Defense Medical Epidemiology Database Research Articles

Risks for Enlisted Navy Divers Compared to Other Enlisted Sailors: An Examination of Illnesses That May Be Associated With Exposure to Contaminated Water Diving.

Illnesses among Navy divers degrade readiness, decrease manpower levels, and increase costs for medical care. Prior research has shown that Navy divers have high rates of the types of illnesses that might be because of diving in contaminated water. The objectives of this study were to examine medical records of U.S. Navy Sailors from 2016 to 2022 and determine if divers have higher incidence rates of health conditions that might be associated with contaminated water diving compared to non-divers. For this retrospective cohort study, we used data from the Defense Medical Epidemiology Database (DMED). The DMED is operated by the Armed Forces Health Surveillance Division and uses data from the Defense Manpower Data Center to classify occupations. The DMED provides free online access to a de-identified subset of data contained within the Defense Medical Surveillance System.The population was U.S. Navy enlisted males, aged 25 to 29 years. Divers were compared to non-divers using 8 selected diagnoses that may reasonably be associated with diving in contaminated water. During the study period, the database contained a total of 5,474 diver and 827,406 non-diver person-years. Of the 8 diagnoses, the ones with the largest number of cases for divers were upper respiratory infections with 128 and ear disorders with 62. The relative risks (RRs) for divers compared to non-divers were higher for otitis externa (RR = 1.44; confidence interval = 1.03, 2.01) and for ear disorders (RR = 1.15; confidence interval = 0.89, 1.47); for the other 6 diagnoses, the divers had lower rates than the non-divers. The high RRs found for otitis externa and ear disorders support the need to devote resources to better understand the reasons for these higher risks and to develop, test, and implement targeted risk-reduction strategies. Future studies should attempt to link verified contaminated water exposures with adverse health outcomes and calculate risks based on criteria such as age and dive factors.

Macrotraumatic Fractures of the Multisegmented Ankle-Foot Complex in Military Tactical Athletes: A Cohort Study.

Ankle-foot injuries are common in military personnel and substantially degrade function and force readiness. The purpose of this retrospective cohort study was to assess the incidence and contributing factors of traumatic ankle-foot fractures in the US military. A population-based study of all service members in the US military was performed assessing the factors of sex, occupation, service branch, rank, and year on segmental tibia-fibula, rearfoot, and forefoot fracture incidence between 2006 and 2015. The Defense Medical Epidemiology Database was queried for the number of individuals with fractures of the tibia-fibula, rearfoot, and forefoot using International Classification of Diseases, Ninth Revision, Clinical Modification on the initial medical encounter. Unadjusted relative risk (RR) calculations were performed assessing sex and occupation. A negative binomial regression assessed the adjusted factors of sex, branch, rank, and year. During this study, 95,540 enlisted service members (8.4 per 1,000 person-years) and 13,318 military officers (5.8 per 1,000 person-years) were diagnosed with ankle-foot fractures. In the adjusted analysis, sex was found to only be a significant factor in forefoot fractures (RR, 1.54), with female service members having a significantly higher risk. There were no significant sex-related differences observed in tibia-fibula or rearfoot fractures. US Navy and Air Force personnel had significantly lower risk of tibia-fibula fractures (RR range, 0.76-0.84) compared with the US Army. Forefoot fracture risk was significantly higher in the US Marine Corps (RR, 1.47) compared with the US Army. Officers had consistently lower risk for fractures in each segment (RR range, 0.68-0.77) compared with enlisted personnel. Enlisted engineers, aviation, and artillery/gunnery compared to infantry, and ground/naval gunfire officers had the greatest relative risk compared all other officer fields (RR range, 1.11-3.67). Sex, occupation, branch, and rank were salient factors for macrotraumatic ankle-foot fractures. These findings can be used to inform and increase precision in medical planning and in the targeted development of preventive interventions.

Incidence ofShoulder Labral Pathology inUnited States Military Members.

