Prescription Stimulants and PTSD Among U.S. Military Service Members.

Posttraumatic stress disorder (PTSD) is a prevalent condition among military service members and civilians who have experienced traumatic events. Stimulant use has been postulated to increase the risk of incident PTSD; however, research in this area is lacking. In this study, the association between receipt of prescription stimulants and PTSD was examined in a secondary analysis among active duty U.S. military members (n = 25,971), participating in the Millennium Cohort Study, who completed a baseline (2001-2003) and two follow-up surveys (between 2004-2008). Prescription stimulant data were obtained from the military Pharmacy Data Transaction Service. PTSD was assessed using the PTSD Checklist-Civilian Version and incident PTSD was defined as meeting the criteria at follow-up among those who did not have a history of PTSD at baseline. Overall, 1,215 (4.7%) persons developed new-onset PTSD during follow-up. Receipt of prescription stimulants were significantly associated with incident PTSD, hazard ratio = 5.09, 95% confidence interval [3.05, 8.50], after adjusting for sociodemographic factors, military characteristics, attention-deficit/hyperactivity disorder, baseline mental and physical health status, deployment experiences, and physical/sexual trauma. Findings suggested that prescription stimulants are associated with incident PTSD among military personnel; these data may inform the underlying pathogenesis of and preventive strategies for PTSD.

Hearing loss associated with US military combat deployment.

The objective of this study was to define the risk of hearing loss among US military members in relation to their deployment experiences. Data were drawn from the Millennium Cohort Study. Self-reported data and objective military service data were used to assess exposures and outcomes. Among all 48,540 participants, 7.5% self-reported new-onset hearing loss. Self-reported hearing loss showed moderate to substantial agreement (k = 0.57-0.69) with objective audiometric measures. New-onset hearing loss was associated with combat deployment (adjusted odds ratio [AOR] = 1.63, 95% confidence interval [CI] = 1.49-1.77), as well as male sex and older age. Among deployers, new-onset hearing loss was also associated with proximity to improvised explosive devices (AOR = 2.10, 95% CI = 1.62-2.73) and with experiencing a combat-related head injury (AOR = 6.88, 95% CI = 3.77-12.54). These findings have implications for health care and disability planning, as well as for prevention programs.

The impact of prior deployment experience on civilian employment after military service.

OBJECTIVE: To determine if deployment to recent military operations or other health, demographic, or military-related characteristics were associated with employment after military service. METHODS: Former US active duty military service members participating in the Millennium Cohort Study, a population-based sample of US military personnel that began in July of 2001, were prospectively followed from the time of baseline health reporting to self-reported employment status after military separation. RESULTS: Of the 9099 separated personnel meeting inclusion criteria, 17% reported unemployment after military service. In multivariable modelling, prior deployment experiences, with or without reported combat, and post-traumatic stress disorder (PTSD) were not significantly associated with employment status postservice. Among those who routinely retired from service with a pension, positive screens for depression (OR, 1.67; 95% CI, 1.05 to 2.63) and panic/anxiety (OR, 1.63; 95% CI, 1.10 to 2.43) were significantly associated with subsequent unemployment. Poor physical health, female sex, black race, lower education and disabling illnesses/injuries were also predictive of postservice unemployment. CONCLUSIONS: After stratifying for reason for military separation, mental disorders like depression or panic/anxiety and poor physical health may have greater impact than prior deployment experiences or PTSD on the ability to find or maintain employment postservice. These findings may guide support for veterans most in need of job placement services after military service.

Prospective evaluation of mental health and deployment experience among women in the US military.

Previous research has shown that military women often experience potentially severe health outcomes following deployment. Data from the Millennium Cohort Study, a 21-year longitudinal study examining the health effects of military service, were used to examine this issue. In longitudinal analyses (2001-2008) carried out among US military women (n = 17,481), the authors examined positive screens for depression, anxiety, panic, and posttraumatic stress disorder in relation to deployment in support of the operations in Iraq and Afghanistan, while adjusting for relevant baseline and time-varying covariates. Women who were deployed and reported combat-related exposures had greater odds than nondeployed women of reporting symptoms of a mental health condition (odds ratio = 1.91, 95% confidence interval: 1.65, 2.20), after adjustment for demographic, military, and behavioral covariates. In addition, higher stress, problem drinking, and a history of mental illness were significantly associated with increased risk of later mental health conditions. In contrast, women in the Reserves or National Guard and those with higher education were at decreased risk of mental health conditions (all P 's < 0.01). As the roles and responsibilities of women in the military expand and deployments continue, designing better prevention and recovery strategies specifically for women are critical for overall force health protection and readiness.

