditions among Gulf War veterans with those of non-Gulf War veterans. In addition, the relationships between selected health conditions and the type of military unit/service were evaluated.

Methods

The groups from which the sample of 15,000 Gulf War and 15,000 non-Gulf War era (active duty but not deployed to the Gulf) veterans was selected were identified by the DoD. A self-administered questionnaire was used to obtain information from study participants concerning their exposure to possible risk factors, potentially confounding variables, the presence of various symptoms, measures of functional impairment and limitation of activity, and medical history. The questionnaire included a self-report symptom inventory, made up of 48 items that were representative of the symptoms commonly seen among outpatients, to assess the prevalence of somatic (bodily) and psychological symptoms; items from the National Health Interview Survey; and potential environmental risk factors of concern.

Discussion

The population-based (representative of all Gulf War veterans) sample of Gulf War veterans participating in the survey reported significantly higher rates of symptoms and medical conditions compared to era veterans who were not deployed to the Gulf War. Furthermore, they reported a 2-times higher rate of functional impairment and an almost 50% higher rate of limitation of employment or work due to health problems compared to the non-deployed era veterans. Gulf War veterans also sought more medical care and reported a higher prevalence of numerous, highly varied symptoms and medical conditions compared to their military peers.

Gulf War veterans also report being subjected to a wide variety of both natural and man-made potential environmental hazards. However, but objective data are not available or not adequately documented to confirm self-reported exposure history. In fact, the accuracy of some of the exposure rates may be questionable in view of the data released by DoD.

A major limitation of the survey is that both exposure and health information is based on the self-reported recollections of veterans, which may be subject to reporting or recall bias. However, there is evidence that the survey participants have reported their medical conditions and symptoms with a very high level of agreement with actual medical record documentation. A major strength of the survey is the study design that includes a large number of 15,000 deployed and 15,000 non-deployed veterans, who were randomly sampled to represent the respective military population. This survey is one of the few large population-based studies of Gulf veterans conducted to date.

In summary, the results of the survey indicate that Gulf veterans report being not as healthy as their military peers who were not deployed in the Persian Gulf as measured by functional impairment, health care utilization, general health perceptions, symptoms, and self-reported medical conditions.

"MORTALITY AMONG U.S. VETERANS OF THE PERSIAN GULF WAR"

Reference: The New England Journal of Medicine, 335:1498-1504

Date: 1996

Authors: Han K. Kang, Dr.P.H., Tim A. Bullman, M.S.

Background

Since the 1990-1991 Gulf War, there has been consistent concern that U.S. veterans may have suffered negative health consequences including increased mortality (death) due to external causes (motor vehicle accidents and accidents of other types, suicide, and homicide). The authors conducted a retrospective (looking into the past) cohort study of mortality in which they compared the postwar mortality of Gulf War veterans with that of veterans from the era of the Gulf War who did not serve in that conflict. This study complements the Department of Defense study of non-battle related deaths among Gulf War service members who remained on active duty.

Methods

The study included all of the 695,516 military personnel who served in the Persian Gulf from August 1990 to April 1991. A control comparison group of 746,291 military personnel consisted of a stratified random sample of approximately half of all personnel on active duty in the National Guard and in the military reserves who served from September 1990 to April 1991, but did not go to the Persian Gulf. Whether each Gulf War veteran was still alive was evaluated from the date the veteran left the Persian Gulf area using VA data. Death certificates were obtained and causes of death were recorded. The data obtained were analyzed in three stages: (1) the relative frequency of death overall, as well as death due to specific causes, was compared between the Gulf War veterans and the controls on the basis of the number of person-years at risk; (2) the Cox proportional-hazards model was used to account for possible confounding and the effect of selected covariates on the risk of a veteran's dying from a specific cause, according to the time since that veteran's entry into the cohort; and (3) the cause-specific mortality of Gulf War veterans and other veterans was compared with the number of deaths expected in the overall U.S. population after adjustment for age, sex, race, and year of death.

Results

The demographic and military characteristics of the Gulf War veterans were similar to those of the comparison controls except for the year of birth, sex, and type of unit. After controlling (correcting) for potential confounders (age, sex, race, and military variables), the Gulf War veterans had significantly higher mortality from all causes compared to controls. These excess deaths were entirely attributable to external causes, including all types of accidents and motor vehicle accidents. There was no observed excess of suicides, homicides, or deaths from disease-related causes. The risk of death from infectious and parasitic diseases was significantly lower among Gulf War veterans compared to other (control) veterans.

