The US Department of Defense Millennium Cohort Study: Career Span and Beyond Longitudinal Follow-Up

Sleep health among US Navy afloat versus ashore personnel in the Millennium Cohort Study

Despite emerging public concern regarding the sleep health of military personnel over the past two decades, there remains a dearth of research examining sleep health among naval personnel assigned to sea duty. This study examined sleep metrics (e.g. fatigue, short sleep duration) and mental (e.g. posttraumatic stress disorder, depression) and physical health (e.g. type 2 diabetes, bodily pain) outcomes among naval personnel with recent sea duty (i.e. afloat) compared with naval personnel with recent shore duty (i.e. ashore). Prevalence ratios and mean differences for all outcomes were estimated and adjusted for demographic and military variables, and subsequently stratified by obesity. Sleep metrics were similar between afloat and ashore sailors except for short sleep duration, while sailors with recent shore duty had poorer physical health compared with those with recent sea duty. Stratified analyses suggested naval personnel with obesity had a higher proportion of nearly all adverse sleep-related health outcomes than those without obesity. Among participants without obesity, afloat personnel were more likely to report very short sleep (≤ 5 hours) and fewer hours of average nightly sleep, but were less likely to report physical health outcomes compared with ashore personnel. These findings suggest potential differences in sleep metrics and sleep-related health outcomes between afloat and ashore naval personnel. Additional research examining sleep outcomes using more objective measures is required to further investigate these findings, which may inform strategies to foster consolidated sleep despite environmental and occupational challenges in order to maintain high-performing naval personnel.

Prospective comparison of risk factors for firearm suicide and non-firearm suicide in a large population-based cohort of current and former US service members: findings from the Millennium Cohort Study

Background

Suicide is a leading cause of death among service members and veterans. Among suicide methods, firearms are the most lethal and commonly used method among military populations. Limited research has compared risk factors for the various suicide methods. This study evaluated and compared risk factors for firearm versus non-firearm suicides using data from the Millennium Cohort Study, a large longitudinal military cohort.

Methods

Using a competing risk approach, we identified factors associated with each suicide method. Risk factors included demographics, mental health diagnoses, mental health symptoms, military-specific characteristics, health behaviors, and psychosocial factors. Cause of death was assessed from July 1, 2001, through December 31, 2018.

Findings

Among 201,565 eligible participants with a mean [SD] age of 29.0 [58.1] years, there were 139,789 (69.3%) male, 61,776 (30.7%) female, 15,927 (7.9%) Hispanic, 24,667 (12.3%) non-Hispanic Black, 14,138 (7.0%) Asian, Pacific Islander, American Indian or Multiracial, and 146,736 (72.8%) non-Hispanic White participants. During the study period, 330 died by firearm suicide and 168 died by non-firearm suicide. Overall, effect estimates for risk factors were similar across both methods of suicide. After adjustment, men (HR: 3.69, 95% CI: 2.59, 5.24) and those who screened positive for depression (HR: 1.97, 95% CI: 1.36, 2.87) had an elevated risk for firearm suicide. In contrast, those who self-reported a history of bipolar diagnosis (HR: 3.40, 95% CI: 1.76, 6.55) had significantly increased risk for non-firearm suicide.

Interpretation

Findings suggest that prevention and intervention strategies overall may not need to be differentiated by specific demographic, military, or health factors. Targeted interventions that consider sex and mental health screens might have relative utility in preventing firearm related suicide risk compared with non-firearm suicide.

Funding

Military Operational Medicine Research Program, Defense Health Program, and Department of Veterans Affairs.

Three-Item Dimensions of Anger Reactions Scale

Importance

Problematic anger is prevalent and associated with adjustment difficulties in military populations. To facilitate measurement of problematic anger, a very brief valid measure is needed.

Objective

To reduce the Dimensions of Anger Reactions 5-item (DAR-5) scale to a very brief measure.

Design, Setting, and Participants

This cross-sectional study used survey data collected between 2014 and 2016 in the Australian Transition and Well-Being Research Programme and US Millennium Cohort Study. Participants were service members who were actively serving or had transitioned out of the military (separated). Statistical analyses were performed from September 2021 to June 2023.

Main Outcomes and Measures

The DAR-5 was reduced to the 3 experiential items: frequency, intensity, and duration (the DAR-3). Psychometrics for the DAR-3 and DAR-5 were compared in terms of standardized Cronbach α, positive screening result, mean, and SD. Analyses were stratified by Australian and US military service status cohorts (active duty and separated).

Results

A total of 71 010 participants were included from Australia and the US. Of 10 900 Australian participants (8145 active duty participants [74.7%]; 2755 separated participants [25.3%]), 5893 (55.2%) were aged 40 years or older and 8774 (80.5%) were male; of 60 110 US participants (24 706 active duty participants [41.1%]; 35 404 separated participants [58.9%]), 28 804 (47.9%) were aged 30 to 39 years and 43 475 (72.3%) were male. The DAR-3 demonstrated good internal consistency in the active duty (Australia: mean [SD] score, 4.97 [2.5]; α = 0.90; US: mean [SD] score, 5.04 [2.6]; α = 0.87) and separated (Australia: mean [SD] score, 6.53 [3.4]; α = 0.92; US: mean [SD] score, 6.05 [3.2]; α = 0.91) samples. The cutoff score of 8 or greater on the DAR-3 had optimal sensitivity and specificity across all samples. DAR-3 and DAR-5 were associated with posttraumatic stress disorder (PTSD), depression, aggression, and relationship conflict. While the scales did not significantly differ in their associations with PTSD, depression, and relationship conflict, the magnitude of association for aggression was significantly lower in US samples using the DAR-3 (eg, US active duty sample: DAR-5 OR, 9.96; 95% CI, 9.01-11.00; DAR-3 OR, 8.36; 95% CI, 7.58-9.22).

Conclusions and Relevance

In this cross-sectional study of a very brief measure of anger, each item contributed to the overall strength of the measure without losing psychometric strength compared with the DAR-5. The consistency of these findings across military and veteran samples in Australian and US populations demonstrated the psychometric robustness of the DAR-3.

Identifying at-risk marines: A person-centered approach to adverse childhood experiences, mental health, and social support

BACKGROUND

Previous research indicates an association between adverse childhood experiences (ACES) and health outcomes; however, most of these studies rely on variable-centered techniques. This study implemented a person-centered approach to provide a more nuanced understanding of these relations.

METHODS

The sample consisted of 3611 male Marines who completed two surveys, one prior to service and another during or after service. A series of latent class analyses were conducted to identify homogenous subgroups, using ACE categories as indicators. Hierarchical regressions were conducted to examine the relationships between classes, deployment experiences, depression and PTSD, and social support problems.

RESULTS

Five classes were identified: Low Adversity (48.8 %), Low Adversity - Parental Separation (PS; 33.1 %), Elevated Adversity (7.0 %), Moderate Adversity - Violence/Safety (5.7 %), and Moderate Adversity - Parental Loss (PL; 5.4 %). Several classes were associated with outcomes; in reference to Low Adversity, Moderate Adversity - PL was associated with depression and PTSD, Elevated Adversity was associated with PTSD and social support problems, and Low Adversity - PS was associated with social support problems. Experiencing moderate to high combat appeared to modify the associations between Moderate Adversity - PL and depression and PTSD.

LIMITATIONS

Study sample was limited to U.S. Marines; ACEs indicators were limited to specific categories, not allowing for a full range of potential childhood traumatic experiences.

CONCLUSIONS

Findings suggest a nuanced connection between ACEs and mental health; using specific patterns of ACEs, particularly multifaceted indicators of adversity that are inclusive of parental absence may have more utility than the sheer number of ACEs as an indicator for those who may at a heightened risk for mental health concerns.

Contribution of post-trauma insomnia to depression and posttraumatic stress disorder in women service members: findings from the Millennium Cohort Study

STUDY OBJECTIVES

We examined whether women service members and veterans who reported recent combat and/or sexual trauma experiences had a greater risk of insomnia compared with women who did not report these recent experiences, and whether insomnia would be associated with a greater risk of mental health outcomes.

