A Meta-Analysis of Risk Factors for Combat-Related PTSD among Military Personnel and Veterans

Post-traumatic stress disorder (PTSD), a complex and chronic disorder caused by exposure to a traumatic event, is a common psychological result of current military operations. It causes substantial distress and interferes with personal and social functioning. Consequently, identifying the risk factors that make military personnel and veterans more likely to experience PTSD is of academic, clinical, and social importance. Four electronic databases (PubMed, Embase, Web of Science, and PsycINFO) were used to search for observational studies (cross-sectional, retrospective, and cohort studies) about PTSD after deployment to combat areas. The literature search, study selection, and data extraction were conducted by two of the authors independently. Thirty-two articles were included in this study. Summary estimates were obtained using random-effects models. Subgroup analyses, sensitivity analyses, and publication bias tests were performed. The prevalence of combat-related PTSD ranged from 1.09% to 34.84%. A total of 18 significant predictors of PTSD among military personnel and veterans were found. Risk factors stemming from before the trauma include female gender, ethnic minority status, low education, non-officer ranks, army service, combat specialization, high numbers of deployments, longer cumulative length of deployments, more adverse life events, prior trauma exposure, and prior psychological problems. Various aspects of the trauma period also constituted risk factors. These include increased combat exposure, discharging a weapon, witnessing someone being wounded or killed, severe trauma, and deployment-related stressors. Lastly, lack of post-deployment support during the post-trauma period also increased the risk of PTSD. The current analysis provides evidence of risk factors for combat-related PTSD in military personnel and veterans. More research is needed to determine how these variables interact and how to best protect against susceptibility to PTSD.     

Prediction model for attrition from a combat unit training program

The purpose of this study was to develop a prediction model for the attrition rate of soldiers from an 8-month advanced military training program based on physical and psychological factors. Two groups of 59 and 61 healthy, fit young men (18.7 ± 0.7 years) entering a rigorous combat unit training program in the Israeli Defense Forces were recruited to participate in this study. Data on anthropometrics, nutrition, blood measures (chemical and hematological), fitness, and bone quality were collected on the induction day. Psychological questionnaires were completed at 3 time points: baseline--upon entry to basic training (BT), after 2 months, and after 4 months (completion of BT). The data of the 2 groups were pooled together for the analysis and to construct a new prediction model for attrition (Patt) as follows: Patt = 11.20 - 0.87Est(Com4) - 0.72Sc - 0.23%BF; where Est(Com4) is commander appreciation as perceived by the soldier after 4-month BT, Sc is a self-confidence grade, and %BF is the % body fat. The new suggested model successfully predicted 75.3% of subject attrition in the combat unit. We therefore concluded that Special Forces recruits with relatively low body fat percentage (%BF), low self-esteem, and who feel unappreciated by their commander are at a higher dropout risk from a rigorous combat training program.     

Risk Assessment in Navy Deployment Toxicology

The risk assessment process is a critical function for deployment toxicology research. It is essential to the decision making process related to establishing risk reduction procedures and for formulating appropriate exposure levels to protect naval personnel from potentially hazardous chemicals in the military that could result in a reduction in readiness operations. These decisions must be based on quality data from well-planned laboratory animal studies that guide the judgements, which result in effective risk characterization and risk management. The process of risk assessment in deployment toxicology essentially uses the same principles as civilian risk assessment, but adds activities essential to the military mission, including intended and unintended exposure to chemicals and chemical mixtures. Risk assessment and Navy deployment toxicology data are integrated into a systematic and well-planned approach to the organization of scientific information. The purpose of this paper is to outline the analytical framework used to develop strategies to protect the health of deployed Navy forces.     