Shoulder injuries account for approximately 8% to 24% of all musculoskeletal injuries in the military. Recently, a change was made to service-specific physical fitness tests. Knowledge of relative shoulder labral injury rates before and after this change would help guide future directions and preventive strategies. However, we found no previous literature evaluating the rates of labral injury among United States Military branch personnel by enlistment status (enlisted versus officer), gender, age, or race. In this retrospective epidemiological study, we queried the Defense Medical Epidemiology Database for International Classification of Disease, Tenth Revision (ICD-10) code S43.43 (superior glenoid labrum lesion) to determine the total number of patients with a shoulder labral injury from 2016 to 2019. Results were assessed for demographic associations of shoulder labral injury with branch, service occupation, rank, gender, race, and age. Queries were limited to first-time occurrences and ambulatory data only. Overall, our study found the incidence of shoulder labral injuries to be largely conserved each year from 2016 to 2019 (3.22-3.35/1000/year). Incidence of labral injury was highest in males, White service members, the junior enlisted, the Army service branch, ages 20 to 29, and enlisted non-combat personnel. With knowledge of injury patterns in specific military populations, initiatives may be taken to identify at-risk service members with the goal of informing future preventive strategies.

Expanding Behavioral andOccupational Health Research inMilitary Police.

It is important to understand the behavioral and occupational health needs of military police personnel, a high-risk and understudied population. The incidence rates of behavioral and occupational conditions were examined from the years of 2005 to 2021 from the Defense Medical Epidemiology Database. Single-sample chi-square analyses were performed to analyze the differences in the incidence rates across demographic groups relative to population density. There were moderate-to-large increases in sleep-related disorders and mood or stress-related disorders. There were also patterns of overrepresentation or underrepresentation in diagnoses of various conditions by sex, age group, marital status, race, service branch, and pay grade. It is important to provide tailored resources and programming to employees in high-stress settings to help prevent or manage behavioral and occupational health conditions and reduce the stigma surrounding the utilization of such resources and programs.

Safety of mRNA Vaccines Administered During the First Twenty-Four Months of the International COVID-19 Vaccination Program

Two mRNA-based COVID vaccines were granted emergency use authorization in both children and adults in 2021 after a drastically accelerated approval process that allowed the manufacturers to essentially fast-track their vaccines. We analyzed data from regulatory surveillance and self-reporting systems like Defense Medical Epidemiology Database(DMED); EudraVigilance; Eurostat; German health insurers; the Israeli Minister of Health; the Natural Cycles app; Public Health Scotland; the United Kingdom’s (UK) Office for National Statistics (ONS); UK’s yellow card reporting system; the vaccine adverse event reporting system (VAERS); and v-safe entries to look for long-term adverse events of these vaccines that cannot be captured in the expedited clinical safety trials. In this observational study, we analyzed non-foreign VAERS data for selected symptoms reported after COVID, influenza, and pertussis vaccines and calculated rates per vaccine dose administered as well as proportion of total reports received. We also looked at DMED data and compared annual incidence rates of selected conditions by taking into account the total number of military personnel for each study year. Our data show, among other trends, increases in adverse event reports if we compare COVID vaccines to influenza and pertussis vaccines and statistically significant higher numbers of hospital encounters in military personnel, as well as increases in incidences of thromboembolic conditions, such as menstrual abnormalities, myocarditis, and cerebrovascular events after the implementation of COVID vaccine mandates, compared to the five years prior. We verified these observations using data from EudraVigilance; the UK’s ONS; German health providers; and Eurostat. Our meta-analysis of both national and international vaccine adverse events emphasizes the importance of re-evaluating public health policies that promote universal mass vaccination and multiple boosters for all demographic groups. In combination with anecdotal evidence, limitations of the safety trials, and the decreased lethality of new strains our research demonstrates that the cost (both monetary and humanitarian) of vaccinating otherwise healthy people, and especially children, may outweigh the benefits.

Opioid use disorder in the active service: Implications for intervention.

Military service members experience occupational-specific injuries that may result in chronic pain and comorbid behavioral health concerns. Data from the Defense Medical Epidemiology Database was used to examine opioid use disorder (OUD) diagnoses between 2016 and 2021. Statistical analysis calculated incidence rates and diagnostic variability by demographic density. The average incidence rate of OUD was 6.1 (per 10,000) and declined by 34% between 2016 and 2021. Diagnoses were most frequently made in service members classified as male, married, white, aged 30-39, junior enlisted, and serving in the Army. To our knowledge, this is the first study to examine the incidence rates of OUD among active duty personnel.