METHODS

We analyzed two waves of survey data (2011-2013, Time 1 [T1] and 2014-2016, Time 2 [T2]) from 26 443 current and former women service members from the Millennium Cohort Study. We assessed recent traumas in the past 3 years, and probable insomnia at T1 and probable post-traumatic stress disorder (PTSD) and depression at T2. A longitudinal mediation model was used to quantify separate indirect effects of recent traumas on mental health outcomes through probable insomnia.

RESULTS

Women who had experienced recent sexual assault (odds ratio [OR] = 1.68; 95% CI = 1.24-2.10), sexual harassment (OR = 1.22; 95% CI = 1.05-1.41), and combat (OR = 1.34; 95% CI = 1.20-1.49) at T1 had a greater risk of probable insomnia at T1 compared with women who had not recently experienced these events. Probable insomnia at T1, in turn, was associated with probable depression (OR = 2.66; 95% CI = 2.31-3.06) and PTSD (OR = 2.57; 95% CI = 2.27-2.90) at T2. Recent combat experience did not moderate the associations of recent sexual trauma with insomnia or mental health outcomes.

CONCLUSIONS

Insomnia contributes to the risk of subsequent mental health conditions following trauma. The diagnosis and treatment of post-trauma insomnia should be prioritized to mitigate the development of posttraumatic mental health conditions.

Health Disparities Among Lesbian, Gay, and Bisexual Service Members and Veterans

INTRODUCTION

This study investigated whether health disparities exist among lesbian, gay, and bisexual individuals serving in the U.S. military by examining the associations of sexual orientation with mental, physical, and behavioral health among a population-based sample of service members and veterans.

METHODS

Sexual orientation and health outcomes were self-reported on the 2016 Millennium Cohort Study follow-up questionnaire (N=96,930). Health outcomes were assessed across 3 domains: mental health (post-traumatic stress disorder, depression, anxiety, binge eating, problematic anger), physical health (multiple somatic symptoms, physical functioning, BMI), and behavioral health (smoking, problem and risky drinking, insomnia). Adjusted logistic regression models conducted between 2019 and 2022 estimated the associations between sexual orientation and each health outcome.

RESULTS

Lesbian, gay, and bisexual individuals (3.6% of the sample) were more likely to screen positive for post-traumatic stress disorder, depression, anxiety, binge eating, problematic anger, multiple somatic symptoms, and insomnia than heterosexual individuals. Gay/lesbian and bisexual women reported more adverse health outcomes (overweight and obesity, smoking, problem/risky drinking) than heterosexual women. Gay and bisexual men reported some adverse health outcomes (e.g., smoking and problem drinking) but better physical health (e.g., less overweight/obesity) than heterosexual men.

CONCLUSIONS

Lesbian, gay, and bisexual service members reported poorer mental, physical, and behavioral health than heterosexual peers, most notably among gay/lesbian women and bisexual individuals. Findings suggest that lesbian, gay, and bisexual service members experience health disparities, despite many having equal eligibility for health care, highlighting the need for improved equity initiatives that promote cultural responsiveness, acceptance, and approaches to support the healthcare needs of lesbian, gay, and bisexual military members.

The relative impact of injury and deployment on mental and physical quality of life among military service members

US service members injured in the recent conflicts in Iraq and Afghanistan were more likely to survive than those in previous conflicts because of advances in medicine and protective gear. However, there is limited research examining the long-term impact of injuries while deployed on physical and mental quality of life (QOL) among service members. We used data from two time-points with an average follow-up period of 4.27 years (SD = 2.13; n = 118,054) to prospectively examine the association between deployment and injury status with QOL. Data were derived from the Millennium Cohort Study surveys (2001 to 2016) and linked with the Department of Defense Trauma Registry (DoD-TR) among a cohort of US service members from all branches and components. The primary predictor (a combination of deployment and injury status) was comprised of the following four categories: 1) not deployed, 2) deployed and not injured, 3) deployed and non-battle injured, and 4) deployed and battle injured. Demographic, military, psychological and behavioral health, and life stress factors were adjusted for in multivariable models. Outcomes of interest were physical and mental QOL from the Short-Form Health Survey for Veterans (VR-36) measured at ~4 year follow-up. Between group comparisons indicated that those deployed and battle-injured had the greatest decline in both mental (-3.82) and physical (-10.13) QOL scores over time (p < .05). While deployment and injury status were associated with poorer mental and physical QOL in adjusted models; only the association between deployment and injury status with physical QOL was clinically meaningful (more than 2.5). In adjusted models, Time 1 mental and physical QOL explained most of the variance (23–25%) in Time 2 mental and physical health QOL as compared to other covariates (e.g., injury and deployment, and other sociodemographic factors increased variance by ~5%). Time 1 QOL was the most significant predictor of later QOL, but those injured while deployed experienced significant and meaningful decrements to long-term physical QOL. This suggests that prevention and rehabilitation interventions should focus on improving physical health among injured service members to avoid long-term adverse effects.

Association of Problematic Anger With Long-term Adjustment Following the Military-to-Civilian Transition

Importance

Few studies have examined the role of problematic anger in long-term adjustment of service members transitioning out of the military.

Objective

To determine the prevalence of problematic anger during the military-to-civilian transition period and the association of problematic anger with adjustment to civilian life.

Design, Setting, and Participants

This cohort study used 2 waves of survey data administered approximately 5 years apart (time 1 [T1; September 26, 2014, to August 25, 2016] and time 2 [T2; October 23, 2019, to August 31, 2021]) from the Millennium Cohort Study, a population-based military study. Participants were US active-duty service members within 24 months of separating from military service at T1. Statistical analysis was performed from September 2021 to May 2022.

Exposures

Problematic anger was operationalized as scoring at least 12 points on the 5-item Dimensions of Anger Reactions scale at T1.

Main Outcomes and Measures

Behavioral and functional health (depression, posttraumatic stress disorder, problem drinking, functional limitations), relationship health (relationship quality, coping with parental demands, social support), and economic health (major financial problems, financial insecurity, homelessness, employment status) were assessed at T2. Covariates, assessed at T1, included demographics, military characteristics, mental health, problem drinking, and physical health.

Results

Of the 3448 participants, 2625 (76.1%) were male, 217 (6.3%) were Hispanic, 293 (8.5%) were non-Hispanic Black, and 2690 (78.0%) were non-Hispanic White; the mean (SD) age was 40.1 (8.5) years; 826 (24.0%) met criteria for problematic anger. Prevalence of problematic anger was 15.9% (95% CI, 12.2%-19.7%) 24 months prior to military separation and 31.2% (95% CI, 26.2%-36.2%) 24 months following separation. After adjusting for covariates, problematic anger was associated with greater likelihood of behavioral and functional health outcomes (eg, posttraumatic stress disorder: adjusted odds ratio, 1.55, 95% CI, 1.23-1.96), relationship health difficulties (eg, low social support: aOR, 1.66; 95% CI, 1.23-2.24), and economic difficulties (eg, substantial financial insecurity: aOR, 1.64; 95% CI, 1.13-2.39) at T2.

Conclusions and Relevance

This cohort study found an association between prevalence of problematic anger during the military-to-civilian transition and problematic anger with subsequent adjustment difficulties among US service members. These findings suggest the need to equip service members proactively with skills to identify and manage anger as a way to support them before and during this period of transition.

Combat exposure and behavioral health in U.S. Army Special Forces

Although combat has been found to be associated with adverse health outcomes, little is known about the impact of specific combat exposures, particularly among specialized personnel. This study examined the association of different types of combat exposures with behavioral health outcomes, and whether these associations differed by Army occupational specialization: General Purpose Forces infantrymen (n = 5,361), Ranger Qualified infantrymen (n = 308), and Special Forces personnel (n = 593). Multivariable regression models estimated the association of combat severity, type of combat event (fighting, killing, threat to oneself, death/injury of others), and type of killing with mental health disorders, trouble sleeping, and problem drinking. Combat severity, each type of combat event, and killing noncombatants were associated with adverse health outcomes after adjusting for covariates and other combat exposures. Except for trouble sleeping, these associations did not differ by occupational specialization, though the prevalence and odds of outcomes were generally lower for Special Forces personnel.