The role of botanists during World War II in the Pacific theatre

During World War II some professional botanists and graduate students who were drafted, enlisted, or commissioned in the armed forces were fortunate to be able to use their training directly or indirectly. This was especially true for the Pacific theatre. Others served their country as civilians. The roles of botanists in the military ranged from teaching or research to participation in combat or support operations. A few botanists in uniform, in spite of their occupational obligations, were able to collect botanical specimens and were encouraged to do so by civilian museum personnel. The best known projects for botanists as civilians involved the search for native supplies of strategic raw materials, particularlyCinchona andHevea, whileCryptostegia and Guayule, as possible sources of latex, were grown on plantations and studied in detail. Tropical problems of fungal deterioration of fabrics and optical equipment involved primarily civilian botanists in both military and academic laboratories. Some older botanists and those deferred for marital, dependent, or physical reasons served as instructors in regular academic programs or the special college programs for military personnel.     

Effects of Coffee Consumption on Oxidative Susceptibility of Low-Density Lipoproteins and Serum Lipid Levels in Humans

Since little is known about how coffee intake affects low-density lipoprotein (LDL) oxidative susceptibility and serum lipid levels, we conducted an in vivo study in 11 healthy male students of Wakayama Medical University aged between 20 and 31 years fed an average Japanese diet. On days 1-7 of the study, the subjects drank mineral water. On day 7, the subjects began drinking coffee, 24 g total per day, for one week. This was followed by a one week "washout period" during which mineral water was consumed. Fasting peripheral venous blood samples were taken at the end of each one-week period. LDL oxidation lag time was approximately 8% greater (p < 0.01) after the coffee drinking period than the other periods. Serum levels of total cholesterol and LDL-cholesterol (LDL-C) and malondialdehyde (MDA) as thiobarbituric acid reactive substances (TBARS) were significantly decreased after the coffee drinking period. Finally, regular coffee ingestion may favorably affect cardiovascular risk status by modestly reducing LDL oxidation susceptibility and decreasing LDL-cholesterol and MDA levels.     

The injured mind in the UK Armed Forces

The mental health of the UK Armed Forces is a topic much debated by healthcare professionals, politicians and the media. While the current operations in Afghanistan, and the recent conflict in Iraq, are relevant to this debate, much of what is known about the effects of war upon the psyche still derives from the two World Wars. This paper will examine the historical and contemporary evidence about why it is that some Service personnel suffer psychological injuries during their military service and others do not. The paper will also consider some of the strategies that today's Armed Forces have put in place to mitigate the effects of sending military personnel into danger.     

US Coast Guard collision at sea

The collision between the USCGC Cuyahoga and the motor vessel Santa Cruz II resulted in psychological distress among the Coast Guard crewmen. The US Navy Special Psychiatric Rapid Intervention Team (SPRINT) was activated to provide mental health services to the Coast Guard survivors and others who had been affected by the disaster. The psychiatric records of the 18 survivors were examined and summarized, and combined with anecdotal comments made by SPRINT members. The most prominent psychological reactions among the survivors were shock, anger, sadness, and guilt. Spouses of the survivors dealt with bereavement and strove to understand their husbands' reactions. Variables identified by the SPRINT as being important to their success were communication with and support from the training center command, assurances of confidentiality to the survivors, and commencement of their work almost immediately following the collision.     

Muscles advance the teeth in sand dollars and other sea urchins

We demonstrate the action of the dental promoter muscles in advancing the continuously growing teeth of sand dollars and sea urchins. Teeth wear at the occlusal end, while new calcite is added to the opposite end. Dental ligaments rigidly hold teeth during chewing, but soften and reform during advancement. The source of forces that advance the teeth was unknown until our discovery of the dental promoter muscles. The muscles, which underly the tooth, attach centrally to the stereom of the pyramid of the Aristotle''s lantern (jaw) and peripherally to a membrane that covers the distal end of the tooth. The muscles shorten along an axis nearly parallel to the long axis of the tooth. We stimulated contraction by addition of acetylcholine, with increasing concentrations of acetylcholine generating higher forces. Forces exerted by this muscle are appropriate for its size and are 1000 times lower than forces exerted by interpyramidal muscles that generate chewing forces. In sand dollars, a single muscle contraction of the dental promoter muscle can account for half the mean daily advancement of the teeth.     