Nightmare disorder in active-duty US military personnel

Study objectivesMilitary personnel experience high rates of traumatic experiences. Despite this, few studies have examined the presence of nightmare disorder in military personnel. The primary aim of this study was to examine diagnoses of nightmare disorder across the 4 largest branches of the active-duty US military. Design & participantsData and service branch densities used to derive the expected rates of diagnoses of nightmare disorder were drawn from the Defense Medical Epidemiology Database. The branches examined included all active-duty services members in the US Army, Navy, Marine Corps, and Air Force, who served between 2016 and 2021. Single-sample chi-square goodness of fit tests were conducted to examine within-variable differences for military relevant variables. ResultsBetween 2016 and 2019, the incidence rates of nightmare disorder (per 10,000 service members) in the US Department of Defense ranged from 11.3 in 2016 to a low of 6.9 in 2018. Service members who were classified as non-white, female, over the age of 35, married, in the Army, and/or a noncommissioned officer, were diagnosed at greater rates relative to their representation in the military population (p < .001). ConclusionOur findings of higher than expected rates of nightmare disorder in older, senior service members as well as those in the Army align with the known precipitant of nightmares, and trauma. However, the reason for the finding that female and Black service members have higher than expected rates is not readily apparent.

Incidence rates of emotional, sexual, and physical abuse in active-duty military service members, 1997–2015

Sexual, emotional, and physical abuse are often underreported in the Military, and large-scale epidemiological research is limited. The current work examines the incidence rates of abuse across six demographic factors (age, gender, rank, marital status, race, and branch) using the Defense Medical Epidemiology Database (DMED) in active-duty U.S. military service members to establish a comparative cohort for future work in this area. Data were extracted from 1997 to 2015 and analyzed using a one-sample chi-square goodness-of-fit test. Women report emotional abuse over two times more than expected, physical abuse twice as much, and sexual abuse five times more than expected. Black service members were reported emotional abuse at rates 87% greater than anticipated based on base military proportions, reported double the amount of physical abuse than expected, and received sexual abuse diagnoses 35% more than expected. Paygrades E5-E9 had higher than expected emotional abuse rates, while married service members had higher than expected emotional and physical abuse rates. White, male, and higher rank service members reported lower than expected rates for any abuse type. The present study provides a strong foundation for further research and developing interventions aimed toward vulnerable populations in the U.S. military.

Sex, military occupation and rank are associated with risk of anterior cruciate ligament injury in tactical-athletes

IntroductionAnterior cruciate ligament (ACL) injury is common within the US military and represents a significant loss to readiness. Since recent changes to operational tempo, there has not been an analysis...

Sex Differences in the Incidence and Risk of Ankle–Foot Complex Stress Fractures Among U.S. Military Personnel

Background: The objective of this study was to evaluate sex differences in the incidence and risk of ankle-foot complex (AFC) stress fractures among U.S. military personnel, which could assist in developing management strategies as females assume a greater role in U.S. military operations. Materials and Methods: The Defense Medical Epidemiology Database was used to identify all diagnosed AFC stress fractures in military personnel from 2006 to 2015. Cumulative incidence of AFC stress fractures was calculated and compared by year, service branch, and military rank. Sex differences in the risk of AFC stress fractures by occupation were examined, and integrated (i.e., male and female) occupations were compared with nonintegrated (i.e., male only) occupations. Results: A total of 43,990 AFC stress fractures were identified. The overall incidence rate was 2.76 per 1,000 person-years (p-y) for males and 5.78 per 1,000 p-y for females. Females consistently had higher incidence of AFC stress fractures across all subgroups, particularly among enlisted personnel. Female enlisted service members had the highest risk of AFC stress fractures in aviation (relative risk [RR] = 5.74; 95% confidence interval [CI]: 4.80-6.87) and artillery/gunnery (RR = 5.15; 95% CI: 4.62-5.75) occupations. Females in integrated occupations had significantly higher rates of AFC stress fractures than males in both integrated and nonintegrated occupations (i.e., special forces, infantry, and mechanized/armor). Conclusions: Females in the U.S. military have a higher risk of AFC stress fractures than males. As integration of females into previously sex-restricted occupations continues, focused prevention efforts may be needed to reduce injury burden and maximize medical readiness.

Behavioral and Occupational Health in Military Firefighters: An Understudied Population.