Factors Associated with Human Papillomavirus Vaccine Initiation and Compliance Among U.S. Military Service Members

INTRODUCTION

The primary objective of the current study was to assess factors associated with Human Papillomavirus (HPV) vaccine initiation and compliance in a cohort of active duty US military service members (SM).

MATERIALS AND METHODS

We included active-duty participants aged 18-26 years from the Millennium Cohort Study, a longitudinal cohort study of over 200,000 military SMs. The eligible study population included 22,387 female SMs and 31,705 male SMs. Vaccination was assessed over the period 2006-2017. Logistic regression was used to estimate the odds of vaccine initiation and compliance (3 doses within a 1-year period) in relation to demographic, military, health, and behavioral characteristics.

RESULTS

Among female SMs, 37.8% initiated the vaccine and 40.2% of initiators completed the series within a year. Among male SMs, 3.9% initiated the vaccine and 22.1% of initiators completed the series within a year. Differences by sociodemographic factors, deployment status, branch of service, occupation, and smoking status-but not by selected mental health conditions-were observed.

CONCLUSION

HPV vaccination uptake is subpar across all military service branches. Certain subgroups of SMs could be targeted to increase overall HPV vaccine coverage in the US military population.

Military service experiences and reasons for service separation among lesbian, gay, and bisexual individuals in a large military cohort

BACKGROUND

The well-being of lesbian, gay, and bisexual (LGB) individuals is a topic of increasing concern within the military where significant institutional barriers, targeted aggression, and differential organizational policies such as "Don't Ask Don't Tell" have historically contributed to experiences of exclusion and discrimination. However, limited research has examined specific military and post-separation experiences among LGB service members and veterans. The goal of this study was to examine differences in military and service separation experiences by sexual orientation among a large representative sample of United States service members and veterans.

METHODS

Survey data from the 2016 Millennium Cohort Study follow-up questionnaire were used to assess sexual orientation and multiple outcomes of interest: military experiences (morale, feelings about the military, missed workdays) and service separation experiences (reasons for separation, post-separation employment). The associations between sexual orientation (LGB versus heterosexual) and each of these outcomes were evaluated in a series of adjusted logistic regression models, stratified by sex when interactions were observed.

RESULTS

Of the 99,599 participants, 3.4% identified as LGB. In adjusted models, LGB service members had significantly higher odds than heterosexual service members of feeling: unimpressed by the quality of unit leadership, unsupported by the military, and negative about the military overall. Bisexual women were more likely than heterosexual women to feel less unit camaraderie; both gay and bisexual men felt less camaraderie than heterosexual men. LGB veterans were more likely than heterosexual peers of the same sex to separate from service due to unplanned administrative reasons. Compared to heterosexual women, lesbian and bisexual women were more likely to separate from service due to dissatisfaction with promotions/pay and disability/medical reasons, while bisexual women specifically separated due to dissatisfaction with leadership and incompatibility with the military. Gay and bisexual men also reported separating due to incompatibility with the military, but only bisexual men were more likely to report separating due to disability/medical reasons compared to heterosexual men.

CONCLUSIONS

Less positive military- and separation-specific experiences disproportionately affected LGB service members in this study. Promoting inclusion and increasing support for LGB service members may improve satisfaction with military service and retention.

The Millennium Cohort Study: The First 20 Years of Research Dedicated to Understanding the Long-Term Health of US Service Members and Veterans

The Millennium Cohort Study, the US Department of Defense's largest and longest running study, was conceived in 1999 to investigate the effects of military service on service member health and well-being by prospectively following active duty, Reserve, and National Guard personnel from all branches during and following military service. In commemoration of the Study's 20th anniversary, this paper provides a summary of its methods, key findings, and future directions. Recruitment and enrollment of the first 5 panels occurred between 2001 and 2021. After completing a baseline survey, participants are requested to complete follow-up surveys every 3 to 5 years. Study research projects are categorized into 3 core portfolio areas (psychological health, physical health, and health-related behaviors) and several cross-cutting areas and have culminated in more than 120 publications to date. For example, some key Study findings include that specific military service-related factors (e.g., experiencing combat, serving in certain occupational subgroups) were associated with adverse health-related outcomes and that unhealthy behaviors and mental health issues may increase following the transition from military service to veteran status. The Study will continue to foster stakeholder relationships such that research findings inform and guide policy initiatives and health promotion efforts.

Longitudinal associations of military-related factors on self-reported sleep among U.S. service members

STUDY OBJECTIVES

Sleep loss is common in the military, which can negatively affect health and readiness; however, it is largely unknown how sleep varies over a military career. This study sought to examine the relationships between military-related factors and the new onset and reoccurrence of short sleep duration and insomnia symptoms.

METHODS

Millennium Cohort Study data were used to track U.S. military service members over time to examine longitudinal changes in sleep. Outcomes were self-reported average sleep duration (categorized as ≤5 hours, 6 hours, or 7-9 hours [recommended]) and/or insomnia symptoms (having trouble falling or staying asleep). Associations between military-related factors and the new onset and reoccurrence of these sleep characteristics were determined, after controlling for multiple health and behavioral factors.

RESULTS

Military-related factors consistently associated with an increased risk for new onset and/or reoccurrence of short sleep duration and insomnia symptoms included active duty component, Army or Marine Corps service, combat deployment, and longer than average deployment lengths. Military officers and noncombat deployers had decreased risk for either sleep characteristic. Time-in-service and separation from the military were complex factors; they lowered risk for ≤5 hours sleep but increased risk for insomnia symptoms.

CONCLUSIONS

Various military-related factors contribute to risk of short sleep duration and/or insomnia symptoms over time, although some factors affect these sleep characteristics differently. Also, even when these sleep characteristics remit, some military personnel have an increased risk of reoccurrence. Efforts to improve sleep prioritization and implement interventions targeting at-risk military populations, behaviors, and other significant factors are warranted.

Behavioral health and sleep problems among US Army veterinarians and veterinary technicians participating in the Millennium Cohort Study

OBJECTIVE

To determine the prevalences and relative odds of mental health problems, suicidal ideation, psychotropic medication use, problem drinking, trouble sleeping, and lack of social support among veterinarians and veterinary technicians, compared with other medical professionals, in the US Army.

SAMPLE

7,744 US Army personnel (957 officers [101 veterinarians and 856 physicians and dentists] and 6,787 enlisted personnel [334 veterinary technicians and 6,453 medics]) participating in the Millennium Cohort Study.

PROCEDURES

Eligible participants completed ≥ 1 survey while serving as an Army veterinarian, veterinary technician, physician, general dentist, or medic. Analysis methods including multivariable logistic regression adjusted for covariates and stratified by pay grade were used to investigate associations between each health-care occupation and outcomes of interest.

RESULTS

Veterinarians had higher reported prevalences of mental health problems, trouble sleeping, and lack of social support than did nontrauma physicians, trauma physicians, or dentists. On multivariable analysis, veterinarians had higher odds of mental health problems, trouble sleeping, and lack of social support, compared with physicians and dentists combined; odds for these outcomes were also higher for veterinarians, compared with various individual reference groups. Veterinary technicians had lower reported prevalence and lower odds of psychotropic medication use, compared with medics.

CONCLUSIONS AND CLINICAL RELEVANCE

Further examination of Army policies and organizational structures related to veterinarians may be warranted, along with the development of policies and interventions designed to improve mental health, sleep quality, and social support among military veterinarians.

Comparison of Posttraumatic Stress Disorder Checklist Instruments From Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition vs Fifth Edition in a Large Cohort of US Military Service Members and Veterans

IMPORTANCE

The definition of posttraumatic stress disorder (PTSD) changed markedly between the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) and DSM-5, creating challenges for studies and in medical settings spanning this transition.

OBJECTIVE

To evaluate the ability to compare and assess PTSD, based on DSM-IV and DSM-5 criteria, using PTSD Checklists (PCLs).

