Paul J. Amoroso

Alcohol Use and Alcohol-Related Problems Before and After Military Combat Deployment

CONTEXT High rates of alcohol misuse after deployment have been reported among personnel returning from past conflicts, yet investigations of alcohol misuse after return from the current wars in Iraq and Afghanistan are lacking. OBJECTIVES To determine whether deployment with combat exposures was associated with new-onset or continued alcohol consumption, binge drinking, and alcohol-related problems. DESIGN, SETTING, AND PARTICIPANTS Data were from Millennium Cohort Study participants who completed both a baseline (July 2001 to June 2003; n=77,047) and follow-up (June 2004 to February 2006; n=55,021) questionnaire (follow-up response rate = 71.4%). After we applied exclusion criteria, our analyses included 48,481 participants (active duty, n = 26,613; Reserve or National Guard, n = 21,868). Of these, 5510 deployed with combat exposures, 5661 deployed without combat exposures, and 37 310 did not deploy. MAIN OUTCOME MEASURES New-onset and continued heavy weekly drinking, binge drinking, and alcohol-related problems at follow-up. RESULTS Baseline prevalence of heavy weekly drinking, binge drinking, and alcohol-related problems among Reserve or National Guard personnel who deployed with combat exposures was 9.0%, 53.6%, and 15.2%, respectively; follow-up prevalence was 12.5%, 53.0%, and 11.9%, respectively; and new-onset rates were 8.8%, 25.6%, and 7.1%, respectively. Among active-duty personnel, new-onset rates were 6.0%, 26.6%, and 4.8%, respectively. Reserve and National Guard personnel who deployed and reported combat exposures were significantly more likely to experience new-onset heavy weekly drinking (odds ratio [OR], 1.63; 95% confidence interval [CI], 1.36-1.96), binge drinking (OR, 1.46; 95% CI, 1.24-1.71), and alcohol-related problems (OR, 1.63; 95% CI, 1.33-2.01) compared with nondeployed personnel. The youngest members of the cohort were at highest risk for all alcohol-related outcomes. CONCLUSION Reserve and National Guard personnel and younger service members who deploy with reported combat exposures are at increased risk of new-onset heavy weekly drinking, binge drinking, and alcohol-related problems.

High injury rates among female army trainees: a function of gender?

BACKGROUND Studies suggest that women are at greater risk than men for sports and training injuries. This study investigated the association between gender and risk of exercise-related injuries among Army basic trainees while controlling for physical fitness and demographics. METHODS Eight hundred and sixty-one trainees were followed during their 8-week basic training course. Demographic characteristics, body composition, and physical fitness were measured at the beginning of training. Physical fitness measures were taken again at the end of training. Multivariate logistic regression analysis was used to evaluate the association between gender and risk of injury while controlling for potential confounders. RESULTS Women experienced twice as many injuries as men (relative risk [RR] = 2.1, 1.78-2.5) and experienced serious time-loss injuries almost 2.5 times more often than men (RR = 2.4, 1. 92-3.05). Women entered training at significantly lower levels of physical fitness than men, but made much greater improvements in fitness over the training period.In multivariate analyses, where demographics, body composition, and initial physical fitness were controlled, female gender was no longer a significant predictor of injuries (RR = 1.14, 0.48-2.72). Physical fitness, particularly aerobic fitness, remained significant. CONCLUSIONS The key risk factor for training injuries appears to be physical fitness, particularly cardiovascular fitness. The significant improvement in endurance attained by women suggests that women enter training less physically fit relative to their own fitness potential, as well as to men. Remedial training for less fit soldiers is likely to reduce injuries and decrease the gender differential in risk of injuries.

The Effect of Anterior Cruciate Ligament Reconstruction on the Risk of Knee Reinjury

Background Although there is evidence that very active, young patients are better served with anterior cruciate ligament reconstruction, there is a lack of objective data demonstrating that future knee injury is prevented by these procedures. Hypothesis Anterior cruciate ligament reconstruction protects against reinjury of the knee that would require reoperation. Study Design Retrospective cohort study. Methods A cohort of 6576 active-duty army personnel who had been hospitalized for anterior cruciate ligament injury from 1990 to 1996 were identified. Using the Total Army Injury and Health Outcomes Database, the authors followed these individuals for up to 9 years and collected clinical, demographic, and occupational data. These data were evaluated with bivariate and multivariable analyses to determine the effect of anterior cruciate ligament reconstruction on the rate of knee reinjury that required operation. Results Of the 6576 study subjects, 3795 subjects (58%) underwent anterior cruciate ligament reconstruction and 2781 (42%) did not. The rate of reoperation was significantly lower among the anterior cruciate ligament reconstruction group (4.90/100 person-years) compared with those treated conservatively (13.86/100 person-years; P < .0001). Proportional hazard regression analyses adjusted for age, race, sex, marital status, education, and physical activity level confirmed that anterior cruciate ligament reconstruction was protective against meniscal and cartilage reinjury (P < .0001). Secondary medial meniscal injury was more common than secondary lateral meniscal injury (P < .003). Younger age was the strongest predictor of failure of conservative management leading to late anterior cruciate ligament reconstruction (P < .0001). Conclusions Anterior cruciate ligament reconstruction protected against reoperation in this young, active population; younger subjects were more likely to require late anterior cruciate ligament reconstruction. Clinical Relevance Strong consideration should be given to anterior cruciate ligament reconstruction after anterior cruciate ligament injury in young, active individuals.