To our knowledge, no studies on health conditions in U.S. military firefighters exist. Data and demographics from the Defense Medical Epidemiology Database were analyzed on several shared medical issues among military personnel and civilian firefighters. Descriptive statistics and Chi-Square goodness of fit tests were conducted to support study aims. Between 2001 and 2015, substantial incidence rate increases (per 10,000) of tinnitus, PTSD, insomnia, and OSA (2005-2015) were observed. Modest to large increases in depressive disorders, adjustment reaction, generalized anxiety disorder, and panic disorder were observed. Decreasing rates were observed for alcohol dependence, hypertension, and tobacco use disorder. While efforts have examined the impact of sustained operations on military members, first responder military subgroups like firefighters are deficient. Cognitive Behavior Therapy interventions are efficacious for preventing and reducing behavioral health problems; therefore, tailoring them specifically for U.S. military firefighters could significantly improve quality of life and long-term health.

Alcohol use disorder in active duty service members: Incidence rates over a 19-year period

Background: Alcohol use is a concerning issue for the military given its potential negative impact on human performance. Limited data are available regarding the incidence of alcohol use disorder in the military, which is critical to understand to evaluate force readiness, as well as for preventative initiatives and treatment planning. The aim was to examine the alcohol use disorder incidence rates (overall and across demographics) among active duty service members from 2001 to 2018. Methods: Data on 208,870 active duty service members between 2001 and 2018 from the Defense Medical Epidemiology Database was examined. Incidence rates were analyzed to determine the diagnostic rates of AUD (including both alcohol abuse and dependence), which were then examined by sex, age, service branch, military pay grade, marital status, and race. Results: Incidence rates of AUD in active duty service members (per 1,000 service members) ranged from 6.45 to 10.50 for alcohol abuse and 5.21 to 7.11 for alcohol dependence. Initial diagnoses of new-onset AUD occurred most frequently within 20–24 year-old, white, male, and non-married U.S. Army service members in the enlisted pay grades of E-1 to E-4. Statistically significant differences (p <.001) were found between observed and expected counts across all examined demographic variables. Conclusions: To our knowledge, this is the first study to provide a comprehensive examination of AUD incidence rates in an active-duty military population over an extended 18-year period and during the last decade. Incidence rates were higher than expected for alcohol dependence and lower than expected for alcohol abuse. Given the untoward effects of AUD on overall health and force readiness, active-duty service members may benefit from more advanced preventative interventions to decrease incidence rates of AUD over time. Future research should use these data to develop targeted interventions for the demographics at greatest risk.

Anterior Knee Pain Risk in Male and Female Military Tactical Athletes.

Anterior knee pain (AKP) is ubiquitous in early career military members and exacerbated during functional tasks required during military duties. Therefore, it is important to understand the risk of this condition among male and female tactical athletes in diverse military occupations. To assess sex and occupation with respect to the AKP risk in military members. Descriptive epidemiology study. United States Armed Forces. All military members diagnosed with anteropatellar or retropatellar pain, patellar instability, or knee tendinopathy on their initial encounter from 2006 to 2015. The Defense Medical Epidemiology Database was queried for the number of individuals with AKP. Relative risk (RR) and χ2 statistics were calculated in the assessment of sex and occupational category. Regressions were calculated to determine associations between service branch, sex, and AKP across time. From 2006 to 2015, a total of 151 263 enlisted and 14 335 officer service members were diagnosed with AKP. Enlisted females had an incidence rate of 16.7 per 1000 person-years compared with enlisted males' incidence rate of 12.7 per 1000 person-years (RR = 1.32; 95% CI = 1.30, 1.34; P < .001) across all AKP diagnoses. Female officers had an incidence rate of 10.7 per 1000 person-years; male officers had an incidence rate of 5.3 per 1000 person-years (RR = 2.01; 95% CI = 1.94, 2.09). Differences in risk were also noted across military occupations for both enlisted and officer service members (P values < .05). Sex and military occupation were salient factors for the AKP risk. Evaluating training requirements and developing intervention programs across military occupations could serve as a focus for future research aiming to decrease the incidence of chronic knee pain.