DESIGN, SETTING, AND PARTICIPANTS

This diagnostic study was conducted with survey data collected in October 2019, from the Millennium Cohort Study, a population-based US military cohort study. The population for the present study was restricted to a subset of initial web responders of the 2019 survey cycle, randomly assigned to 1 of 4 survey groups.

EXPOSURES

Each group received the DSM-IV and DSM-5 PCL (PCL-Civilian [PCL-C] version and PCL for DSM-5 [PCL-5]). PCL instruments were counterbalanced to control for order effects.

MAIN OUTCOMES AND MEASURES

Survey data were used to assess PTSD (using the PCL-C and PCL-5), major depressive disorder (using the Patient Health Questionnaire), generalized anxiety (using the Generalized Anxiety Disorder scale), and problem drinking (using the Patient Health Questionnaire). Demographic and military characteristics included age, sex, race/ethnicity, marital status, education, service branch, pay grade, enrollment panel, and military service status.

RESULTS

Among the 1921 participants (mean [SD] age, 50.1 [12.5] years), 1358 (70.7%) were men, 1638 (85.3%) were non-Hispanic White individuals, 1440 (75.0%) were married, and 1190 (61.9%) had at least a bachelor's degree; 295 (15.4%) had probable PTSD according to DSM-IV criteria with PCL-C compared with 286 (14.9%) using DSM-5 criteria with PCL-5 (κ = 0.77). There was substantial agreement between PCLs for probable PTSD based on DSM-IV criteria (295 [15.4%] with PCL-C; 316 [16.4%] with PCL-5; κ = 0.80) and DSM-5 criteria (286 [14.9%] with PCL-5; 258 [13.4%] with PCL-C; κ = 0.77). Estimated PTSD sum scores showed excellent agreement with observed scores. Using an established crosswalk, PCL-5 sum scores estimated with the PCL-C were similar to observed PCL-5 scores. Of the 17 corresponding items between the 2 instruments, 16 had substantial agreement. Appending 2 additional PCL-C items to the PCL-5 did not significantly alter estimates. The PCL-C and PCL-5 had nearly identical associations with comorbid conditions.

CONCLUSIONS AND RELEVANCE

The findings of this diagnostic study suggest that PTSD can be successfully assessed and compared over time with either PCL instrument in veteran and military populations.

Association of Combat Experiences With Suicide Attempts Among Active-Duty US Service Members

Importance

There is uncertainty about the role that military deployment experiences play in suicide-related outcomes. Most previous research has defined combat experiences broadly, and a limited number of cross-sectional studies have examined the association between specific combat exposure (eg, killing) and suicide-related outcomes.

Objective

To prospectively examine combat exposures associated with suicide attempts among active-duty US service members while accounting for demographic, military-specific, and mental health factors.

Design, Setting, and Participants

This cohort study analyzed data from the Millennium Cohort Study, an ongoing prospective longitudinal study of US service members from all military branches. Participants were enrolled in 4 phases from July 1, 2001, to April 4, 2013, and completed a self-administered survey at enrollment and every 3 to 5 years thereafter. The population for the present study was restricted to active-duty service members from the first 4 enrollment phases who deployed in support of the wars in Iraq and Afghanistan. Questionnaire data were linked with medical encounter data through September 30, 2015. Data analyses were conducted from January 10, 2017, to December 14, 2020.

Exposures

Combat exposure was examined in 3 ways (any combat experience, overall combat severity, and 13 individual combat experiences) using a 13-item self-reported combat measure.

Main Outcomes and Measures

Suicide attempts were identified from military electronic hospitalization and ambulatory medical encounter data using the International Classification of Diseases, Ninth Revision codes.

Results

Among 57 841 participants, 44 062 were men (76.2%) and 42 095 were non-Hispanic White individuals (72.8%), and the mean (SD) age was 26.9 (5.3) years. During a mean (SD) follow-up period of 5.6 (4.0) years, 235 participants had a suicide attempt (0.4%). Combat exposure, defined broadly, was not associated with suicide attempts in Cox proportional hazards time-to-event regression models after adjustments for demographic and military-specific factors; high combat severity and certain individual combat experiences were associated with an increased risk for suicide attempts. However, these associations were mostly accounted for by mental disorders, especially posttraumatic stress disorder. After adjustment for mental disorders, combat experiences with significant association with suicide attempts included being attacked or ambushed (hazard ratio [HR], 1.55; 95% CI, 1.16-2.06), seeing dead bodies or human remains (HR, 1.34; 95% CI, 1.01-1.78), and being directly responsible for the death of a noncombatant (HR, 1.81; 95% CI, 1.04-3.16).

Conclusions and Relevance

This study suggests that deployed service members who experience high levels of combat or are exposed to certain types of combat experiences (involving unexpected events or those that challenge moral or ethical norms) may be at an increased risk of a suicide attempt, either directly or mediated through a mental disorder.

Combat Experience, New-Onset Mental Health Conditions, and Posttraumatic Growth in U.S. Service Members

Objective: Studies examining posttraumatic growth (PTG) rely on surveys evaluating PTG in relation to prior traumatic experiences, resulting in psychometric problems due to the linkage of the dependent and independent variables. Few studies have assessed PTG following combat deployment while also controlling for mental health problems.Method: Longitudinal data on PTG, combat experience, and mental health were examined among U.S. Millennium Cohort Study deployers (n = 8732). Scores from a short-form (SF) version of the PTG inventory assessing current-state beliefs (C-PTGI-SF) independent of any predictor variables were assessed at time 1 (T1), before deployment, and change in scores were assessed approximately 3 years later after deployment at time 2 (T2). All participants screened negative for posttraumatic stress disorder (PTSD) and depression at T1.Results: Combat deployment severity was associated with a worsening of C-PTGI-SF scores at T2 among participants with moderate C-PTGI-SF scores at T1. A positive screen for comorbid PTSD/depression was associated with a worsening of C-PTGI-SF scores at T2 among participants with moderate or high C-PTGI-SF scores at T1. At T2, a strong inverse correlation was found between C-PTGI-SF scores and PTSD (r = -0.38) and depression (-0.41). Only 5% of participants who screened positive for a mental health problem at T2 (23/517) also experienced positive growth.Conclusions: These results challenge the clinical utility of the PTG construct. While PTG may be a useful framework for supporting trauma recovery on an individual basis, PTG does not appear to be distinct and independent from the negative psychological impact of traumatic experiences.

Prioritized Research for the Prevention, Treatment, and Reversal of Chronic Disease: Recommendations From the Lifestyle Medicine Research Summit

Declining life expectancy and increasing all-cause mortality in the United States have been associated with unhealthy behaviors, socioecological factors, and preventable disease. A growing body of basic science, clinical research, and population health evidence points to the benefits of healthy behaviors, environments and policies to maintain health and prevent, treat, and reverse the root causes of common chronic diseases. Similarly, innovations in research methodologies, standards of evidence, emergence of unique study cohorts, and breakthroughs in data analytics and modeling create new possibilities for producing biomedical knowledge and clinical translation. To understand these advances and inform future directions research, The Lifestyle Medicine Research Summit was convened at the University of Pittsburgh on December 4-5, 2019. The Summit's goal was to review current status and define research priorities in the six core areas of lifestyle medicine: plant-predominant nutrition, physical activity, sleep, stress, addictive behaviors, and positive psychology/social connection. Forty invited subject matter experts (1) reviewed existing knowledge and gaps relating lifestyle behaviors to common chronic diseases, such as cardiovascular disease, diabetes, many cancers, inflammatory- and immune-related disorders and other conditions; and (2) discussed the potential for applying cutting-edge molecular, cellular, epigenetic and emerging science knowledge and computational methodologies, research designs, and study cohorts to accelerate clinical applications across all six domains of lifestyle medicine. Notably, federal health agencies, such as the Department of Defense and Veterans Administration have begun to adopt "whole-person health and performance" models that address these lifestyle and environmental root causes of chronic disease and associated morbidity, mortality, and cost. Recommendations strongly support leveraging emerging research methodologies, systems biology, and computational modeling in order to accelerate effective clinical and population solutions to improve health and reduce societal costs. New and alternative hierarchies of evidence are also be needed in order to assess the quality of evidence and develop evidence-based guidelines on lifestyle medicine. Children and underserved populations were identified as prioritized groups to study. The COVID-19 pandemic, which disproportionately impacts people with chronic diseases that are amenable to effective lifestyle medicine interventions, makes the Summit's findings and recommendations for future research particularly timely and relevant.