The response of growing rats to a diet supplemented with the antibiotic ampicillin.

Ampicillin was included (25 mg/litre) in the drinking water supplied to growing rats over periods of 2,3,4,5,6,7 or 8 weeks. 32 rats were used in each experimental period, half being given the antibiotic and half being left as controls. The antibiotic increased the liveweight gain in each period, the results being significant after the 2- and 4-week feeding periods. Significant decreases were observed in the average percentage weights of the spleens of the rats given the antibiotic at the end of all the feeding periods except one. The few other significant changes in the percentage weights of other organs were, with one exception, noted at or before the end of the 4th week.     

“Feeling worthless”: An ethnographic investigation of depression and problem drinking at the flathead reservation

The study of depression, drinking and suicidality has long preoccupied students of American Indian life, in part because of the assumed connection between these specific forms of psychiatric distress and generalized demoralization. Given the significant variation in suicidal behavior and prevalence rates intertribally, this assumption deserves closer attention. Recently, researchers working with Western populations have sought to clarify the relationships among depression, alcohol abuse and suicidality through an explicit investigation of their comorbidity. Using data collected at the Flathead Reservation, this paper explores the degree to which the investigation of the comorbidity of these three disorders can validly reveal the relevant contours of psychopathological distress in a cross-cultural setting. The data show that while the comorbidity of problem drinking and depression can sometimes indicate severe psychopathological distress, measured in this case by suicidality, comorbidity cannot account for another group at high risk for suicide. The discrepancy is explicable with reference to the cultural construction of depression, drinking and suicidality in relation to the creation, maintenance and disruption of social bonds, rather than in relation to an internal state of demoralization.     

Le binge drinking chez les jeunes

Binge drinking refers to an alcohol intake of at least 5 drinks on a single occasion and in a limited period of time (less than two hours). Most of the time, binge drinking occurs during weekend evenings. The only goal of the binge drinker is to get drunk, whatever quantity of alcohol is needed. This behavior usually begins around 12–13 years of age, and dramatically increases after high school, in the context of parties. The 18–25 age range represents almost half of binge drinking prevalence. Maintenance of this behavior after 25 could be a predictive factor of future alcohol dependence; about 50% of binge drinkers become dependent. Health care professionals have an important role to play, not only during routine visits, but particularly after an accident or suicide attempt. Adolescents should be routinely asked about their alcohol drinking behavior, in order to give them the opportunity to talk freely about their problems. Once problems are recognized, they should be referred to the appropriate forums. Parents should be involved in the therapeutic process whenever possible. Recent public awareness of the binge drinking problem has led to government action, together with prevention activities oriented towards the youth.     

Family perceptions of post-deployment healthcare needs of Iraq/Afghanistan military personnel

Nearly 40 000 service members returning from Iraq and Afghanistan have suffered traumatic injuries, with over 300 000 at risk for post-traumatic stress disorder (PTSD) or other psychiatric problems. These veterans face numerous post-deployment health concerns, sharing substantial burdens with their families. Although many rely upon community-based health care, little is known about how these individuals present at family medicine clinics for perceived medical and psychological issues. We surveyed 347 patients during visits at six clinics, and respondents reported whether they,a family member or a close acquaintance had been deployed since 2001. Patients identified traumatic military experiences, plus any attributable health or social problems. The mean patient age was 47.5 years, with 71% women and 55% Hispanic individuals. Nearly one-quarter reported family members serving overseas while 52% knew someone deployed. Significant events included nearby explosion (21%) or combat injury (9%), along with a variety of other incidents. Among the half of individuals perceiving significant health or social ramifications, the most prevalent consequences were PTSD, depression and alcohol abuse. Divorce or marital problems were noted by13%, while many reported employment, legal or other difficulties. This study offers insights into post-deployment needs of military personnel and subsequent problems reported by family members. A high prevalence of traumatic combat events translated into serious health needs, plus social disruptions for veterans and their loved ones. As the long-term problems disclosed by returning service personnel continue to ripple across community clinics and other health systems, effective treatment planning mandates coordinated attention from multiple providers and service organisations.     