Sex and occupation are salient factors associated with lateral ankle sprain risk in military tactical athletes

ObjectivesTo assess the risk of lateral ankle sprain (LAS) in male and female tactical athletes across different military occupations in the US military. DesignRetrospective cohort. MethodsThe Defense Medical Epidemiology Database was queried for the number of individuals with ICD-9 diagnosis codes 845.00 (sprain of ankle, unspecified) and 845.02 (calcaneofibular ligament sprain) on their initial encounter from 2006 to 2015. Relative risk (RR) and chi-square statistics were calculated assessing sex and occupational category on LAS risk. Results272,970 enlisted males (27.9 per 1000 person-years), 56,732 enlisted females (34.5 per 1000 person-years), 24,534 male officers (12.6 per 1000 person-years), and 6020 female officers (16.4 per 1000 person-years) incurred a LAS. Enlisted females in all occupational groups were at significantly higher risk for LAS than their male counterparts (RR 1.09–1.68; p<0.001), except for Engineers (p=0.15). Female officers had consistently higher risk for LAS in all occupational groups (RR 1.10–1.42; p<0.001) compared with male officers, except Ground/Naval Gunfire (p=0.23). Contrasted with Infantry, enlisted tactical athletes in the Special Operations Forces, Mechanized/Armor, Aviation, Maintenance, and Maritime/Naval Specialties were at lower risk (RR 0.38−0.93; p<0.001), Artillery, Engineers, and Logistics Specialties were at higher risk (RR 1.04–1.18; p<0.001), and Administration, Intelligence, and Communications were no different (p=0.69). Compared with Ground/Naval Gunfire officers, Aviation officers were at significantly lower risk (RR, 0.75; p<0.001), and Engineers, Maintenance, Administration, Operations/Intelligence, and Logistics officers were at higher risk (RR, 1.08–1.20; p<0.001). ConclusionsSex and military occupation were salient factors associated with LAS risk.

Incidence of insomnia and obstructive sleep apnea in active duty United States military service members.

Epidemiologic studies of obstructive sleep apnea (OSA) and insomnia in the U.S. military are limited. The primary aim of this study was to report and compare OSA and insomnia diagnoses in active duty the United States military service members. Data and service branch densities used to derive the expected rates of diagnoses on insomnia and OSA were drawn from the Defense Medical Epidemiology Database. Single sample chi-square goodness of fit tests and independent samples t-tests were conducted to address the aims of the study. Between 2005 and 2019, incidence rates of OSA and insomnia increased from 11 to 333 and 6 to 272 (per 10,000), respectively. Service members in the Air Force, Navy, and Marines were diagnosed with insomnia and OSA below expected rates, while those in the Army had higher than expected rates (p < .001). Female service members were underdiagnosed in both disorders (p < .001). Comparison of diagnoses following the transition from ICD 9 to 10 codes revealed significant differences in the amounts of OSA diagnoses only (p < .05). Since 2005, incidence rates of OSA and insomnia have markedly increased across all branches of the U.S. military. Despite similar requirements for overall physical and mental health and resilience, service members in the Army had higher rates of insomnia and OSA. This unexpected finding may relate to inherent differences in the branches of the military or the role of the Army in combat operations. Future studies utilizing military-specific data and directed interventions are required to reverse this negative trend.

Incidence (2008-2015) of post-traumatic headaches in United States military personnel

ABSTRACT Objective: To conduct a descriptive transversal study to evaluate the incidence and demographic characteristics of post-traumatic headache using data from the Defense Medical Epidemiology Database. Methods: A retrospective cohort study was conducted of data from 2008 to 2015 based on the International Classification of Diseases codes for both acute and chronic post-traumatic headache. Results: A total of 17,010 new cases of post-traumatic headaches were diagnosed among active duty military personnel. Reported incidence rates of post-traumatic headaches in the military increased 29-fold over the timeframe analyzed. Males enlisted in the Army were more likely to be diagnosed with post-traumatic headaches than females (O/E = 0.76), other branches, and officers. Conclusion: Findings of this study indicate that there is a significant incidence of post-traumatic headaches in the U.S. military. However, the incidence rates of post-traumatic headaches in the military are much lower than what was expected considering the number of traumatic brain injuries in the United States military reported by the Department of Defense for the same period. Additional research is needed to further evaluate these differences and the impact of PTHs on military personnel.