Magnitude of problematic anger and its predictors in the Millennium Cohort

Background

Problematic anger is intense anger associated with elevated generalized distress and that interferes with functioning. It also confers a heightened risk for the development of mental health problems. In military personnel and veterans, previous studies examining problematic anger have been constrained by sample size, cross-sectional data, and measurement limitations.

Methods

The current study used Millennium Cohort survey data (N = 90,266) from two time points (2013 and 2016 surveys) to assess the association of baseline demographics, military factors, mental health, positive perspective, and self-mastery, with subsequent problematic anger.

Results

Overall, 17.3% of respondents reported problematic anger. In the fully adjusted logistic regression model, greater risk of problematic anger was predicted by certain demographic characteristics as well as childhood trauma and financial problems. Service members who were in the Army or Marines, active duty (vs. reserves/national guard), and previously deployed with high levels of combat had increased risk for problematic anger. Veterans were also more likely to report problematic anger than currently serving personnel. Mental health predictors included posttraumatic stress disorder (PTSD), major depressive disorder (MDD), and comorbid PTSD/MDD. Higher levels of positive perspective and self-mastery were associated with decreased risk of problematic anger.

Conclusion

Not only did 1 in 6 respondents report problematic anger, but risk factors were significant even after adjusting for PTSD and MDD, suggesting that problematic anger is more than an expression of these mental health problems. Results identify potential targets of early intervention and clinical treatment for addressing problematic anger in the military and veteran context.

Diversity and inclusion for the All of Us research program: A scoping review

The All of Us Research Program (All of Us) is a national effort to accelerate health research by exploring the relationship between lifestyle, environment, and genetics. It is set to become one of the largest research efforts in U.S. history, aiming to build a national resource of data from at least one million participants. All of Us aims to address the need for more diversity in research and set the stage for that diversity to be leveraged in precision medicine research to come. This paper describes how the program assessed demographic characteristics of participants who have enrolled in other U.S. biomedical research cohorts to better understand which groups are traditionally represented or underrepresented in biomedical research. We 1) reviewed the enrollment characteristics of national cohort studies like All of Us, and 2) surveyed the literature, focusing on key diversity categories essential to the program's enrollment aims. Based on these efforts, All of Us emphasizes enrollment of racial and ethnic minorities, and has formally designated the following additional groups as historically underrepresented: individuals-with inadequate access to medical care; under the age of 18 or over 65; with an annual household income at or below 200% of the federal poverty level; who have a cognitive or physical disability; have less than a high school education or equivalent; are intersex; identify as a sexual or gender minority; or live in rural or non-metropolitan areas. Research accounting for wider demographic variability is critical. Only by ensuring diversity and by addressing the very barriers that limit it, can we position All of Us to better understand and tackle health disparities.

Mental health, physical health, and health-related behaviors of U.S. Army Special Forces

Objectives

To prospectively examine the health and health-related behaviors of Army Special Forces personnel in comparison with two distinct, but functionally similar Army groups.

Methods

Special Forces, Ranger Qualified, and General Purposes Forces enrolled in the Millennium Cohort Study were identified using data from the Defense Manpower Data Center. Using prospective survey data (2001–2014), we estimated the association of Army specialization with mental health, social support, physical health, and health-related behaviors with multivariable regression models.

Results

Among the 5,392 eligible participants (84.4% General Purposes Forces, 10.0% Special Forces, 5.6% Ranger Qualified), Special Forces personnel reported the lowest prevalence of mental disorders, physical health problems, and unhealthy behaviors. In the multivariable models, Special Forces personnel were less likely to report mental health problems, multiple somatic symptoms, and unhealthy behaviors compared with General Purpose Forces infantrymen (odds ratios [OR]: 0.20–0.54, p-values < .01). Overall, Special Forces personnel were similar in terms of mental and physical health compared with Ranger Qualified infantrymen, but were less likely to sleep < 5 hours/night (OR: 0.60, 95% confidence intervals: 0.40, 0.92) and have 5 or more multiple somatic symptoms (OR: 0.69, 95% CI: 0.49, 0.98). Both Special Forces personnel and Ranger Qualified infantrymen engaged in more healthy behaviors compared with General Purpose Forces infantrymen (OR: 2.57–6.22, p-values<0.05). Engagement in more healthy behaviors reduced the odds of subsequent adverse health outcomes, regardless of specialization.

Conclusions

Army Special Forces personnel were found to be mentally and physically healthier than General Purpose Forces infantrymen, which may in part be due to their tendency to engage in healthy behaviors. Findings indicate that engagement in a greater number of healthy behaviors may reduce odds for subsequent adverse outcomes.

Longitudinal trajectories of comorbid PTSD and depression symptoms among U.S. service members and veterans

BACKGROUND

Posttraumatic stress disorder (PTSD) often co-occurs with other psychiatric disorders, particularly major depressive disorder (MDD). The current study examined longitudinal trajectories of PTSD and MDD symptoms among service members and veterans with comorbid PTSD/MDD.

METHODS

Eligible participants (n = 1704) for the Millennium Cohort Study included those who screened positive at baseline for both PTSD (PTSD Checklist-Civilian Version) and MDD (Patient Health Questionnaire). Between 2001 and 2016, participants completed a baseline assessment and up to 4 follow-up assessments approximately every 3 years. Mixture modeling simultaneously determined trajectories of comorbid PTSD and MDD symptoms. Multinomial regression determined factors associated with latent class membership.

RESULTS

Four distinct classes (chronic, relapse, gradual recovery, and rapid recovery) described symptom trajectories of PTSD/MDD. Membership in the chronic class was associated with older age, service branch, deployment with combat, anxiety, physical assault, disabling injury/illness, bodily pain, high levels of somatic symptoms, and less social support.

CONCLUSIONS

Comorbid PTSD/MDD symptoms tend to move in tandem, and, although the largest class remitted symptoms, almost 25% of participants reported chronic comorbid symptoms across all time points. Results highlight the need to assess comorbid conditions in the context of PTSD. Future research should further evaluate the chronicity of comorbid symptoms over time.

Posttraumatic Stress Disorder Symptom Association With Subsequent Risky and Problem Drinking Initiation

OBJECTIVES

Posttraumatic stress disorder (PTSD) and unhealthy alcohol use are commonly associated conditions. It is unknown whether specific symptoms of PTSD are associated with subsequent initiation of unhealthy alcohol use.

METHODS

Data from the first 3 enrollment panels (n = 151,567) of the longitudinal Millennium Cohort Study of military personnel were analyzed (2001-2012). Complementary log-log models were fit to estimate whether specific PTSD symptoms and symptom clusters were associated with subsequent initiation of 2 domains of unhealthy alcohol use: risky and problem drinking (experience of 1 or more alcohol-related consequences). Models were adjusted for other PTSD symptoms and demographic, service, and health-related characteristics.

RESULTS

Eligible study populations included those without risky (n = 31,026) and problem drinking (n = 67,087) at baseline. In adjusted analyses, only 1 PTSD symptom-irritability/anger-was associated with subsequent increased initiation of risky drinking (relative risk [RR] 1.05, 95% confidence interval [CI] 1.00-1.09) at least 3 years later. Two symptom clusters (dysphoric arousal [RR 1.17, 95% CI 1.11-1.23] and emotional numbing [RR 1.30, 95% CI 1.22-1.40]) and 5 symptoms (restricted affect [RR 1.13, 95% CI 1.08-1.19], sense of foreshortened future [RR 1.12, 95% CI 1.06-1.18], exaggerated startle response [RR 1.07, 95% CI 1.01-1.13], sleep disturbance [RR 1.11, 95% CI 1.07-1.15], and irritability/anger [RR 1.12, 95% CI 1.07-1.17]) were associated with subsequent initiation of problem drinking.