Negative-pressure wound therapy in the military: lessons learned

The utilization of negative pressure for medicinal purposes dates back to 600 bc. The U.S. military has been engaged in continuous overseas combat operations since 2001. Negative-pressure wound therapy has been in use in the treatment of casualties from these operations since 2004. It represents a new standard of practice in combat wound care; it promotes granulation tissue formation and creates mechanical forces supporting wound contraction, facilitating definitive wound closure. This article describes (1) the use of negative-pressure wound therapy in combat casualty care, (2) inherent challenges of its use in theater of operations and across the echelons of care, (3) modifications of this wound therapy to meet military-specific needs, and (4) future directions with this novel wound care modality.     

Cell force microscopy on elastic layers of finite thickness

Forces applied by cells to substrates can be measured using soft substrates with embedded displacement markers. Traction forces are retrieved from microscopic images by determining the displacements of these markers and fitting the generating forces. Here we show that using elastic films of 5-10-microm thickness one can improve the spatial resolution of the technique. To this end we derived explicit equations for the mechanical response of an elastic layer of finite thickness to point forces. Moreover, these equations allow highly accurate force measurements on eukaryotic cells on films where finite thickness effects are relevant (below approximately 60 microm).     

北方军人消化性溃疡流行病学调查

目的：了解消化性溃疡（PU）在我军区部队中的发病情况以及相关危险因素,为进一步预防和治疗研究提供基础。方法：通过整群抽样的方法,运用统一的自填问卷,调查研究对象PU的发病情况和暴露因素以及其它影响因素。结果：军人PU相关症状发生率（Sc≥5）为8.41%（618/7345,95%CI=7.77%~9.03%）。多因素分析发现,兵龄、消化性溃疡的家族史、NSAID用药史、精神紧张、脾气易怒与PU症状积分（Sc≥5）发生率显著相关,其他因素（年龄、BMI、文化程度、出生地、吸烟、饮酒、刺激食物、饮食规律）与PU症状的发生率未见明显关系。结论：北方部队PU症状的发生率低于南方部队,兵龄、消化性溃疡的家族史、NSAID用药史、精神紧张、脾气易怒可能是军人消化性溃疡的危险因素。     

Psychological Distress in the Hospital Setting: A Comparison between Native Dutch and Immigrant Patients

BackgroundPrevalence of psychological distress (i.e. depressive and anxiety symptoms) in medically ill patients is high. Research in the general population shows a higher prevalence of psychological distress among immigrants compared to natives. Our aim was to examine the prevalence of psychological distress in the hospital setting comparing immigrant and native Dutch patients and first and second generation immigrant patients.MethodsPrevalence of psychological distress was assessed using the extended Kessler-10 (EK-10) in 904 patients in a Dutch general teaching hospital. Logistic regression was used to calculate odds ratios to determine differences between native and immigrant patients and first and second generation immigrants in the prevalence of psychological distress. We adjusted for demographic and social variables, socio-economic status, physical quality of life, history of psychiatric disease and health care use.ResultsOf 904 patients, 585 were native Dutch patients and 319 were immigrant patients. The prevalence of psychological distress in native compared to immigrant patients was 54% and 66% respectively, with especially high prevalences among Turkish and Moroccan immigrant patients. The crude OR for prevalence of psychological distress for immigrant patients versus native patients was 1.7 (95% CI 1.2–2.2) and for first versus second generation immigrant patients 2.1 (95% CI 1.2–3.5). After full adjustment ORs were 1.7 (95% CI 1.2–2.3) and 2.2 (95% CI 1.2–4.1) respectively.ConclusionImmigrant patients and first generation immigrant patients were more likely to have psychological distress compared to native patients and second generation immigrant patients respectively. We found a particularly high prevalence of psychological distress in Turkish and Moroccan immigrants.     