A comparison of mental health outcomes in persons entering U.S. military service before and after September 11, 2001.

It has been hypothesized that those who entered military service in the pre-September 11, 2001 era might have expectations incongruent with their subsequent experiences, increasing the risk for posttraumatic stress disorder (PTSD) or other mental disorders. A subset of Millennium Cohort Study participants who joined the military during 1995-1999 was selected and compared with a subset of members who joined the military in 2002 or later. Outcomes included new-onset symptoms of PTSD, depression, panic/anxiety, and alcohol-related problems. Multivariable methods adjusted for differences in demographic and military characteristics. More than 11,000 cohort members were included in the analyses. Those who entered service in the pre-September 11 era had lower odds of new-onset PTSD symptoms (odds ratio [OR] 0.74, 95% CI [0.59, 0.93]) compared with the post-September 11 cohort. There were no statistically significant differences in rates of new-onset symptoms of depression, panic/anxiety, or alcohol-related problems between the groups. The cohort who entered military service in the pre-September 11 era did not experience higher rates of new-onset mental health challenges compared with the cohort who entered service after September 11, 2001. Findings support the concept that the experience of war, and resulting psychological morbidity, is not a function of incongruent expectations.

Posttraumatic stress disorder and depression among U.S. military health care professionals deployed in support of operations in Iraq and Afghanistan.

Limited prospective studies exist that evaluate the mental health status of military health care professionals who have deployed. This study used prospective data from the Millennium Cohort Study with longitudinal analysis techniques to examine whether health care professionals deployed in support of the operations in Iraq and Afghanistan were more likely to screen positive for new-onset posttraumatic stress disorder (PTSD) or depression after deployment than individuals from other occupations. Of 65,108 subjects included, 9,371 (14.4%) reported working as health care professionals. The rates of new positive screens for PTSD or depression were similar for those in health care occupations (4.7% and 4.3%) compared with those in other occupations (4.6% and 3.9%) for the first and second follow-up, respectively. Among military personnel deployed with combat experience, health care professionals did not have increased odds for new-onset PTSD or depression over time. Among deployed health care professionals, combat experience significantly increased the odds: adjusted odds ratio = 2.01; 95% confidence interval [1.06, 3.83] for new-onset PTSD or depression. These results suggest that combat experience, not features specific to being a health care professional, was the key exposure explaining the development of these outcomes.

Health outcomes among infants born to women deployed to United States military operations during pregnancy.

BACKGROUND: Military professionals who deploy to combat operations may encounter hazards that could adversely affect reproductive health. Pregnant women are generally exempt from deployment to military operations; however, exposures to such environments may inadvertently occur. We investigated whether maternal deployment during pregnancy was associated with adverse health outcomes in infants. METHODS: The United States Department of Defense Birth and Infant Health Registry identified infants born to military service women between 2002 and 2005, and defined their health outcomes at birth and in the first year of life. Multivariable modeling was applied to investigate preterm birth and birth defects among infants, based on maternal deployment experience during pregnancy. RESULTS: Among 63,056 infants born to military women from 2002 to 2005, 22,596 were born to women with deployment experience in support of the current military operations before, during, or after their pregnancy. These included 2941 infants born to women who appeared to have been deployed some time during their first trimester of pregnancy. Compared to infants born to women who deployed at other times, or never deployed, exposed infants were not more likely to be born preterm, diagnosed with a major birth defect, or diagnosed with a malignancy. CONCLUSIONS: In this exploratory analysis, infants born to women who inadvertently deployed to military operations during their pregnancy were not at increased risk of adverse birth or infant health outcomes. Future analyses should examine outcomes related to specific maternal exposures during deployment, and outcomes among the growing number of infants conceived after deployment.

Application of latent semantic analysis for open-ended responses in a large, epidemiologic study.