CONCLUSIONS

Findings suggest that specific PTSD symptoms and symptom clusters are associated with subsequent initiation of unhealthy alcohol use.

Development of Longitudinal Data Analysis in Mental Health Research For Military Service Members

INTRODUCTION

Since the 1991 Gulf War, mental health conditions of military Service members have received increasing public attention and are a major focus for the U.S. government. A substantial proportion of military health research has been devoted to examining the pattern of change over time in mental health symptoms and diagnostic status among Service members. Unfortunately, many researchers continue to use somewhat obsolete methods to analyze trends and transitions in mental health, despite advances in statistical methodology that permit attention to the unique features inherent in longitudinal data.

MATERIALS AND METHODS

This article defines and describes data features and structures, and basic specifications of longitudinal data analysis to military health researchers. In particular, we highlight the respective impacts of missing data and intra-individual correlation on longitudinal data analysis. Based on the descriptions of the basic features in longitudinal data, we introduce several popular techniques to analyze a variety of longitudinal data types.

RESULTS

We demonstrate that traditional analytic techniques do not properly account for missing data and intra-individual correlation inherent in longitudinal data. Failure to use correct, appropriate models and methods can result in major bias in analytic results and mental health predictions.

CONCLUSIONS

Failure to use correct, appropriate models and methods in longitudinal data analysis can have unfortunate repercussions on a military health system that needs accurate findings to support valid policy decisions. By applying adequate models and methods, military health researchers will be able to better understand the complex interactions of biological, psychological, and social factors on mental health trends and transitions among military Service members.

The association of alcohol consumption patterns with self-rated physical health and psychiatric distress among Afghanistan- and Iraq-era U.S. veterans

Alcohol misuse is associated with negative mental and physical health outcomes, which presents a public health concern in veterans. However, less is known regarding outcomes among veterans with low to moderate alcohol consumption. This study included veterans with military service in Iraq and/or Afghanistan (N = 1083) who resided in the VA Mid-Atlantic region catchment area (North Carolina, Virginia, and parts of West Virginia). Participants completed a mailed survey that inquired about demographics, past-year alcohol consumption, self-rated physical health, and psychiatric symptoms. Logistic regression was used to evaluate associations between alcohol consumption and posttraumatic stress disorder (PTSD), depression, and self-rated physical health. In both bivariate results and adjusted models, non-drinkers and hazardous drinkers were more likely to endorse clinically significant PTSD and depression symptoms than moderate drinkers. Moderate drinkers were also less likely to report fair/poor health, after adjusting for demographics and psychiatric symptoms. Results overall showed a U-shaped curve, such that moderate alcohol use was associated with lower rates of mental health problems and fair/poor health. While the VA routinely screens for alcohol misuse, current results suggest that non-drinkers are also at risk for poor mental and physical health.

Military service, deployments, and exposures in relation to amyotrophic lateral sclerosis survival

BACKGROUND

Military veterans may have higher rates of amyotrophic lateral sclerosis (ALS) mortality than non-veterans. Few studies, with sparse exposure information and mixed results, have studied relationships between military-related factors and ALS survival. We evaluated associations between military-related factors and ALS survival among U.S. military veteran cases.

METHODS

We followed 616 medical record-confirmed cases from enrollment (2005-2010) in the Genes and Environmental Exposures in Veterans with Amyotrophic Lateral Sclerosis study until death or July 25, 2013, whichever came first. We ascertained vital status information from several sources within the Department of Veterans Affairs. We obtained information regarding military service, deployments, and 39 related exposures via standardized telephone interviews. We used Cox proportional hazards regression models to estimate hazard ratios (HRs) and 95% confidence intervals. We adjusted for potential confounding and missing covariate data biases via inverse probability weights. We also used inverse probability weights to adjust for potential selection bias among a case group that included a disproportionate number of long-term survivors at enrollment.

RESULTS

We observed 446 deaths during 24,267 person-months of follow-up (median follow-up: 28 months). Survival was shorter for cases who served before 1950, were deployed to World War II, or mixed and applied burning agents, with HRs between 1.58 and 2.57. Longer survival was associated with exposure to: paint, solvents, or petrochemical substances; local food not provided by the Armed Forces; or burning agents or Agent Orange in the field with HRs between 0.56 and 0.73.

CONCLUSIONS

Although most military-related factors were not associated with survival, associations we observed with shorter survival are potentially important because of the large number of military veterans.

Caffeine Use among Active Duty Navy and Marine Corps Personnel

Data from the National Health and Nutrition Examination Survey (NHANES) indicate 89% of Americans regularly consume caffeine, but these data do not include military personnel. This cross-sectional study examined caffeine use in Navy and Marine Corps personnel, including prevalence, amount of daily consumption, and factors associated with use. A random sample of Navy and Marine Corps personnel was contacted and asked to complete a detailed questionnaire describing their use of caffeine-containing substances, in addition to their demographic, military, and lifestyle characteristics. A total of 1708 service members (SMs) completed the questionnaire. Overall, 87% reported using caffeinated beverages ≥1 time/week, with caffeine users consuming a mean ± standard error of 226 ± 5 mg/day (242 ± 7 mg/day for men, 183 ± 8 mg/day for women). The most commonly consumed caffeinated beverages (% users) were coffee (65%), colas (54%), teas (40%), and energy drinks (28%). Multivariable logistic regression modeling indicated that characteristics independently associated with caffeine use (≥1 time/week) included older age, white race/ethnicity, higher alcohol consumption, and participating in less resistance training. Prevalence of caffeine use in these SMs was similar to that reported in civilian investigations, but daily consumption (mg/day) was higher.

Longitudinal Associations Among Posttraumatic Stress Disorder, Disordered Eating, and Weight Gain in Military Men and Women

Obesity is a major health problem in the United States and a growing concern among members of the military. Posttraumatic stress disorder (PTSD) has been associated with overweight and obesity and may increase the risk of those conditions among military service members. Disordered eating behaviors have also been associated with PTSD and weight gain. However, eating disorders remain understudied in military samples. We investigated longitudinal associations among PTSD, disordered eating, and weight gain in the Millennium Cohort Study, which includes a nationally representative sample of male (n = 27,741) and female (n = 6,196) service members. PTSD at baseline (time 1; 2001-2003) was associated with disordered eating behaviors at time 2 (2004-2006), as well as weight change from time 2 to time 3 (2007-2008). Structural equation modeling results revealed that the association between PTSD and weight change from time 2 to time 3 was mediated by disordered eating symptoms. The association between PTSD and weight gain resulting from compensatory behaviors (vomiting, laxative use, fasting, overexercise) was significant for white participants only and for men but not women. PTSD was both directly and indirectly (through disordered eating) associated with weight change. These results highlight potentially important demographic differences in these associations and emphasize the need for further investigation of eating disorders in military service members.

Obesity and associated adverse health outcomes among US military members and veterans: Findings from the millennium cohort study

OBJECTIVE

To assess the prevalence of obesity and associated health outcomes among US service members and veterans.

METHODS

Data from three survey cycles (2001-2008) of the Millennium Cohort Study were used to examine the prevalence of obesity and associated health outcomes.

RESULTS

Of the 42,200 individuals, 25% were of normal weight in 2007/2008. Rates of obesity were significantly higher among veterans (32%) compared with service members (20%). Over a 7-year period, obesity rates doubled among both service members (10%-20%) and veterans (14%-32%). Participants with obesity were significantly more likely to be male, older, less educated, in the Army or Navy, and separated/retired from the military. Hypertension, diabetes, and sleep apnea were significantly more common among individuals with obesity compared with participants with normal weight (all P < 0.05). Individuals with obesity also had significantly higher rates of depression and post-traumatic stress disorder than individuals with normal weight and had lower mental and physical functional scores (all P < 0.05).

CONCLUSIONS

These findings indicate an urgent need to enhance strategies for preventing and reducing excess weight gain within the military and veteran populations. Such strategies should aim to ensure a fit military force and promote health after military service.

