Can epidemiology clear the fog of war? Lessons from the 1990-91 Gulf War

A perspective on persistent toxicants in veterans and amyotrophic lateral sclerosis: identifying exposures determining higher ALS risk

Multiple studies indicate that United States veterans have an increased risk of developing amyotrophic lateral sclerosis (ALS) compared to civilians. However, the responsible etiological factors are unknown. In the general population, specific occupational (e.g. truck drivers, airline pilots) and environmental exposures (e.g. metals, pesticides) are associated with an increased ALS risk. As such, the increased prevalence of ALS in veterans strongly suggests that there are exposures experienced by military personnel that are disproportionate to civilians. During service, veterans may encounter numerous neurotoxic exposures (e.g. burn pits, engine exhaust, firing ranges). So far, however, there is a paucity of studies investigating environmental factors contributing to ALS in veterans and even fewer assessing their exposure using biomarkers. Herein, we discuss ALS pathogenesis in relation to a series of persistent neurotoxicants (often emitted as mixtures) including: chemical elements, nanoparticles and lipophilic toxicants such as dioxins, polycyclic aromatic hydrocarbons and polychlorinated biphenyls. We propose these toxicants should be directly measured in veteran central nervous system tissue, where they may have accumulated for decades. Specific toxicants (or mixtures thereof) may accelerate ALS development following a multistep hypothesis or act synergistically with other service-linked exposures (e.g. head trauma/concussions). Such possibilities could explain the lower age of onset observed in veterans compared to civilians. Identifying high-risk exposures within vulnerable populations is key to understanding ALS etiopathogenesis and is urgently needed to act upon modifiable risk factors for military personnel who deserve enhanced protection during their years of service, not only for their short-term, but also long-term health.

The association of pre-war medical conditions to Gulf War Illness

AIMS

Gulf War Illness (GWI) remains a significant health concern for many veterans. The relation of pre-war health conditions and symptoms to GWI could aid in developing a more accurate case definition of GWI. The objective of this study was to investigate pre-war predictors of GWI in a population-based sample of Gulf War veterans using two definitions of GWI.

MAIN METHODS

Data come from the 1995-1997 National Health Survey of Persian Gulf War Era Veterans, a survey of a representative sample of deployed and non-deployed US veterans. Using two definitions of GWI (CDC/Kansas and a newly developed 3-domain definition), we conducted a series of multivariable logistic regression analyses to assess the associations of demographic, lifestyle factors, and pre-war medical conditions and symptoms to subsequent GWI.

KEY FINDINGS

All pre-war symptom predictor domains were significantly and positively associated with GWI using a new 3-domain definition with aORs for individual domains ranging from 2.17 (95% CI = 1.99-2.38) for dermatologic conditions to 3.06 (95% CI = 2.78-3.37) for neurological conditions. All symptom predictor domains were associated with significantly increased likelihood of GWI using the CDC/Kansas definition, with aORs ranging from 2.54 (95% CI = 2.31-2.81) for inflammatory conditions to 3.22 (95% CI = 2.94-3.55) for neurological conditions. These estimates were attenuated but remained significant after inclusion of all significant symptom predictor domains.

SIGNIFICANCE

Results from this study suggest that demographic/lifestyle factors and pre-war medical conditions are strong predictors of GWI. Additional research is needed to confirm these findings, and to clarify the unique characteristics of this common, but still poorly understood illness.

Emerging role of glutamate in the pathophysiology and therapeutics of Gulf War illness

Gulf War illness (GWI) is a chronic and multi-symptomatic disorder affecting veterans who served in the Gulf War. The commonly reported symptoms in GWI veterans include mood problems, cognitive impairment, muscle and joint pain, migraine/headache, chronic fatigue, gastrointestinal complaints, skin rashes, and respiratory problems. Neuroimaging studies have revealed significant brain structure alterations in GWI veterans, including subcortical atrophy, decreased volume of the hippocampus, reduced total grey and white matter, and increased brain white matter axial diffusivity. These brain changes may contribute to or increase the severities of the GWI-related symptoms. Epidemiological studies have revealed that neurotoxic exposures and stress may be significant contributors to the development of GWI. However, the mechanism underlying how the exposure and stress could contribute to the multi-symptomatic disorder of GWI remains unclear. We and others have demonstrated that rodent models exposed to GW-related agents and stress exhibited higher extracellular glutamate levels, as well as impaired structure and function of glutamatergic synapses. Restoration of the glutamatergic synapses ameliorated the GWI-related pathological and behavioral deficits. Moreover, recent studies showed that a low-glutamate diet reduced multiple symptoms in GWI veterans, suggesting an important role of the glutamatergic system in GWI. Currently, growing evidence has indicated that abnormal glutamate neurotransmission may contribute to the GWI symptoms. This review summarizes the potential roles of glutamate dyshomeostasis and dysfunction of the glutamatergic system in linking the initial cause to the multi-symptomatic outcomes in GWI and suggests the glutamatergic system as a therapeutic target for GWI.