BACKGROUND: The Millennium Cohort Study is a longitudinal cohort study designed in the late 1990s to evaluate how military service may affect long-term health. The purpose of this investigation was to examine characteristics of Millennium Cohort Study participants who responded to the open-ended question, and to identify and investigate the most commonly reported areas of concern. METHODS: Participants who responded during the 2001-2003 and 2004-2006 questionnaire cycles were included in this study (n = 108,129). To perform these analyses, Latent Semantic Analysis (LSA) was applied to a broad open-ended question asking the participant if there were any additional health concerns. Multivariable logistic regression was performed to examine the adjusted odds of responding to the open-text field, and cluster analysis was executed to understand the major areas of concern for participants providing open-ended responses. RESULTS: Participants who provided information in the open-ended text field (n = 27,916), had significantly lower self-reported general health compared with those who did not provide information in the open-ended text field. The bulk of responses concerned a finite number of topics, most notably illness/injury, exposure, and exercise. CONCLUSION: These findings suggest generalized topic areas, as well as identify subgroups who are more likely to provide additional information in their response that may add insight into future epidemiologic and military research.

Health impact of US military service in a large population-based military cohort: findings of the Millennium Cohort Study, 2001-2008.

BACKGROUND: Combat-intense, lengthy, and multiple deployments in Iraq and Afghanistan have characterized the new millennium. The US military's all-volunteer force has never been better trained and technologically equipped to engage enemy combatants in multiple theaters of operations. Nonetheless, concerns over potential lasting effects of deployment on long-term health continue to mount and are yet to be elucidated. This report outlines how findings from the first 7 years of the Millennium Cohort Study have helped to address health concerns related to military service including deployments. METHODS: The Millennium Cohort Study was designed in the late 1990s to address veteran and public concerns for the first time using prospectively collected health and behavioral data. RESULTS: Over 150,000 active-duty, reserve, and National Guard personnel from all service branches have enrolled, and more than 70% of the first 2 enrollment panels submitted at least 1 follow-up survey. Approximately half of the Cohort has deployed in support of operations in Iraq and Afghanistan. CONCLUSION: The Millennium Cohort Study is providing prospective data that will guide public health policymakers for years to come by exploring associations between military exposures and important health outcomes. Strategic studies aim to identify, reduce, and prevent adverse health outcomes that may be associated with military service, including those related to deployment.

Racial differences in prostate cancer risk remain among US servicemen with equal access to care.

BACKGROUND: Prostate cancer is the most common cancer among US men, however, the etiology remains unclear. Yet, one consistency is that black non-Hispanic men are at increased risk for prostate cancer compared to white, non-Hispanic men. The goal of this study was to assess relations between demographic and other potential prostate cancer risk factors in the context of the US military healthcare system, which provides equal access to all US servicemen. METHODS: Military healthcare and demographic data were used to describe risk factors for prostate cancer in the US military from September 1993 to September 2003. Cox's proportional hazards regression was employed to model the time to prostate cancer hospitalization. RESULTS: Four hundred eight first prostate cancer hospitalizations were identified among 2,761,559 servicemen. The adjusted rate per 100,000 persons rose from 1.41 to 3.62 for white non-Hispanic men and 1.43 to 6.08 for black non-Hispanic men by the end of the study. The increasing incidence over time for combined race/ethnic groups was similar to trends reported in the Surveillance, Epidemiology, and End Results Program for the US civilian population. No association was observed between occupation and prostate cancer hospitalization. However, black non-Hispanic men were at increased risk compared with white non-Hispanic men (hazard ratio = 2.72, 95% confidence interval: 2.12, 3.49). CONCLUSIONS: No association was observed between occupation and prostate cancer hospitalization. In this relatively young cohort, black non-Hispanic race/ethnicity was found to be predictive of prostate cancer, and this association existed regardless of access to care and socioeconomic status.

A prospective study of depression following combat deployment in support of the wars in Iraq and Afghanistan.