Relative-risk estimates derived from the Cox proportional-hazards model showed that overall mortality and mortality from all external causes, including accidents of all types and motor vehicle accidents, continued to be significantly elevated among Gulf War veterans compared to controls. In males, the risk of disease-related mortality was lower among Gulf War veterans compared to controls. The effect of mobilization to locations other than the Persian Gulf did not appear to affect the overall mortality or the risk of death from external causes, even after adjustment for the type of unit, age, sex, race, and branch of service. Compared with the general U.S. population, both Gulf War and non-Gulf War veterans had significantly lower cause-specific standardized mortality ratios (lower death rates from any given cause). Thus, deaths among both groups of veterans occurred at a rate no more than half that found in the overall U.S. population, after adjustment for age, sex, race, and year of death.

Women Gulf War veterans also showed a significant excess of deaths from all external causes, including accidents. The adjusted rate ratio was higher among female compared to male veterans. In contrast, the rate ratio for deaths from disease-related causes was almost the same among female veterans compared to male veterans. Mobilization to locations other than the Persian Gulf appears to have affected the mortality rates of women more than those of men. Women who were deployed somewhere (but who did not serve in the Gulf) had a higher, but not a significantly higher, rate of death from all causes compared to non-mobilized women, a higher rate of death from external causes, and a higher rate of death from accidents after adjustment for the type of unit, age, race, and branch of service. Female Gulf War veterans had a higher (but not significantly higher) risk of death from external causes, including accidents, compared to their female peers in the general U.S. population. The rate of death among the female Gulf War veterans was 43 percent higher than expected, whereas among other female veterans the risk was 31 percent lower than expected.

Discussion

Gulf War veterans show a significantly higher mortality compared to veterans who served during the same period but not in the Gulf War. Accidental deaths accounted for most of this difference. Neither suicide or homicide rates were elevated among Gulf War veterans. Mortality due to illness was not higher in Gulf War veterans compared to other veterans. The significant excess mortality from external causes among Gulf War veterans as compared with controls is similar to that observed in studies of veterans of earlier wars. The underlying reasons for the excess of deaths due to external causes among war veterans are not well understood.

The authors note that possible serious flaws in the design and execution of the study are an unlikely explanation for their findings. To minimize statistical variation due to sampling (taking a random sub-sample from the entire population), the study included all Gulf War veterans and almost half of all military personnel who were not sent to the Persian Gulf. The interpretation of the study findings is somewhat confounded by the possibility that military personnel who were seriously ill or recovering from major surgery would not have been deployed to the Persian Gulf area. Another limitation of the study is the reliance on death certificates rather than medical records for information on causes of death. A further possible limitation is the lack of data on potential risk factors, such as a history of smoking and/or drinking, and preexisting mental disorders.

The effect of the Gulf War on postwar mortality appears to be greater among female veterans. Both male and female veterans of the conflict had higher rates of mortality from external causes compared to controls, but the increase was greatest among women. In contrast, there was no excess of deaths from disease among either male or female Gulf War veterans. Mobilization without actual service in the Persian Gulf area had no substantial effect on the mortality of Gulf War veterans as a group. Among women, however, those who were mobilized had a higher risk of death from each category of external causes than those who were not mobilized, although the risk was not statistically significantly higher.

In summary, as compared with non-Gulf War era veterans, veterans of the conflict in the Persian Gulf had significant excesses of death from external causes (mainly accidents), but not from disease-related causes. Their risk of death remained less than half that expected in their civilian counterparts. The findings are consistent with the postwar mortality observed in veterans in previous wars.

"THE POSTWAR HOSPITALIZATION EXPERIENCE OF U.S. VETERANS OF THE PERSIAN GULF WAR" 

Reference: The New England Journal of Medicine, 335:1505-13

Date: 1996

Authors: Gregory C. Gray, M.D., M.P.H., Bruce D. Coate, M.P.H., Christy M. Anderson, Han K. Kang, Dr.P.H., S. William Berg, M.D., M.P.H., F. Stephen Wignall, M.D., James D. Knoke, Ph.D., and Elizabeth Barrett-Connor, M.D.