Risk of Diabetes in U.S. Military Service Members in Relation to Combat Deployment and Mental Health

OBJECTIVE Few prospective data exist on the risk of diabetes in individuals serving in the U.S. military. The objectives of this study were to determine whether military deployment, combat exposures, and mental health conditions were related to the risk of newly reported diabetes over 3 years. RESEARCH DESIGN AND METHODS Data were from Millennium Cohort Study participants who completed baseline (July 2001–June 2003) and follow-up (June 2004–February 2006) questionnaires (follow-up response rate = 71.4%). After exclusion criteria were applied, adjusted analyses included 44,754 participants (median age 36 years, range 18–68 years). Survey instruments collected demographics, height, weight, lifestyle, military service, clinician-diagnosed diabetes, and other physical and mental health conditions. Deployment was defined by U.S. Department of Defense databases, and combat exposure was assessed by self-report at follow-up. Odds of newly reported diabetes were estimated using logistic regression analysis. RESULTS Occurrence of diabetes during follow-up was 3 per 1,000 person-years. Individuals reporting diabetes at follow-up were significantly older, had greater baseline BMI, and were less likely to be Caucasian. After adjustment for age, sex, BMI, education, race/ethnicity, military service characteristics, and mental health conditions, only baseline posttraumatic stress disorder (PTSD) was significantly associated with risk of diabetes (odds ratio 2.07 [95% CI 1.31–3.29]). Deployments since September 2001 were not significantly related to higher diabetes risk, with or without combat exposure. CONCLUSIONS In this military cohort, PTSD symptoms at baseline but not other mental health symptoms or military deployment experience were significantly associated with future risk of self-reported diabetes.

Association of Time Since Deployment, Combat Intensity, and Posttraumatic Stress Symptoms With Neuropsychological Outcomes Following Iraq War Deployment

CONTEXT Previous research has demonstrated neuropsychological changes following Iraq deployment. It is unknown whether these changes endure without subsequent war-zone exposure or chronic stress symptoms. OBJECTIVE To determine the associations of time since deployment, combat intensity, and posttraumatic stress disorder (PTSD) and depression symptoms with longer-term neuropsychological outcomes in war-deployed soldiers. DESIGN Prospective cohort study involving (1) soldiers assessed at baseline (median, 42 days prior to deployment) and following return from Iraq (median, 404 days after return and 885 days since baseline), and (2) soldiers more recently returned from deployment assessed at baseline (median, 378 days prior to deployment) and following return from Iraq (median, 122 days after return and 854 days since baseline assessment). SETTING Active-duty military installations. PARTICIPANTS Two hundred sixty-eight male and female regular active-duty soldiers (164 with 1-year follow-up; 104 recently returned). MAIN OUTCOME MEASURES Neuropsychological performances (verbal learning, visual memory, attention, and reaction time). RESULTS There was a significant interaction between time and PTSD symptom severity (B= -0.01 [unstandardized], P = .04). Greater PTSD symptoms were associated with poorer attention in soldiers tested at 1-year follow-up (B = 0.01, P = .03) but not in recently returned soldiers. At 1-year follow-up, mean adjusted attention error scores increased by 0.10 points for every 10 points on the PTSD scale. Greater combat intensity was associated with more efficient postdeployment reaction-time performances, regardless of time since deployment (B = 0.48, P = .004), with mean adjusted reaction efficiency scores increasing by 4.8 points for every 10 points on the combat experiences scale. Neither depression nor contextual variables (alcohol use and deployment head injury) were significantly related to neuropsychological outcomes. CONCLUSIONS In this study of army soldiers deployed to the Iraq war, only PTSD symptoms (among soldiers back from deployment for 1 year) were associated with a neuropsychological deficit (reduced attention). Greater combat intensity was associated with enhanced reaction time, irrespective of time since return.