Military service, deployments, and exposures in relation to amyotrophic lateral sclerosis etiology

BACKGROUND

Factors underlying a possible excess of amyotrophic lateral sclerosis (ALS) among military veterans remain unidentified. Limitations of previous studies on this topic include reliance on ALS mortality as a surrogate for ALS incidence, low statistical power, and sparse information on military-related factors.

OBJECTIVES

We evaluated associations between military-related factors and ALS using data from a case-control study of U.S. military veterans.

METHODS

From 2005 to 2010, we identified medical record-confirmed ALS cases via the National Registry of Veterans with ALS and controls via the Veterans Benefits Administration's Beneficiary Identification and Records Locator System database. In total, we enrolled 621 cases and 958 frequency-matched controls in the Genes and Environmental Exposures in Veterans with Amyotrophic Lateral Sclerosis study. We collected information on military service and deployments and 39 related exposures. We used unconditional logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs). We used inverse probability weighting to adjust for potential bias from confounding, missing covariate data, and selection arising from a case group that disproportionately included long-term survivors and a control group that may or may not differ from U.S. military veterans at large.

RESULTS

The odds of ALS did not differ for veterans of the Air Force, Army, Marines, and Navy. We found higher odds of ALS for veterans whose longest deployment was World War II or the Korean War and a positive trend with total years of all deployments (OR=1.27; 95% CI: 1.06, 1.52). ALS was positively associated with exposure to herbicides for military purposes, nasopharyngeal radium, personal pesticides, exhaust from heaters or generators, high-intensity radar waves, contaminated food, explosions within one mile, herbicides in the field, mixing and application of burning agents, burning agents in the field, and Agent Orange in the field, with ORs between 1.50 and 7.75.

CONCLUSIONS

Although our results need confirmation, they are potentially important given the large number of U.S. military veterans, and they provide clues to potential factors underlying the apparent increase of ALS in veteran populations.

Sexual Trauma and Adverse Health and Occupational Outcomes Among Men Serving in the U.S. Military

Although absolute counts of U.S. service men who experience sexual trauma are comparable to service women, little is known about the impact of sexual trauma on men. The association of recent sexual trauma (last 3 years) with health and occupational outcomes was investigated using longitudinal data (2004-2013) from the Millennium Cohort Study. Of 37,711 service men, 391 (1.0%) reported recent sexual harassment and 76 (0.2%) sexual assault. In multivariable models, sexual harassment or assault, respectively, was associated with poorer mental health: AOR = 1.60, 95% CI [1.22, 2.12], AOR = 4.39, 95% CI [2.40, 8.05]; posttraumatic stress disorder: AOR = 2.50, 95% CI [1.87, 3.33], AOR = 6.63, 95% CI [3.65, 12.06]; depression: AOR = 2.37, 95% CI [1.69, 3.33], AOR = 5.60, 95% CI [2.83, 11.09]; and multiple physical symptoms: AOR = 2.22, 95% CI [1.69, 2.92]; AOR = 3.57, 95% CI [1.98, 6.42], after adjustment for relevant covariates. Sexual harassment was also associated with poorer physical health: AOR = 1.68, 95% CI [1.27, 2.22]. Men who reported sexual trauma were more likely to have left military service: AOR = 1.60, 95% CI [1.14, 2.24], and be disabled/unemployed postservice: AOR = 1.76, 95% CI [1.02, 3.02]. Results suggest that sexual trauma was significantly associated with adverse health and functionality extending to postmilitary life. Findings support the need for developing better prevention strategies and services to reduce the burden of sexual trauma on service men.

Longitudinal assessment of mental disorders, smoking, and hazardous drinking among a population-based cohort of US service members

OBJECTIVES

Combat exposure is known to increase the risk for mental disorders; however, less is known about the temporal relationship between mental disorders and alcohol misuse or smoking. To better understand these interrelationships, this study investigated mental disorders in association with hazardous drinking and cigarette smoking.

METHODS

Using data from a large population-based military cohort, standardized instruments were used to screen for posttraumatic stress disorder, depression, panic, and other anxiety syndromes. Self-reported use of cigarettes and hazardous drinking was also assessed. Subjects were classified as having "new-onset," "persistent," or "resolved" mental disorders and health risk behaviors on the basis of screening results from baseline to follow-up (n = 50,028). Multivariable logistic regression models were used to investigate temporal patterns between the development of mental disorders and the uptake of smoking or hazardous drinking.

RESULTS

The strongest associations of new-onset mental disorders were among those who newly reported smoking or hazardous drinking (odds ratio [OR], 1.82; 95% confidence interval [CI], 1.28-2.59 and OR, 2.49; 95% CI, 2.15-2.89, respectively), even after adjustment for combat deployment experience. In addition, persistent smokers and hazardous drinkers had elevated odds for developing a mental disorder at follow-up.

CONCLUSIONS

This study demonstrates a positive association between the onset of mental disorders with the uptake of smoking and hazardous drinking and the likelihood that multiple temporal sequence patterns exist to explain the relationship between mental disorders and hazardous drinking and smoking. Clinical approaches to mitigate deployment-related mental disorders should include alcohol and tobacco-related assessments and interventions.

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.

Recent Sexual Trauma and Adverse Health and Occupational Outcomes Among U.S. Service Women

Sexual trauma is prevalent among military women, but data on potential effects are needed. The association of sexual trauma with health and occupational outcomes was investigated using longitudinal data from the Millennium Cohort Study. Of 13,001 U.S. service women, 1,364 (10.5%) reported recent sexual harassment and 374 (2.9%) recent sexual assault. Women reporting recent sexual harassment or assault were more likely to report poorer mental health: OR = 1.96, 95% CI [1.71, 2.25], and OR = 3.45, 95% CI [2.67, 4.44], respectively. They reported poorer physical health: OR = 1.39, 95% CI [1.20, 1.62], and OR = 1.39, 95% CI [1.04, 1.85], respectively. They reported difficulties in work/activities due to emotional health: OR = 1.80, 95% CI [1.59, 2.04], and OR = 2.70, 95% CI [2.12, 3.44], respectively. They also reported difficulties with physical health: OR = 1.55, 95% CI [1.37, 1.75], and OR = 1.52 95% CI [1.20, 1.91], respectively, after adjustment for demographic, military, health, and prior sexual trauma characteristics. Recent sexual harassment was associated with demotion, OR = 1.47, 95% CI [1.12, 1.93]. Findings demonstrated that sexual trauma represents a potential threat to military operational readiness and draws attention to the importance of prevention strategies and services to reduce the burden of sexual trauma on military victims.

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.

Longitudinal Investigation of Smoking Initiation and Relapse Among Younger and Older US Military Personnel

OBJECTIVES

We examined whether military service, including deployment and combat experience, were related to smoking initiation and relapse.

METHODS

We included older (panel 1) and younger (panel 2) participants in the Millennium Cohort Study. Never smokers were followed for 3 to 6 years for smoking initiation, and former smokers were followed for relapse. Complementary log-log regression models estimated the relative risk (RR) of initiation and relapse by military exposure while adjusting for demographic, health, and lifestyle factors.

RESULTS

Deployment with combat experience predicted higher initiation rate (panel 1: RR = 1.44; 95% confidence interval [CI] = 1.28, 1.62; panel 2: RR = 1.26; 95% CI = 1.04, 1.54) and relapse rate (panel 1 only: RR = 1.48; 95% CI = 1.36, 1.62). Depending on the panel, previous mental health disorders, life stressors, and other military and nonmilitary characteristics independently predicted initiation and relapse.

CONCLUSIONS

Deployment with combat experience and previous mental disorder may identify military service members in need of intervention to prevent smoking initiation and relapse.

Post-traumatic stress disorder predicts future weight change in the Millennium Cohort Study

OBJECTIVE

To prospectively examine the association between post-traumatic stress disorder (PTSD) and weight change.