Neuropsychological, Neurocognitive, Vestibular, and Neuroimaging Correlates of Exposure to Repetitive Low-Level Blast Waves: Evidence From Four Nonoverlapping Samples of Canadian Breachers

INTRODUCTION

We assessed the utility of a battery of neuropsychological, neurocognitive, physiological (balance, ataxia, postural tremor), and neuroimaging measures for studying the effects of blast waves in breachers-a population repeatedly exposed to low-level blast during military training and operations.

MATERIALS AND METHODS

Data were collected from four nonoverlapping samples, in the course of similarly structured 4-day breacher training exercises in successive years involving a combination of indoor and outdoor blast events. In all cases, self-report and neuropsychological measures were administered once at baseline (i.e., 1 day before the start of training). In years 1-2, neurocognitive and physiological measures were administered daily before and after training. In years 3-4, neurocognitive data were collected once at baseline. In Year 4, we introduced 3 modifications to our design. First, in addition to breachers, we also collected data from sex-and age-matched military controls at the same time points. Second, we assessed balance, ataxia, and postural tremor immediately following blast exposure "in the field," enabling us to quantify its acute effects. Third, structural magnetic resonance imaging (MRI) scans were acquired before and after the 4-day training exercise to explore differences between breachers and controls at baseline, as well as possible training-related changes using voxel-based morphometry. These design modifications were made to enable us to test additional hypotheses in the context of the same training exercise.

RESULTS

At baseline, scores on the "Rivermead Post Concussion Symptoms Questionnaire," "RAND SF-36" (physical functioning, role limitation due to physical health, social functioning, energy/fatigue, general health), and "Short Musculoskeletal Function Questionnaire" distinguished breachers from controls. Also at baseline, the MRI data revealed that there was greater regional gray matter volume in controls compared to breachers in the right superior frontal gyrus. Balance, ataxia, and postural tremor did not exhibit sensitivity to the acute effects of blast in the field, nor did neurocognitive measures to its cumulative or daily effects.

CONCLUSION

Our exploratory results suggest that self-report neuropsychological measures and structural MRI hold promise as sensitive measures for quantifying the long-term, cumulative effects of blast exposure in breachers. We discuss the limitations of our study and the need for prospective longitudinal data for drawing causal inferences regarding the impact of blast exposure on breachers' health and performance.

Challenges to and facilitators of occupational epidemiology research in the UK

This study investigated the challenges and facilitators of occupational epidemiology (OE) research in the UK, and evaluated the impact of these challenges. Semi-structured in-depth interviews with leading UK-based OE researchers, and a survey of UK-based OE researchers were conducted. Seven leading researchers were interviewed, and there were 54 survey respondents. Key reported challenges for OE were diminishing resources during recent decades, influenced by social, economic and political drivers, and changing fashions in research policy. Consequently, the community is getting smaller and less influential. These challenges may have negatively affected OE research, causing it to fail to keep pace with recent methodological development and impacting its output of high-quality research. Better communication with, and support from other researchers and relevant policy and funding stakeholders was identified as the main facilitators to OE research. Many diseases were initially discovered in workplaces, as these make exceptionally good study populations to accurately assess exposures. Due to the decline of manufacturing industry, there is a perception that occupational diseases are now a thing of the past. Nevertheless, new occupational exposures remain under-evaluated and the UK has become reliant on overseas epidemiology. This has been exacerbated by the decline in the academic occupational medicine base. Maintaining UK-based OE research is hence necessary for the future development of occupational health services and policies for the UK workforce.

Helpful ways providers can communicate about persistent medically unexplained physical symptoms

BACKGROUND

Communication between patients and providers about persistent "medically unexplained" physical symptoms (MUS) is characterized by discordance. While the difficulties are well documented, few studies have examined effective communication. We sought to determine what veterans with Gulf War Illness (GWI) perceive as the most helpful communication from their providers. Veterans with GWI, a type of MUS, have historically had complex relationships with medical providers. Determining effective communication for patients with particularly complex relationships may help identify the most critical communication elements for all patients with MUS.

METHODS

Two hundred and-ten veterans with GWI were asked, in a written questionnaire, what was the most useful thing a medical provider had told them about their GWI. Responses were coded into three categories with 10 codes.

RESULTS

The most prevalent helpful communication reported by patients was when the provider offered acknowledgement and validation (N = 70). Specific recommendations for managing GWI or its symptoms (N = 48) were also commonly reported to be helpful. In contrast, about a third of the responses indicated that nothing about the communication was helpful (N = 63). There were not differences in severity of symptoms, disability or healthcare utilization between patients who found acknowledgement and validation, specific recommendations or nothing helpful.

CONCLUSIONS

Previous research has documented the discord between patients and providers regarding MUS. This study suggests that most patients are able to identify something helpful a provider has said, particularly acknowledgement and validation and specific treatment recommendations. The findings also highlight missed communication opportunities with a third of patients not finding anything helpful.