OBJECTIVE: We investigated relations between deployment and new-onset depression among US service members recently deployed to the wars in Iraq and Afghanistan. METHODS: We included 40 219 Millennium Cohort Study participants who completed baseline and follow-up questionnaires and met inclusion criteria. Participants were identified with depression if they met the Primary Care Evaluation of Mental Disorders Patient Health Questionnaire criteria for depression at follow-up, but not at baseline. RESULTS: Deployed men and women with combat exposures had the highest onset of depression, followed by those not deployed and those deployed without combat exposures. Combat-deployed men and women were at increased risk for new-onset depression compared with nondeployed men and women (men: adjusted odds ratio [AOR]=1.32; 95% confidence interval [CI]=1.13, 1.54; women: AOR=2.13; 95% CI=1.70, 2.65). Conversely, deployment without combat exposures led to decreased risk for new-onset depression compared with those who did not deploy (men: AOR=0.66; 95% CI=0.53, 0.83; women: AOR=0.65; 95% CI=0.47, 0.89). CONCLUSIONS: Deployment with combat exposures is a risk factor for new-onset depression among US service members. Post-deployment screening may be beneficial for US service members exposed to combat.

Disordered eating and weight changes after deployment: longitudinal assessment of a large US military cohort.

The effect of military deployments to combat environments on disordered eating and weight changes is unknown. Using longitudinal data from Millennium Cohort Study participants who completed baseline (2001-2003) and follow-up (2004-2006) questionnaires (n=48,378), the authors investigated new-onset disordered eating and weight changes in a large military cohort. Multivariable logistic regression was used to compare these outcomes among those who deployed and reported combat exposures, those who deployed but did not report combat exposures, and those who did not deploy in support of the wars in Iraq and Afghanistan. Deployment was not significantly associated with new-onset disordered eating in women or men, after adjustment for baseline demographic, military, and behavioral characteristics. However, in subgroup comparison analyses of deployers, deployed women reporting combat exposures were 1.78 times more likely to report new-onset disordered eating (95% confidence interval: 1.02, 3.11) and 2.35 times more likely to lose 10% or more of their body weight compared with women who deployed but did not report combat exposures (95% confidence interval: 1.17, 4.70). Despite no significant overall association between deployment and disordered eating and weight changes, deployed women reporting combat exposures represent a subgroup at higher risk for developing eating problems and weight loss.

PTSD prevalence, associated exposures, and functional health outcomes in a large, population-based military cohort.

OBJECTIVES: Posttraumatic stress disorder (PTSD) results from experiencing or witnessing traumatic, life-threatening events including combat-related experiences. The purpose of this study was to investigate the prevalence of PTSD symptoms and diagnosis, self-reported exposures, and functional health in a large cross-section of the U.S. military. METHODS: This study used baseline Millennium Cohort data (July 2001 to June 2003) of 75,156 U.S. military members to assess the population-based prevalence of PTSD symptoms, self-reported exposures, and functional health as measured by the Medical Outcomes Study Short Form 36-Item Health Survey for Veterans (SF-36V). RESULTS: PTSD diagnosis without current symptoms was reported by 953 respondents (1.2%, weighted), 1,490 respondents (2.1%, weighted) reported no diagnosis but reported PTSD symptoms, and 287 respondents (0.4%, weighted) reported diagnosis and current symptoms. Self-reported exposure to chemical or biological warfare agents, protective countermeasures, or hearing alarms were associated with PTSD symptoms independent of other combat-like exposures. Physical health was similar among those with PTSD diagnosis and current PTSD symptoms. However, compared with the overall cohort, lower mental health summary means for those reporting current PTSD symptoms (mean = 27.8), current symptoms and diagnosis (mean = 24.6), and diagnosis without current symptoms (mean = 47.5) were found. CONCLUSIONS: Results suggest a 2.0% prevalence of PTSD symptoms without diagnosis and that self-reported threatening exposures were significantly associated with PTSD symptoms. Mental and physical health scores of those with current PTSD symptoms appear diminished, but suggest a return to cohort levels with resolution of PTSD symptoms.

Does acute maternal stress in pregnancy affect infant health outcomes? Examination of a large cohort of infants born after the terrorist attacks of September 11, 2001.