Diagnoses and factors associated with medical evacuation and return to duty among nonmilitary personnel participating in military operations in Iraq and Afghanistan

Background

Nonmilitary personnel play an increasingly critical role in modern wars. Stark differences exist between the demographic characteristics, training and missions of military and nonmilitary members. We examined the differences in types of injury and rates of returning to duty among nonmilitary and military personnel participating in military operations in Iraq and Afghanistan.

Methods

We collected data for nonmilitary personnel medically evacuated from military operations in Iraq and Afghanistan between 2004 and 2007. We compared injury categories and return-to-duty rates in this group with previously published data for military personnel and identified factors associated with return to duty.

Results

Of the 2155 medically evacuated nonmilitary personnel, 74.7% did not return to duty. War-related injuries in this group accounted for 25.6% of the evacuations, the most common causes being combat-related injuries (55.4%) and musculoskeletal/spinal injuries (22.9%). Among individuals with non–war-related injuries, musculoskeletal injuries accounted for 17.8% of evacuations. Diagnoses associated with the highest return-to-duty rates in the group of nonmilitary personnel were psychiatric diagnoses (15.6%) among those with war-related injuries and noncardiac chest or abdominal pain (44.0%) among those with non–war-related injuries. Compared with military personnel, nonmilitary personnel with war-related injuries were less likely to return to duty (4.4% v. 5.9%, p = 0.001) but more likely to return to duty after non–war-related injuries (32.5% v. 30.7%, p = 0.001).

Interpretation

Compared with military personnel, nonmilitary personnel were more likely to be evacuated with non–war-related injuries but more likely to return to duty after such injuries. For evacuations because of war-related injuries, this trend was reversed.In modern warfare, injuries sustained in combat have never been the leading source of attrition among soldiers. In World War I, World War II and the Korean War, respiratory and infectious diseases were the top reasons for hospital admissions among service members. By the Vietnam Conflict, non-battle injuries had supplanted respiratory illness as the leading cause of hospital admissions and have remained the leading cause ever since.^1,2The principal causes for medical evacuation of military personnel from US operations in Iraq and Afghanistan were recently described in a large four-year epidemiologic study.³ In descending order, the leading reasons were musculoskeletal conditions, combat-related injuries, neurologic symptoms and psychiatric disorders; the last category surpassed combat-related injuries as the number two reason in the latter half of both engagements. However, nonmilitary personnel were not included in that study. Over the past three years, nonmilitary members, including US Department of Defense civilians, private contractors and diplomats, have comprised about 50% of personnel serving in Iraq and about two-thirds of those serving in Afghanistan.^4,5Several reasons may explain why the types of injury and the return-to-duty rates differ between military and nonmilitary personnel. First, the motivations for overseas deployment might differ between the groups. Whereas some civilian personnel (e.g., diplomats) may be assigned to positions in Iraq and Afghanistan, virtually all private contractors volunteer for their jobs. In contrast, most military members have little choice in their deployment. Second, military and nonmilitary members assigned to war zones have different occupational specialties, living conditions and regulations to which they must adhere. Especially for junior military personnel, jobs tend to be more dangerous, living environments more austere and regulations more stringent. Finally, unlike military personnel, who are paid regardless of deployment status, most contractors’ pay is contingent upon continued employment in theatres of operation. In addition, nonmilitary personnel are generally compensated with higher salaries than service members in comparable occupational specialties.In civilian cohorts, many of these factors have been shown to influence return-to-work rates in a variety of contexts. Studies of the effect of financial compensation on work status after injury have generally shown a direct correlation between return-to-work rates and higher income levels.^6,7 Similar associations have also been found between return-to-work rates and job satisfaction and coping mechanisms, factors that may be influenced by work conditions and perceived control over one’s environment.^8–10The objectives of our study were threefold: to ascertain whether the reasons for medical evacuation from military operations differed between military and nonmilitary personnel; to determine whether return-to-duty rates differed between the two groups; and to identify factors that influence return-to-duty rates among nonmilitary members.     