METHODS

Longitudinal analysis techniques were used to examine data (2001-2008) from Millennium Cohort Study participants, consisting of U.S. service members and veterans. Using the PTSD Checklist-Civilian Version, PTSD was assessed as none, resolved, new onset, or persistent. Subsequent weight change was assessed as stable (≤3% loss or gain), >3% weight loss, >3% but <10% weight gain, and ≥10% weight gain.

RESULTS

Of the 38,352 participants, 2391 (6.2%) had PTSD (838 resolved, 1024 new onset, and 529 persistent), and 11% of participants subsequently had ≥10% weight gain. In multivariable models, PTSD was associated with higher odds of ≥10% weight gain (new onset OR: 1.44 [95% CI: 1.20-1.73]; persistent OR: 1.51 [CI: 1.17-1.96]; resolved OR: 1.30 [CI: 1.05-1.60]) compared with those without PTSD. New-onset and persistent PTSD were also associated with higher odds of >3% weight loss (OR: 1.41 [CI: 1.17-1.71]; OR: 1.42 [CI: 1.09-1.86], respectively).

CONCLUSIONS

PTSD is independently associated with a higher risk of weight gain and loss, the former of which leads to a higher prevalence of overweight and obesity and a higher risk of comorbidities associated with excessive body adiposity.

Chronic multisymptom illness: a comparison of Iraq and Afghanistan deployers with veterans of the 1991 Gulf War

Symptoms and illnesses reported by veterans of the 1991 Gulf War era are a cause of potential concern for those military members who have deployed to the Gulf region in support of more recent contingency operations in Iraq and Afghanistan. In the present study, we quantified self-reported symptoms from participants in the Millennium Cohort Study, a prospective study representing all US service branches, including both active duty and Reserve/National Guard components (2001-2008). Self-reported symptoms were uniquely compared with those in a cohort of subjects from the 1991 Gulf War to gain context for the present report. Symptoms were then aggregated to identify cases of chronic multisymptom illness (CMI) based on the case definition from the Centers for Disease Control and Prevention. The prevalence of self-reported CMI symptoms was compared with that collected in 1997-1999 from a study population of US Seabees from the 1991 Gulf War, as well as from deployed and nondeployed subgroups. Although overall symptom reporting was much less in the Millennium Cohort than in the 1991 Gulf War cohort, a higher prevalence of reported CMI was noted among deployed compared with nondeployed contemporary cohort members. An increased understanding of coping skills and resilience and development of well-designed screening instruments, along with appropriate clinical and psychological follow-up for returning veterans, might help to focus resources on early identification of potential long-term chronic disease manifestations.

Suicide Prevention

Suicide is a public health problem affecting people across the lifespan. It is currently the 10th leading cause of death, with rates having remained relatively flat for the past century. This article summarizes the problem of suicide and suicidal behavior along with suicide prevention efforts in the United States. Part 1 provides an overview of the epidemiology of suicide, including groups most at risk of suicide and suicidal behavior. Part 2 provides a review of common risk factors, organized by developmental life stage. A brief discussion of the lesser well-researched area of protective factors follows. Part 3 provides an overview of suicide prevention today, including the major types of prevention strategies, their successes, including means restriction, quality improvement in behavioral services, and comprehensive programs; and limitations to date, such as a lack of evidence for impact on actual deaths or behavior, small sample sizes, and low base rates. Finally, part 4 discusses challenges and future directions with an eye toward the great many opportunities that exist for prevention.

Impact of Combat Deployment and Posttraumatic Stress Disorder on Newly Reported Coronary Heart Disease Among US Active Duty and Reserve Forces

Background—

The recent conflicts in Iraq and Afghanistan have exposed thousands of service members to intense stress, and as a result, many have developed posttraumatic stress disorder (PTSD). The role of military deployment experiences and PTSD in coronary heart disease (CHD) is not well defined, especially in young US service members with recent combat exposure.

Methods and Results—

We conducted a prospective cohort study to investigate the relationships between wartime experiences, PTSD, and CHD. Current and former US military personnel from all service branches participating in the Millennium Cohort Study during 2001 to 2008 (n=60 025) were evaluated for newly self-reported CHD. Electronic medical record review for International Classification of Diseases, Ninth Revision, Clinical Modification codes for CHD was conducted among a subpopulation of active duty members (n=23 794). Logistic regression models examined the associations between combat experiences and PTSD with CHD with adjustment for established CHD risk factors. A total of 627 participants (1.0%) newly reported CHD over an average of 5.6 years of follow-up. Deployers with combat experiences had an increased odds of newly reporting CHD (odds ratio, 1.63; 95% confidence interval, 1.11–2.40) and having a diagnosis code for new-onset CHD (odds ratio, 1.93; 95% confidence interval, 1.31–2.84) compared with noncombat deployers. Screening positive for PTSD symptoms was associated with self-reported CHD before but not after adjustment for depression and anxiety and was not associated with a new diagnosis code for CHD.

Conclusions—

Combat deployments are associated with new-onset CHD among young US service members and veterans. Experiences of intense stress may increase the risk for CHD over a relatively short period among young adults.

Self-reported infertility among male and female veterans serving during Operation Enduring Freedom/Operation Iraqi Freedom

BACKGROUND

Infertility is associated with psychosocial distress and is a growing public health concern. Our objective was to report the prevalence of lifetime history of infertility among men and women Veterans.

METHODS

We used data from the U.S. Department of Veterans Affairs National Health Study for a New Generation of U.S. Veterans, a nationally representative survey of Veterans serving during Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF). The primary dependent variables were self-reported lifetime history of infertility among Veterans and their partners, defined as trying unsuccessfully to become pregnant for at least 12 months, and seeking medical help for infertility. Multiple logistic regression was used to determine whether gender was associated with lifetime history of infertility or seeking medical help for infertility, after adjusting for sociodemographic and military characteristics. All analyses were weighted to account for the complex survey design and nonresponse.

RESULTS

Among the 20,370 Veterans (16,056 men; 4,314 women) in our final analytic sample, the prevalence of lifetime history of infertility was 15.8% for women and 13.8% for men. After adjusting for age, ever married, education, race/ethnicity, component, branch of service, and deployment to OEF/OIF, compared with men, women Veterans had similar odds of lifetime history of infertility (odds ratio [OR] 1.07; 95% confidence interval [CI] 0.94, 1.20), but increased odds of seeking medical help for infertility (OR 1.35; 95% CI 1.06, 1.72).

CONCLUSIONS

Women Veterans are more likely than their male counterparts to seek care for infertility, and given their increasing numbers, the demand for infertility evaluation and care within Veterans' Affairs may increase.

The Association of Predeployment and Deployment-Related Factors on Dimensions of Postdeployment Wellness in U.S. Military Service Members

Purpose.

To assess the effects of predeployment and deployment-related factors on dimensions of wellness following deployment.

Design.

Prospective longitudinal study. The dependent variable was dimensions of wellness. Independent variables were measured in terms of modifiable, nonmodifiable, and military factors, such as sex, race/ethnicity, service branch, smoking status, and combat experience.

Setting.

A large military cohort participating in the Millennium Cohort Study.

Subjects.

Included 10,228 participants who deployed in support of the operations in Iraq and Afghanistan.

Measures.

Dimensions of wellness were measured by using standardized instruments assessing self-reported physical health, mental health, and stress. Covariates were measured by using self-reported and electronic data.

Analysis.

Factors of postdeployment wellness were assessed by using ordinal logistic regression.

Results.

Most participants (78.7%) were categorized as “moderately well” post deployment. Significant modifiable predeployment predictors of postdeployment wellness included normal/underweight body mass index (odds ratio [OR] = 1.72, p < .05). Military factors significantly associated with wellness included not experiencing combat (OR = .56, p < .05), member of Air Force (OR = 2.02, p < .05) or Navy/Coast Guard (OR = 1.47, p < .05), and combat specialist occupation (OR = 1.22, p < .05).

Conclusion.

Multiple modifiable factors associated with postdeployment wellness were identified, which may help inform medical and military leadership on potential strategies to ensure a well force. Those trained in combat roles were more likely to be well post deployment though this apparent benefit was not conferred onto those reporting combat experiences.