BACKGROUND: Infants in utero during the terrorist attacks of September 11, 2001 may have been negatively affected by maternal stress. Studies to date have produced contradictory results. METHODS: Data for this retrospective cohort study were obtained from the Department of Defense Birth and Infant Health Registry and included up to 164,743 infants born to active-duty military families. Infants were considered exposed if they were in utero on September 11, 2001, while the referent group included infants gestating in the same period in the preceding and following year (2000 and 2002). We investigated the association of this acute stress during pregnancy with the infant health outcomes of male:female sex ratio, birth defects, preterm birth, and growth deficiencies in utero and in infancy. RESULTS: No difference in sex ratio was observed between infants in utero in the first trimester of pregnancy on September 11, 2001 and infants in the referent population. Examination of the relationship between first-trimester exposure and birth defects also revealed no significant associations. In adjusted multivariable models, neither preterm birth nor growth deficiencies were significantly associated with the maternal exposure to the stress of September 11 during pregnancy. CONCLUSION: The findings from this large population-based study suggest that women who were pregnant during the terrorist attacks of September 11, 2001 had no increased risk of adverse infant health outcomes.

Pregnancy, birth, and infant health outcomes from the National Smallpox Vaccine in Pregnancy Registry, 2003-2006.

When the United States implemented civilian and military smallpox vaccination programs in 2003, the National Smallpox Vaccine in Pregnancy Registry was established to better evaluate outcomes after the inadvertent vaccination of pregnant women. Women were referred to the registry by vaccine administrators, health care providers, or state health departments or through self-referral. Registry professionals actively follow up with all enrolled women and collect data on pregnancy, birth, and infant health outcomes. As of September 2006, pregnancy outcome data were available from 376 women. Most (77%) were vaccinated near the time of conception, before results of a standard pregnancy test would have been positive. To date, outcome evaluations have not revealed higher-than-expected rates of pregnancy loss (11.9%), preterm birth (10.7%), or birth defects (2.8%), compared with those in healthy referent populations. No cases of fetal vaccinia have been identified. The Smallpox Vaccine in Pregnancy Registry continues to actively enroll women and follow infant and early-childhood health outcomes.

Birth defects among infants born to women who received anthrax vaccine in pregnancy.

In response to bioterrorism threats, anthrax vaccine has been used by the US military and considered for civilian use. Concerns exist about the potential for adverse reproductive health effects among vaccine recipients. This retrospective cohort evaluated birth defects, in relation to maternal anthrax vaccination, among all infants born to US military service women between 1998 and 2004. Department of Defense databases defined maternal vaccination and infant diagnoses; multivariable regression models described potential associations between anthrax vaccination and birth defects in liveborn infants. Among 115,169 infants born to military women during this period, 37,140 were born to women ever vaccinated against anthrax, and 3,465 were born to women vaccinated in the first trimester of pregnancy. Birth defects were slightly more common in first trimester-exposed infants (odds ratio = 1.18, 95% confidence interval: 0.997, 1.41) when compared with infants of women vaccinated outside of the first trimester, but this association was statistically significant only when alternative referent groups were used. Although the small observed association may be unlikely to represent a causal relation between vaccination in early pregnancy and birth defects, this information should be considered when making decisions about administering anthrax vaccine to pregnant women.

Evaluating the epidemiology of inflicted traumatic brain injury in infants of U.S. military families.

BACKGROUND: Evaluating the incidence of inflicted traumatic brain injuries (inflicted TBI) in young children, and encompassing shaken baby syndrome (SBS) and related injuries, is an epidemiologic challenge. Data available regarding military families in the U.S. may complement other national surveillance efforts. METHODS: A protocol was developed to assess the epidemiology of inflicted TBI among infants of U.S. military families, integrating data from the Department of Defense Birth and Infant Health Registry, healthcare utilization databases, child abuse reporting systems, and military personnel databases. The in-progress protocol, and its inherent strengths and limitations, are described here. DISCUSSION: The primary strengths of data from U.S. military families are related to the full characterization of the denominator, such that analyses are person-time and population based. Unique data are available to describe the full population of military parents, including occupational, geographic, and socioeconomic factors, as well as deployment-related potential stressors. The limitations of military data are similar to many other child abuse surveillance systems in that cases are underreported and not fully characterized. Linking abuse reports and medical utilization data to population data, however, will allow unique analyses of "probable" and "possible" cases of inflicted TBI in infants of military families. CONCLUSIONS: Data from the U.S. military, when appropriately linked and analyzed, provide opportunities to evaluate important risk factors for inflicted TBI in infants. Although epidemiologic challenges may make incidence rates using military data noncomparable to rates using other data sources, multivariate analyses can evaluate critical and unique risk factors, as well as the effectiveness of prevention initiatives.