Military veteran engagement with mental health and well-being services: a qualitative study of the role of the peer support worker

Background: Many UK military veterans experiencing mental health and well-being difficulties do not engage with support services to get the help they need. Some mental health clinics employ Peer Support Workers (PSWs) to help veteran patients engage, however it is not known how the role influences UK veteran engagement.Aims: To gain insight into the role of peer support in UK veteran engagement with mental health and well-being services.Method: A qualitative study based on 18 semi-structured interviews with veterans, PSWs and mental health clinicians at a specialist veteran mental health and well-being clinic in Scotland.Results: Four themes of the PSW role as positive first impression, understanding professional friend, helpful and supportive connector, and an open door were identified across all participants. The PSWs' military connection, social and well-being support and role in providing veterans with an easily accessible route to dis-engage and re-engage with the service over multiple engagement attempts were particularly crucial.Conclusions: The Peer Support role enhanced veteran engagement in the majority of instances. Study findings mirrored existing peer support literature, provided new evidence in relation to engaging UK veterans, and made recommendations for future veteran research and service provision.

Prospective Analysis of Premilitary Mental Health, Somatic Symptoms, and Postdeployment Postconcussive Symptoms

OBJECTIVES

Many recent studies of service members returning from deployment have focused on the health impacts of mild traumatic brain injury (mTBI), including persistent postconcussive symptoms (PCS). However, cross-sectional study designs have made it difficult to understand the role of mental health in the etiology of persistent PCS.

METHODS

Participants were 3319 military personnel (primarily men [90%] of 25-34 years [54%]) who had completed health surveys at basic training and after deployment, on average, 4.6 years later. Negative binomial regression was used to assess the association of PCS with demographic covariates, premilitary mental health and somatic symptoms, combat experiences and mTBI during deployment, in addition to postdeployment mental health and non-PCS somatic symptoms.

RESULTS

Premilitary mental health and somatic symptoms predicted PCS even when adjusting for other variables, yielding an elevated incidence rate ratio (IRR) for posttraumatic stress disorder (PTSD; IRR = 1.23, 95% confidence interval [CI] = 1.06-1.41) and somatic symptoms (mild versus minimal somatic symptoms: IRR = 1.43, 95% CI = 1.31-1.55; moderate/severe versus minimal somatic symptoms: IRR = 1.69, 95% CI = 1.43-2.06), but not for depressive symptoms. When postdeployment mental health and somatic symptom measures were added to the model, the effect of premilitary somatic symptoms remained significant.

CONCLUSIONS

Findings point to potential etiological contributions of premilitary characteristics, particularly a tendency to experience somatic symptoms and PTSD, as well as mTBI and combat experiences, to the development of PCS. PCS were also strongly related to concurrent postdeployment mental health.

Long-term disability associated with war-related experience among Vietnam veterans: retrospective cohort study

Background:

Recent combat operations have involved large numbers of personnel. Long-term health effects of military deployment remain largely unknown.

Objectives:

To examine patterns and trends in long-term disability among combat veterans and to relate disability to aspects of wartime experience.

Participants:

A total of 60,228 Australian military personnel deployed between 1962 and 1975 during the Vietnam War, and 82,877 military personnel who were not deployed overseas.

Outcome Measures:

Accepted physician-assessed disability claims were evaluated over follow-up periods up to 50 years after deployment, and compared with age-matched controls. Multivariable analysis was used to examine differences by service branch, rank, age, and deployment duration.

Results:

The steepest rise in disability incidence was observed among Vietnam veterans starting in the 1990s, around 20–30 years after deployment for most veterans. After 1994, when Statements of Principles were introduced to guide evaluation of disability claims, the hazard ratio for disability incidence was 1.53 (95% confidence interval, 1.32–1.77) compared with the prior period. By January 2011, after an average follow-up of 42.5 years, 69.7% (95% confidence interval, 69.4%–70.1%) of veterans had at least 1 war-related disability. Many veterans had multiple disabilities, with leading causes being eye and ear disorders (48.0%), mental health conditions (47.9%), and musculoskeletal disorders (18.4%). For specific categories of disability, relative risks for accepted claims among veterans compared with controls were highest for mental health disorders, at 22.9 (21.9–24.0) and lowest for injuries, at 1.5 (1.4–1.6) with a relative risk for any disability of 3.7 (3.7–3.8). Veterans with service of >1 year were 2.5 (2.2–2.7) times more likely to have a mental health disability than those who served <100 days, and 2.3 (2.1–2.5) times more likely to have other disabilities.

Conclusions:

Long-term effects of deployment into military conflicts are substantial, and likelihood of war-related disability is associated with service history. If similar patterns follow from more recent conflicts, significant additional resources will be needed to prevent and treat long-term health conditions among veterans.

Trauma, post-traumatic stress disorder and psychiatric disorders in a middle-income setting: prevalence and comorbidity

BACKGROUND

Most studies of post-traumatic stress disorder (PTSD) in low- and middle-income countries (LMICs) have focused on 'high-risk' populations defined by exposure to trauma.