Is There an Association between Traumatic Dental Injury and Social Capital,Binge Drinking and Socioeconomic Indicators among Schoolchildren?

ObjectivesTraumatic dental injury is defined as trauma caused by forces on a tooth with variable extent and severity. The aim of the present study was to investigate the prevalence of traumatic dental injury and its association with overjet, lip protection, sex, socioeconomic status, social capital and binge drinking among 12-year-old students.ResultsThe prevalence of traumatic dental injury was 29.9% (176/588). Traumatic dental injury was more prevalent among male adolescents (p = 0.010), those with overjet greater than 5 mm (p < 0.001) and those with inadequate lip protection (p < 0.001). In the multiple logistic regression analysis, overjet [OR = 3.80 (95% CI: 2.235–6.466), p < 0.0001], inadequate lip protection [OR = 5.585 (95% CI: 3.654–8.535), p < 0.0001] and binge drinking [OR = 1.93 (95% CI: 1.21–3.06), p = 0.005] remained significantly associated with traumatic dental injury.ConclusionsThe present findings suggest that a high level of total social capital and trust are not associated with TDI in adolescents, unlike binge drinking. The effects of social and behavioral factors on TDI are not well elucidated. Therefore, further research involving other populations and a longitudinal design is recommended.     

Follow up of New Zealand participants in British atmospheric nuclear weapons tests in the Pacific.

OBJECTIVE--To study the health of Royal New Zealand Navy personnel who participated in atmospheric nuclear weapons tests conducted by the United Kingdom at Malden Island and Christmas Island in 1957 and 1958. DESIGN--Blinded, controlled follow up of up to 30 years. SETTING--New Zealand. SUBJECTS--528 Men known to have participated in the tests and a control group of 1504 men who were in the Royal New Zealand Navy during the same period but did not participate in the tests. MAIN OUTCOME MEASURES--Mortality and incidence of cancer. RESULTS--Follow up for the period 1957-87 was 94% complete in test participants and 91% complete in the controls. There were 70 deaths among test participants and 179 deaths among controls, yielding a relative risk of 1.08 (90% confidence interval 0.85 to 1.38, p = 0.29). The relative risk of death from causes other than cancer was 0.96 (0.71 to 1.29, p = 0.59) whereas the relative risk of death from cancer was 1.38 (0.90 to 2.10, p = 0.09) and of the incidence of cancer was 1.12 (0.78 to 1.60, p = 0.29). For cancers other than haematological malignancies the relative risk was 1.14 (0.69 to 1.83, p = 0.31) for mortality and 1.01 (0.67 to 1.50, p = 0.48) for incidence. There were seven deaths from haematological cancers among test participants (relative risk 3.25, 90% confidence interval 1.12 to 9.64, p = 0.02), including four leukaemias (5.58, 1.04 to 41.6, p = 0.03). The relative risk for incidence of haematological cancers was 1.94 (0.74 to 4.84, p = 0.10) and that for leukaemia was 5.51 (1.03 to 41.1, p = 0.03). There were no cases of multiple myeloma in the test participants during the follow up period, but the expected number was only 0.3. CONCLUSIONS--Although the numbers are small, the findings for leukaemia are similar to those for British participants in the nuclear weapons test programme. Some leukaemias, and possibly some other haematological cancers, may have resulted from participation in this programme. There is little evidence of an increased risk for non-haematological cancers, and there is no evidence of an increased risk for causes of death other than cancer.     

Concurrent outbreak of norovirus genotype I and enterotoxigenic Escherichia coli on a U.S. Navy ship following a visit to Lima, Peru

An outbreak of norovirus (NoV) genotype I and Enterotoxigenic Escherichia coli (ETEC) occurred among US Navy Ship personnel following a visit to Lima, Peru, in June 2008. Visiting a specific area in Lima was significantly associated with illness. While ETEC and NoV are commonly recognized as causative agents of outbreaks, co-circulation of both pathogens has been rarely observed in shipboard outbreaks.