Self-reported risk-taking behaviors and hospitalization for motor vehicle injury among active duty army personnel

BACKGROUND Motor vehicle crashes are a leading cause of injury in the Army. Behaviors increasing risk for motor vehicle crashes are also prevalent, but research has not linked these behaviors directly to injury outcomes (e.g., hospitalizations). METHODS To evaluate the relationship between behavior and motor vehicle crash injuries, 99, 981 Army personnel who completed Health Risk Appraisal surveys in 1992 were followed for up to 6 years. Cox proportional hazards modeling was used to evaluate speeding, seat belt use, drinking patterns, and demographics. RESULTS A total of 429 soldiers were hospitalized for motor vehicle injury. Unadjusted analyses revealed that heavy drinking, drinking and driving, speeding, low seat belt use, younger age, minority race/ethnicity, and enlisted rank were significantly associated with motor vehicle injury, but neither smoking nor gender was. Multivariate models showed a significant trend of increasing injury risk with younger ages. Soldiers under age 21 were injured almost five times more often than those over age 40 (HR 4.89, 2.56-9.33). Also associated with risk for hospitalizations were minority race (HR 1.78, 1.46-2.18), heaviest drinkers versus abstainers (HR 1.81, 1.11-2.94), and seat belt use of 50% or less versus 100% (HR 1.40, 1.07-1.85). Although nonsignificant, there was evidence of an age-drinking interaction where the difference in injury risk between those older and those younger than 21 was greatest at low alcohol consumption levels. CONCLUSIONS Modifiable risk factors associated with motor vehicle injuries include heavy drinking and low seat belt use. Programs targeting these behaviors that meet the needs of young and minority soldiers are needed. The high density of young, at-risk soldiers residing in base housing may provide a unique opportunity for a residential intervention program.

Assessing nonresponse bias at follow-up in a large prospective cohort of relatively young and mobile military service members

BackgroundNonresponse bias in a longitudinal study could affect the magnitude and direction of measures of association. We identified sociodemographic, behavioral, military, and health-related predictors of response to the first follow-up questionnaire in a large military cohort and assessed the extent to which nonresponse biased measures of association.MethodsData are from the baseline and first follow-up survey of the Millennium Cohort Study. Seventy-six thousand, seven hundred and seventy-five eligible individuals completed the baseline survey and were presumed alive at the time of follow-up; of these, 54,960 (71.6%) completed the first follow-up survey. Logistic regression models were used to calculate inverse probability weights using propensity scores.ResultsCharacteristics associated with a greater probability of response included female gender, older age, higher education level, officer rank, active-duty status, and a self-reported history of military exposures. Ever smokers, those with a history of chronic alcohol consumption or a major depressive disorder, and those separated from the military at follow-up had a lower probability of response. Nonresponse to the follow-up questionnaire did not result in appreciable bias; bias was greatest in subgroups with small numbers.ConclusionsThese findings suggest that prospective analyses from this cohort are not substantially biased by non-response at the first follow-up assessment.

Disordered Eating and Weight Changes After Deployment: Longitudinal Assessment of a Large US Military Cohort

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

Using narrative text and coded data to develop hazard scenarios for occupational injury interventions.

Objective: To determine whether narrative text in safety reports contains sufficient information regarding contributing factors and precipitating mechanisms to prioritize occupational back injury prevention strategies. Design, setting, subjects, and main outcome measures: Nine essential data elements were identified in narratives and coded sections of safety reports for each of 94 cases of back injuries to United States Army truck drivers reported to the United States Army Safety Center between 1987 and 1997. The essential elements of each case were used to reconstruct standardized event sequences. A taxonomy of the event sequences was then developed to identify common hazard scenarios and opportunities for primary interventions. Results: Coded data typically only identified five data elements (broad activity, task, event/exposure, nature of injury, and outcomes) while narratives provided additional elements (contributing factor, precipitating mechanism, primary source) essential for developing our taxonomy. Three hazard scenarios were associated with back injuries among Army truck drivers accounting for 83% of cases: struck by/against events during motor vehicle crashes; falls resulting from slips/trips or loss of balance; and overexertion from lifting activities. Conclusions: Coded data from safety investigations lacked sufficient information to thoroughly characterize the injury event. However, the combination of existing narrative text (similar to that collected by many injury surveillance systems) and coded data enabled us to develop a more complete taxonomy of injury event characteristics and identify common hazard scenarios. This study demonstrates that narrative text can provide the additional information on contributing factors and precipitating mechanisms needed to target prevention strategies.

Prior health care utilization as a potential determinant of enrollment in a 21-year prospective study, the Millennium Cohort Study

Results obtained from self-reported health data may be biased if those being surveyed respond differently based on health status. This study was conducted to investigate if health, as measured by health care use preceding invitation, influenced response to invitation to a 21-year prospective study, the Millennium Cohort Study. Inpatient and outpatient diagnoses were identified among more than 68,000 people during a one-year period prior to invitation to enroll. Multivariable logistic regression defined how diagnoses were associated with response. Days spent hospitalized or in outpatient care were also compared between responders and nonresponders. Adjusted odds of response to the questionnaire were similar over a diverse range of inpatient and outpatient diagnostic categories during the year prior to enrollment. The number of days hospitalized or accessing outpatient care was very similar between responders and nonresponders. Study findings demonstrate that, although there are some small differences between responders and nonresponders, prior health care use did not affect response to the Millennium Cohort Study, and it is unlikely that future study findings will be biased by differential response due to health status prior to enrollment invitation.