AIMS

To estimate the prevalence of post-traumatic stress disorder (PTSD) in a LMIC, the conditional probability of PTSD given a traumatic event and the strength of associations between traumatic events and other psychiatric disorders.

METHOD

Our sample contained a mix of 3995 twins and 2019 non-twins. We asked participants about nine different traumatic exposures, including the category 'other', but excluding sexual trauma.

RESULTS

Traumatic events were reported by 36.3% of participants and lifetime PTSD was present in 2.0%. Prevalence of non-PTSD lifetime diagnosis was 19.1%. Of people who had experienced three or more traumatic events, 13.3% had lifetime PTSD and 40.4% had a non-PTSD psychiatric diagnosis.

CONCLUSIONS

Despite high rates of exposure to trauma, this population had lower rates of PTSD than high-income populations, although the prevalence might have been slightly affected by the exclusion of sexual trauma. There are high rates of non-PTSD diagnoses associated with trauma exposure that could be considered in interventions for trauma-exposed populations. Our findings suggest that there is no unique relationship between traumatic experiences and the specific symptomatology of PTSD.

Cancer incidence in Dutch Balkan veterans

Suspicion has been raised about an increased cancer risk among Balkan veterans because of alleged exposure to depleted uranium. The authors conducted a historical cohort study to examine cancer incidence among Dutch Balkan veterans. Male military personnel (n=18,175, median follow-up 11 years) of the Army and Military Police who had been deployed to the Balkan region (1993-2001) was compared with their peers not deployed to the Balkans (n=135,355, median follow-up 15 years) and with the general Dutch population of comparable age and sex. The incidence of all cancers and 4 main cancer subgroups was studied in the period 1993-2008. The cancer incidence rate among Balkan deployed military men was 17% lower than among non-Balkan deployed military men (hazard ratio 0.83 (95% confidence interval 0.69, 1.00)). For the 4 main cancer subgroups, hazard ratios were statistically non-significantly below 1. Also compared to the general population cancer rates were lower in Balkan deployed personnel (standardised incidence rate ratio (SIR) 0.85 (0.73, 0.99). The SIR for leukaemia was 0.63 (0.20, 1.46). The authors conclude that earlier suggestions of increased cancer risks among veterans are not supported by empirical data. The lower risk of cancer might be explained by the 'healthy warrior effect'.

Complex factors in the etiology of Gulf War illness: wartime exposures and risk factors in veteran subgroups

BACKGROUND

At least one-fourth of U.S. veterans who served in the 1990-1991 Gulf War are affected by the chronic symptomatic illness known as Gulf War illness (GWI). Clear determination of the causes of GWI has been hindered by many factors, including limitations in how epidemiologic studies have assessed the impact of the complex deployment environment on veterans' health.

OBJECTIVE

We sought to address GWI etiologic questions by evaluating the association of symptomatic illness with characteristics of veterans' deployment.

METHODS

We compared veteran-reported wartime experiences in a population-based sample of 304 Gulf War veterans: 144 cases who met preestablished criteria for GWI and 160 controls. Veteran subgroups and confounding among deployment variables were considered in the analyses.

RESULTS

Deployment experiences and the prevalence of GWI differed significantly by veterans' location in theater. Among personnel who were in Iraq or Kuwait, where all battles took place, GWI was most strongly associated with using pyridostigmine bromide pills [odds ratio (OR) = 3.5; 95% confidence interval (CI): 1.7, 7.4] and being within 1 mile of an exploding SCUD missile (OR = 3.1; 95% CI: 1.5, 6.1). For veterans who remained in support areas, GWI was significantly associated only with personal pesticide use, with increased prevalence (OR = 12.7; 95% CI: 2.6, 61.5) in the relatively small subgroup that wore pesticide-treated uniforms, nearly all of whom also used skin pesticides. Combat service was not significantly associated with GWI.

CONCLUSIONS

Findings support a role for a limited number of wartime exposures in the etiology of GWI, which differed in importance with the deployment milieu in which veterans served.

What are the consequences of deployment to Iraq and Afghanistan on the mental health of the UK armed forces? A cohort study

BACKGROUND

Concerns have been raised about the psychological effect of continued combat exposure and of repeated deployments. We examined the consequences of deployment to Iraq and Afghanistan on the mental health of UK armed forces from 2003 to 2009, the effect of multiple deployments, and time since return from deployment.

METHODS

We reassessed the prevalence of probable mental disorders in participants of our previous study (2003-05). We also studied two new randomly chosen samples: those with recent deployment to Afghanistan, and those who had joined the UK armed forces since April, 2003, to ensure that the final sample continued to be representative of the UK armed forces. Between November, 2007, and September, 2009, participants completed a questionnaire about their deployment experiences and health outcomes.