Background

Some veterans have reported a variety of symptoms since returning from the Gulf War. The Departments of Defense, Veterans Affairs, and Health and Human Services have responded with a number of investigations and programs that involve thorough, complete clinical evaluation for Gulf War veterans and their families. Several independent scientific and health review panels have reviewed Gulf War veterans’ health, however, thus far none has implicated specific exposures or a recognized disease process as causing the multiple symptoms nor have they identified any new illness. Using computerized hospitalization records (detailed records of a veteran’s visit to a hospital) from the Department of Defense, the authors conducted a study to determine whether Gulf War veterans were at increased risk for hospitalization after the war, as compared with veterans from the same era who did not go to the Persian Gulf.

Methods

Using a retrospective cohort approach (looking at medical data from the past) and data from Department of Defense hospitals, the authors studied hospitalizations of 547,076 veterans of the Gulf War who were serving in the Army, Navy, Marine Corps, and Air Force and 618,335 other veterans from the same era who did not serve in the Persian Gulf. Using multivariate logistic-regression models (a standard statistical approach), they analyzed risk factors (potential causes) for hospitalization both overall and for 14 broad diagnostic categories (types of illness or disease) for three periods from August 1991 through September 1993, for a total of 45 comparisons.

Results

Because of the differences between Gulf War veterans and other veterans serving in the same era, the hospitalization rates and rate ratios were adjusted for age and sex, and the multiple logistic-regression models were adjusted for all observed demographic differences between the groups. The authors also studied the data on post war separation from active duty, and disqualification from service for medical reasons, to identify potential sources of bias. Univariate analyses were performed of hospitalization for any cause and the 14 ICD-9-CM categories (standardized identifying codes) for hospitalization for each of the three postwar periods (a total of 45 comparisons).

Logistic-regression analysis showed that two years before the war, Gulf War veterans were at slightly lower risk of hospitalization for any cause compared to other veterans. However, after the war the risk of hospitalization did not differ between the two groups. There was no difference between Gulf War veterans and other veterans for risk of hospitalization from 1980 through 1988. However, from 1988 through the time just before the start of the war in August 1990, Gulf War veterans were at lower risk of hospitalization. Shortly after the war ended, the differences in this risk disappeared.

The authors studied cohort data both before and after adjustment for the prewar selection effect to determine the risk of hospitalization due to diagnoses in the 14 ICD-9-CM categories in each of the three time periods, i.e. in a total of 42 comparisons. The odds (chance) of hospitalization differed between the two cohorts in 16 of the 42 comparisons of diagnostic categories with Gulf war veterans at greater risk in five categories: neoplasms (tumors); diseases of the genitourinary system; diseases of the blood and blood-forming organs; and mental disorders.

Discussion

This study gave few surprises. The increased overall risk of hospitalization among women and health care workers was consistent with the findings of a previous study of hospitalizations. The increased rates of hospitalization after the war for conditions related to drug and alcohol use and adjustment reactions (problems with normal readjustment following any war) have been reported in other groups of combat veterans. Finally, the comparisons of separation rates were consistent with the results of other recent mortality studies that have not shown Gulf War veterans to have a higher overall or disease-related risk of death as compared to other veterans who did not serve in the Gulf War.

The authors found some differences in the risks associated with specific diagnostic categories and rates of specific diagnoses. These differences were not consistent over time and do not suggest any emerging previously unidentified illnesses associated with service in the Gulf War. Many of the observed differences between cohorts with regard to rates of diagnoses suggest that medical care for some conditions was put off until after the war.

In conclusion, the authors put together multivariate logistic-regression models for hospitalization both overall and for conditions assigned to any of 14 broad diagnostic categories in each of three postwar periods. The risk associated with 16 of these 45 comparisons differed between Gulf War veterans and other veterans. In 5 of these 16 cases, the risk of hospitalization was higher among Gulf War veterans, but the increases were inconsistent (not steady and reliable) over time and were probably due to deferred medical care, a post war baby boom, chance, or mental conditions known to be associated with war. The data suggested that veterans of the Gulf War who remained on active duty were not at increased risk for unexplained hospitalization during the 25 months after the war.