Evaluation of preterm births and birth defects in liveborn infants of US military women who received smallpox vaccine.

BACKGROUND: Women serving in the US military have some unique occupational exposures, including exposure to vaccinations that are rarely required in civilian professions. When vaccinations are inadvertently given during pregnancy, such exposures raise special concerns. These analyses address health outcomes, particularly preterm births and birth defects, among infants who appear to have been exposed to maternal smallpox vaccination in pregnancy. METHODS: This retrospective cohort study included 31,420 infants born to active-duty military women during 2003-2004. We used Department of Defense databases to define maternal vaccination and infant health outcomes. Multivariable regression models were developed to describe associations between maternal smallpox vaccination and preterm births and birth defects in liveborn infants. RESULTS: There were 7,735 infants identified as born to women ever vaccinated against smallpox, and 672 infants born to women vaccinated in the first trimester of pregnancy. In multivariable modeling, maternal smallpox vaccination in pregnancy was not associated with preterm or extreme preterm delivery. Maternal smallpox vaccination in the first trimester of pregnancy was not significantly associated with overall birth defects (OR 1.40; 95% CI: 0.94, 2.07), or any of seven specific defects individually modeled. CONCLUSIONS: Results may be reassuring that smallpox vaccine, when inadvertently administered to pregnant women, is not associated with preterm delivery or birth defects in liveborn infants.

Challenges of self-reported medical conditions and electronic medical records among members of a large military cohort.

BACKGROUND: Self-reported medical history data are frequently used in epidemiological studies. Self-reported diagnoses may differ from medical record diagnoses due to poor patient-clinician communication, self-diagnosis in the absence of a satisfactory explanation for symptoms, or the "health literacy" of the patient. METHODS: The US Department of Defense military health system offers a unique opportunity to evaluate electronic medical records with near complete ascertainment while on active duty. This study compared 38 self-reported medical conditions to electronic medical record data in a large population-based US military cohort. The objective of this study was to better understand challenges and strengths in self-reporting of medical conditions. RESULTS: Using positive and negative agreement statistics for less-prevalent conditions, near-perfect negative agreement and moderate positive agreement were found for the 38 diagnoses. CONCLUSION: This report highlights the challenges of using self-reported medical data and electronic medical records data, but illustrates that agreement between the two data sources increases with increased surveillance period of medical records. Self-reported medical data may be sufficient for ruling out history of a particular condition whereas prevalence studies may be best served by using an objective measure of medical conditions found in electronic healthcare records. Defining medical conditions from multiple sources in large, long-term prospective cohorts will reinforce the value of the study, particularly during the initial years when prevalence for many conditions may still be low.

Haemangiomas and associated congenital malformations in a large population-based sample of infants.

Haemangiomas are common, benign, vascular tumours, observed in 4-12% of infants during the first year of life. Most cases progress without complication, yet a small proportion experience life-threatening complications. Concomitant congenital malformations have been reported in a small but significant proportion of haemangioma patients. This study aimed to describe haemangioma cases and to identify patterns of congenital malformations associated with these diagnoses in a large population. Diagnoses of haemangiomas and 21 congenital malformations were extracted from electronic medical records of 467 295 singleton infants born to US military families from 1998 to 2003. Cluster analysis was used to group cases according to these diagnoses. Multivariable logistic regression was used to further explore the associations of the 21 congenital malformations with the diagnosis of haemangioma and to assess the adjusted relationships between a number of characteristics of interest and diagnosis of haemangioma. Clusters found to be associated with haemangioma were characterised by anomalies of the cervix, vagina, and external female genitalia, anophthalmia or microphthalmia, hydrocephalus without spina bifida, and reduction deformities of the brain. Logistic regression identified three congenital malformations significantly associated with haemangioma diagnosis: spina bifida without anencephalus, hydrocephalus without spina bifida, and anomalies of the cervix, vagina and external female genitalia. Characteristics significantly associated with haemangioma included female gender, preterm birth, white non-Hispanic race/ethnicity and increasing maternal age. This exploratory study identified a number of important associations between haemangiomas and congenital malformations that may provide insight into the pathogenesis of these disorders and have possible implications for clinical care.