FINDINGS

9990 (56%) participants completed the study questionnaire (8278 regulars, 1712 reservists). The prevalence of probable post-traumatic stress disorder was 4.0% (95% CI 3.5-4.5; n=376), 19.7% (18.7-20.6; n=1908) for symptoms of common mental disorders, and 13.0% (12.2-13.8; n=1323) for alcohol misuse. Deployment to Iraq or Afghanistan was significantly associated with alcohol misuse for regulars (odds ratio 1.22, 95% CI 1.02-1.46) and with probable post-traumatic stress disorder for reservists (2.83, 1.23-6.51). Regular personnel in combat roles were more likely than were those in support roles to report probable post-traumatic stress disorder (1.87, 1.26-2.78). There was no association with number of deployments for any outcome. There was some evidence for a small increase in the reporting of probable post-traumatic stress disorder with time since return from deployment in regulars (1.13, 1.03-1.24).

INTERPRETATION

Symptoms of common mental disorders and alcohol misuse remain the most frequently reported mental disorders in UK armed forces personnel, whereas the prevalence of probable post-traumatic stress disorder was low. These findings show the importance of continued health surveillance of UK military personnel.

FUNDING

UK Ministry of Defence.

Cyanobacteria and BMAA exposure from desert dust: a possible link to sporadic ALS among Gulf War veterans

Veterans of the 1990-1991 Gulf War have been reported to have an increased incidence of amyotrophic lateral sclerosis (ALS) compared to personnel who were not deployed. An excess of ALS cases was diagnosed in Gulf War veterans younger than 45 years of age. Increased ALS among Gulf War veterans appears to be an outbreak time-limited to the decade following the Gulf War. Seeking to identify biologically plausible environmental exposures, we have focused on inhalation of cyanobacteria and cyanotoxins carried by dust in the Gulf region, particularly Qatar. Cyanobacterial crusts and mats are widespread in the deserts of Qatar, occupying up to 56% of the available area in some microhabitats. These cyanobacterial crusts, which help bind the desert sands, are dormant throughout most of the year, but during brief spring rains actively photosynthesize. When disturbed by vehicular traffic or other military activities, the dried crusts and mats can produce significant dust. Using HPLC/FD, an amino acid analyzer, UPLC/MS, and triple quadrupole LC/MS/MS we find that the dried crusts and mats contain neurotoxic cyanobacterial toxins, including beta-N-methylamino-L-alanine (BMAA) and 2,4 diaminobutyric acid (DAB). If dust containing cyanobacteria is inhaled, significant exposure to BMAA and other cyanotoxins may occur. We suggest that inhalation of BMAA, DAB, and other aerosolized cyanotoxins may constitute a significant risk factor for the development of ALS and other neurodegenerative diseases.

Prevalence Estimates of Combat-Related PTSD: A Critical Review

The aim of the present study was to provide a critical review of prevalence estimates of combat-related post-traumatic stress disorder (PTSD) among military personnel and veterans, and of the relevant factors that may account for the variability of estimates within and across cohorts, including methodological and conceptual factors accounting for differences in prevalence rates across nations, conflicts/wars, and studies. MEDLINE and PsycINFO databases were examined for literature on combat-related PTSD. The following terms were used independently and in combinations in this search: PTSD, combat, veterans, military, epidemiology, prevalence. The point prevalence of combat-related PTSD in US military veterans since the Vietnam War ranged from approximately 2% to 17%. Studies of recent conflicts suggest that combat-related PTSD afflicts between 4% and 17% of US Iraq War veterans, but only 3-6% of returning UK Iraq War veterans. Thus, the prevalence range is narrower and tends to have a lower ceiling among combat veterans of non-US Western nations. Variability in prevalence is likely due to differences in sampling strategies; measurement strategies; inclusion and measurement of the DSM-IV clinically significant impairment criterion; timing and latency of assessment and potential for recall bias; and combat experiences. Prevalence rates are also likely affected by issues related to PTSD course, chronicity, and comorbidity; symptom overlap with other psychiatric disorders; and sociopolitical and cultural factors that may vary over time and by nation. The disorder represents a significant and costly illness to veterans, their families, and society as a whole. Further carefully conceptualized research, however, is needed to advance our understanding of disorder prevalence, as well as associated information on course, phenomenology, protective factors, treatment, and economic costs.

Depleted uranium: properties, military use and health risks

This article describes uranium and depleted uranium (DU), their similar isotopic compositions, how DU arises, its use in munitions and armour-proofing, and its pathways for human exposures. Particular attention is paid to the evidence of DU's health effects from cell and animal experiments and from epidemiology studies. It is concluded that a precautionary approach should be adopted to DU and that there should be a moratorium on its use by military forces. International efforts to this end are described.

Delayed-onset post-traumatic stress disorder among war veterans in primary care clinics

BACKGROUND

Only limited empirical data support the existence of delayed-onset post-traumatic stress disorder (PTSD).

AIMS

To expand our understanding of delayed-onset PTSD prevalence and phenomenology.

METHOD

A cross-sectional, epidemiological design (n = 747) incorporating structured interviews to obtain relevant information for analyses in a multisite study of military veterans.

RESULTS

A small percentage of veterans with identified current PTSD (8.3%, 7/84), current subthreshold PTSD (6.9%, 2/29), and lifetime PTSD only (5.4%, 2/37) met criteria for delayed onset with PTSD symptoms initiating more than 6 months after the index trauma. Altogether only 0.4% (3/747) of the entire sample had current PTSD with delayed-onset symptoms developing more than 1 year after trauma exposure, and no PTSD symptom onset was reported more than 6 years post-trauma.

CONCLUSIONS

Retrospective reports of veterans reveal that delayed-onset PTSD (current, subthreshold or lifetime) is extremely rare 1 year post-trauma, and there was no evidence of PTSD symptom onset 6 or more years after trauma exposure.

The Deployment Health Surveillance Program: vision and challenges of health surveillance for Australian military cohorts

The Australian Government has supported the establishment of a Deployment Health Surveillance Program for the Australian Defence Force. Although some health screening mechanisms already exist for Australian Defence Force personnel, until now health data have been used largely for clinical management at an individual level and have not been aggregated to identify trends in health and risk factors in the shorter or longer term. We identify challenges for and potential benefits of health surveillance in the military context, describe features of the Program and progress to date. Retrospective and cross-sectional projects based on deployments to the Near North Area of Influence since 1997 are under way. A planned prospective model of health surveillance for those deploying to the Middle East promises more timely attention to any emerging health problems for military personnel and veterans.

Does prior psychological health influence recall of military experiences? a prospective study

In a prospective study, we evaluated pre- and postdeployment psychological health on recall of risk factors to assess recall bias. Measures of the General Health Questionnaire (GHQ), PTSD Checklist (PCL), and symptom clusters from the PCL were obtained from 681 UK military personnel along with information on traumatic and protective risk factors. Postdeployment psychological health was more important in explaining recall of traumatic experiences than predeployment psychological health. Predeployment intrusive cluster scores were highly associated with traumatic exposures. Postdeployment, but not predeployment GHQ showed small effects for most risk factors. With the exception of intrusive thoughts, there is insufficient evidence to suggest predeployment psychological status would be useful in correcting for recall bias in subsequent cross-sectional studies.

Multiple vaccinations, health, and recall bias within UK armed forces deployed to Iraq: cohort study

OBJECTIVE

To assess the relation between self reported number of vaccinations received and health, and between numbers of vaccinations recorded from individuals' medical records and health.

DESIGN

First phase of a cohort study.

SETTING

UK armed forces personnel.

PARTICIPANTS

4882 randomly selected military personnel deployed to Iraq since 2003 and a subset of 378 whose vaccination records were accessed.

MAIN OUTCOME MEASURES

Psychological distress, fatigue, symptoms of post-traumatic stress disorder, health perception, and multiple physical symptoms.

RESULTS

Personnel who reported receiving two or more vaccinations on a single day were more likely to report symptoms of fatigue (adjusted risk ratio 1.17, 95% confidence interval 1.05 to 1.30), show caseness according to the general health questionnaire (1.31, 1.13 to 1.53), and have multiple physical symptoms (1.32, 1.08 to 1.60). These associations were no longer significant when number of vaccinations recorded in individuals' medical records was used as the independent variable.

CONCLUSIONS

Multiple vaccinations given to personnel in the UK armed forces in preparation for deployment to Iraq are not associated with adverse health consequences when vaccinations are recorded objectively from medical records. Adverse health consequences associated with self reported multiple vaccinations could be explained by recall bias.

Memory consistency for traumatic events in Dutch soldiers deployed to Iraq

Retrospective accounts of traumatic events are consistently associated with symptoms of post-traumatic stress disorder (PTSD). This has often been interpreted as causal impact of such events on psychological functioning, but recent studies suggest that the causal direction is (partly) reversed: high levels of PTSD symptoms may be associated with amplified recollections of precipitating traumatic events. The aim of this prospective study was to index the consistency with which Dutch Army soldiers reported traumatic stressors and nontraumatic stressors on their deployment to Iraq, and to examine to what extent PTSD symptoms and pre-existing reporting biases, such as that arising from neuroticism, affect memory inconsistency. Retrospective accounts of stressors were highly variable over time. Individuals with higher levels of PTSD symptoms and neuroticism, lower levels of extraversion, and fewer prior missions, were more prone to increased reporting over time.

Deployment-related stress and trauma in Dutch soldiers returning from Iraq. Prospective study

BACKGROUND

Some questionnaire studies have shown increased mental health problems, including probable post-traumatic stress disorder (PTSD), in soldiers deployed to Iraq.

AIMS

To test prospectively whether such problems change over time and whether questionnaires provide accurate estimates of deployment-related PTSD compared with a clinical interview.

METHODS

Dutch infantry troops from three cohorts completed questionnaires before deployment to Iraq (n=479), and about 5 months (n=382, 80%) and 15 months (n=331, 69%) thereafter. Post-traumatic stress disorder was evaluated by questionnaire and clinical interview.

RESULTS

There were no group changes for general distress symptoms. The rates of PTSD for each cohort were 21, 4 and 6% based on questionnaires at 5 months. The deployment-related rates of PTSD based on the clinical interview were 4, 3 and 3%.

CONCLUSIONS

There was a specific effect of deployment on mental health for a small minority. Questionnaires eliciting stress symptoms gave substantial overestimations of the rate of PTSD.

Gulf War Illness: lessons from medically unexplained symptoms

Service in the Persian Gulf in 1991 is associated with increased reporting of symptoms and distress in a proportion of those who served there. Yet despite clear evidence of an increase in symptom burden and a decrease in well being, exhaustive clinical and laboratory based scientific research has failed to document many reproducible biomedical abnormalities in this group. Likewise, there has been no evidence of an increase in disease related mortality. Formal psychiatric disorders are twice as common in Gulf War veterans, as might be expected in the aftermath of any conflict, but this too is insufficient to explain the ill-health observed. Many service personnel who returned unwell believe that they have Gulf War Syndrome, and that their ill-health is due to exposures that they encountered in theatre. Research on multiple exposures to date has not generated a plausible aetiological mechanism for veterans' ill-health. Even if medical research has failed to provide a satisfactory explanation, it remains the case that many of those affected continue to be unwell and disabled some 15 years after returning from combat. For this reason, it is time that more attention is given to developing effective interventions to relieve their ill-health and distress. In this review we discuss the importance of the wider social context, individual illness beliefs and attributions and go on to outline a model of continuing ill-health in Gulf veterans. The review concludes with some suggestions for future research priorities, in particular the need for further qualitative studies to further our understanding of the illness, in order that better treatments may be developed.

Hazardous or harmful alcohol use in Royal Australian Navy veterans of the 1991 Gulf War: identification of high risk subgroups

Elevated alcohol use disorders have been observed in 1991 Gulf War veterans from a variety of countries. This study used a self-report instrument, the Alcohol Use Disorders Identification Test (AUDIT), to ascertain whether any subgroups of 1232 male Royal Australian Navy (RAN) Gulf War veterans were at higher risk of hazardous or harmful alcohol use. Recursive partitioning/classification and regression tree (CART) analysis, followed by logistic regression, found five subgroups among the veterans, with differing risks of AUDIT caseness. The highest risk subgroup comprised current smokers. The other two high risk groups both consisted of former or never smokers of lower rank who were (1) not married, or (2) married, with a current diagnosis of major depression. The above subgroups were over three times as likely to exhibit AUDIT caseness than those who were former or never smokers of higher rank. The findings have important implications for effective development of public health initiatives designed to encourage safe alcohol use among veterans.

The challenges of exposure assessment in health studies of Gulf War veterans

A variety of exposures have been investigated in Gulf War veterans' health studies. These have most commonly been by self-report in a postal questionnaire but modelling and bio-monitoring have also been employed. Exposure assessment is difficult to do well in studies of any workplace environment. It is made more difficult in Gulf War studies where there are a number and variety of possible exposures, no agreed metrics for individual exposures and few contemporary records associating the exposure with an individual. In some studies, the exposure assessment was carried out some years after the war and in the context of media interest. Several studies have examined different ways to test the accuracy of exposure reporting in Gulf War cohorts. There is some evidence from Gulf War studies that self-reported exposures were subject to recall bias but it is difficult to assess the extent. Occupational exposure-assessment methodology can provide insights into the exposure-assessment process and how to do it well. This is discussed in the context of the Gulf War studies. Alternative exposure-assessment methodologies are presented, although these may not be suitable for widespread use in veteran studies. Due to the poor quality of and accessibility of objective military exposure records, self-assessed exposure questionnaires are likely to remain the main instrument for assessing the exposure for a large number of veterans. If this is to be the case, then validation methods with more objective methods need to be included in future study designs.

Immunological dysfunction, vaccination and Gulf War illness

One candidate cause of Gulf War illness is vaccination against infectious diseases including medical counter-measures against biological weapons. One influential theory has suggested that such mass-vaccination caused a shift in immune response to a Type 2 cytokine pattern (Th2), which it was suggested was accompanied by a chronic fatigue syndrome-like illness. This article critically appraises this theory. We start by examining epidemiological evidence, which indicates that single vaccines are unlikely to be a substantial cause of Gulf War illness, but that there was a modest relationship with multiple vaccines, which was strongest in those vaccinated while deployed to the Gulf. These relationships may be affected by recall bias. We conclude by examining the results of immunological studies carried out in veterans or in a relevant setting in vitro. The balance of evidence from immunological studies on veterans returning from the War, including those developing multi-symptom illness, is that the immune response has not become polarized towards Th2. In summary, the epidemiological evidence for a multiple vaccine effect on Gulf War-related illness remains a potentially important aetiological lead, but mechanistic studies available at this stage do not identify any immunological basis for it.

Symptoms, ill-health and quality of life in a support group of Porton Down veterans

BACKGROUND

There has been a Human Volunteer Programme at the British chemical weapons research facility at Porton Down since the First World War, in which some of the participants were exposed to chemical warfare agents.

AIM

To identify any striking specific morbidity patterns in members of the Porton Down Veterans Support Group (PDVSG).

METHODS

A self-completed postal questionnaire was prepared including health immediately after the visits to Porton Down, subsequent diagnoses and hospital admissions, symptoms in, and after, the first 5 years after the visits, fatigue symptoms and current quality of life, measured using the SF-36.

RESULTS

Responses were received from 289 of 436 (66%). Results reported here relate to 269 male respondents of mean age 66.8 years. Sixty-six per cent reported their first visit to Porton Down in the 1950s. The most common diagnoses or hospital admissions reported were diseases of the circulatory system. In the first 5 years after their visits the most common symptoms were headache, irritability or outbursts of anger and feeling un-refreshed after sleep. In the later period, most common symptoms were fatigue, feeling un-refreshed after sleep and sleeping difficulties. Sixty-five per cent met the definition for a case of 'fatigue'. Current quality of life dimensions were consistently lower than age-specific estimates from general population samples.

CONCLUSIONS

Members of the PDVSG responding to this survey reported poorer quality of life than the general population. Despite there being no clear pattern of specific morbidities, we cannot rule out ill-health being potentially associated with past experience at Porton Down.

The health of UK military personnel who deployed to the 2003 Iraq war: a cohort study

BACKGROUND

Concerns have been raised about the mental and physical health of UK military personnel who deployed to the 2003 war in Iraq and subsequent tours of duty in the country.

METHODS

We compared health outcomes in a random sample of UK armed forces personnel who were deployed to the 2003 Iraq war with those in personnel who were not deployed. Participants completed a questionnaire covering the nature of the deployment and health outcomes, which included symptoms of post-traumatic stress disorder, common mental disorders, general wellbeing, alcohol consumption, physical symptoms, and fatigue.

FINDINGS

The participation rate was 62.3% (n=4722) in the deployed sample, and 56.3% (n=5550) in the non-deployed sample. Differences in health outcomes between groups were slight. There was a modest increase in the number of individuals with multiple physical symptoms (odds ratio 1.33; 95% CI 1.15-1.54). No other differences between groups were noted. The effect of deployment was different for reservists compared with regulars. In regulars, only presence of multiple physical symptoms was weakly associated with deployment (1.32; 1.14-1.53), whereas for reservists deployment was associated with common mental disorders (2.47, 1.35-4.52) and fatigue (1.78; 1.09-2.91). There was no evidence that later deployments, which were associated with escalating insurgency and UK casualties, were associated with poorer mental health outcomes.

INTERPRETATION

For regular personnel in the UK armed forces, deployment to the Iraq war has not, so far, been associated with significantly worse health outcomes, apart from a modest effect on multiple physical symptoms. There is evidence of a clinically and statistically significant effect on health in reservists.

The burden of psychological symptoms in UK Armed Forces

OBJECTIVE

To assess the prevalence of psychological symptoms during periods of relatively low deployment activity and the factors associated with each psychological health outcome.

METHODS

A survey of 4500 randomly selected UK service personnel was carried out in 2002. The questionnaire included the General Health Questionnaire (GHQ-12), the post-traumatic stress disorder checklist (PCL), 15 symptoms and an assessment of alcohol intake.

RESULTS

A total of 20% were above cut-offs for GHQ-12, 15% for symptoms, 12% for alcohol intake and 2% for PCL. Gender, age, excessive drinking and smoking were independently associated with most outcomes of interest. Number of deployments was independently associated with multiple symptoms and excessive drinking. High post-traumatic stress disorder score was more frequent in the Army and in lower ranks.

CONCLUSIONS

Psychological symptoms are highly prevalent in UK Armed Forces. Many risk factors are associated with measures of psychological ill-health.

Resolving Disputes About Toxicological Risks During Military Conflict

In the last 15 years, the US and UK have fought two major wars in the Persian Gulf region. Controversy has arisen over the nature and causes of health problems among military veterans of these two wars. Toxic exposures have been hypothesised to cause the majority of the long-term health problems experienced by veterans of the 1991 Gulf War. The assessment of these toxic exposures and the resolution of controversy about their health effects provide a unique case study for understanding how toxicological disputes are settled in the US. Neither clinical examination of ill war veterans nor scientific research studies have been sufficient to answer contentious questions about toxic exposures. Numerous expert review panels have also been unable to resolve these controversies except for the US National Academy of Sciences Institute of Medicine (IOM). The IOM has conducted exhaustive and independent investigations based on peer-reviewed scientific literature related to potential health risks during the two Gulf Wars. In four recent studies, IOM committees identified a wide range of previously documented illnesses associated with common occupational and environmental exposures after considering thousands of relevant publications; however, they did not identify a new medical syndrome or a specific toxic exposure that caused widespread health problems among Gulf War veterans. These IOM studies have, therefore, added little to our basic knowledge of environmental hazards because most of the health effects were well known. Nevertheless, this expert review process, which is on-going, has been generally acceptable to a wide range of competing interests because the findings of the IOM have been perceived as scientifically credible and independent, and because none of the postulated toxicological risks have been completely ruled-out as possible causes of ill health among veterans.