Incidence of Posterior Shoulder Instability in the United States Military: Demographic Considerations From a High-Risk Population

Background: Relatively little is known about the true incidence of posterior shoulder instability in the United States. Purpose/Hypothesis: The purpose of this study was to characterize the incidence of posterior shoulder instability in the US military population and to examine which characteristics place these patients at highest risk. We hypothesized that the rate of posterior instability in this cohort of patients would be higher than previously reported. Study Design: Descriptive epidemiology study. Methods: All initial cases of posterior shoulder dislocation and subluxation in the Defense Medical Epidemiology Database were screened between 2016 and 2018 using the relevant International Classification of Diseases–Tenth Revision-Clinical Modification codes. Incidences were calculated, and multivariate Poisson regression was used to calculate adjusted rate ratios for the effects of sex, race, age, military service branch, rank, and year. Results: The overall unadjusted incidence was 0.032 per 1000 person-years for posterior dislocations, 0.064 per 1000 person-years for posterior subluxations, and 0.096 per 1000 person-years for all cases of posterior shoulder instability. The total incidence of all shoulder instability was 1.84 per 1000 person-years, with posterior shoulder instability accounting for 5.2% of total cases. For posterior subluxation, significant differences between groups were found in the unadjusted and adjusted rate ratio (ARR) for sex (ARR, 3.31; 95% CI, 1.85-5.93 for men), race (ARR, 0.458; 95% CI, 0.294-0.714 for Black servicemembers and ARR, 0.632; 95% CI, 0.421-0.948 for servicemembers of other race), age (ARR, 3.69; 95% CI, 1.56-8.70 for patients aged 30-34 years), and military service branch (ARR, 0.663; 95% CI, 0.460-0.955 for Air Force servicemembers). For posterior shoulder dislocations, a significant difference was found only between men and women (ARR, 4.55; 95% CI, 1.85-11.2 for men). Conclusion: The incidence of posterior shoulder instability among US military personnel is higher than previously reported in the general US population, with a majority of cases due to subluxation. This increased incidence is likely reflective of a young and highly active population along with improvements in awareness and diagnosis of posterior instability in recent years.

Incidence of Pelvic Ring Fractures in the U.S. Military Population.

Introduction Pelvic ring fractures occur frequently among the elderly population, but some studies demonstrate a bimodal distribution where the incidence is elevated among younger age groups as well. The mechanisms of injury also vary based on age groups. Previous studies are specific to trauma registries and centers, but epidemiological data within the U.S. military are sparse. In the U.S. military population, pelvic ring fractures can be related to high-energy trauma including motor vehicle accidents and combat warfare. The purpose of this study was to determine the incidence of pelvic ring fractures among active duty U.S. military service members between 2006 and 2015, while also describing the demographics associated with the findings.Materials and MethodsAll data were collected from the U.S. Defense Medical Epidemiology Database (DMED). To calculate the incidence rates, only first-time occurrences for pelvic ring fractures among military members were used. Each point was identified using International Classification of Diseases, Ninth Revision (ICD-9), clinical modification code 808 for “fractures of the pelvis.” A multivariate Poisson regression analysis was used to estimate the incidence rate per 1,000 person-years and 95% confidence intervals while controlling for sex, race, age, rank, and service. Rate ratios were calculated using different referent factors based on differences in sex, race, age, rank, and service branch. This study was IRB exempt as all the data used were de-identified patient data from the DMED system.ResultsOver the 10-year study period, a total of 4,802 incident cases of pelvic ring fractures, and a total of 13,748,429 person-years were documented. The overall incidence rate of pelvic ring fractures was 0.35 per 1,000 person-years. The incidence of pelvic ring fractures was highest among the youngest age group (<20 years) and among the lower-ranking service members. Additionally, other demographic groups such as the White race, female sex, and Army service members showed the highest incidence rates.ConclusionOur study determined baseline epidemiological data on incidence rates of pelvic ring fractures in the U.S. military. Patient demographics may be contributing factors, and the present analysis was able to elucidate associated underlying demographics. We demonstrated that the incidence was highest among the younger age groups, and that incidence rates may be specific to age cohorts. This study also found that lower-ranking service members had the highest incidence in all service branches, suggesting a form of occupational risk. Furthermore, our findings suggest that females, White race groups, and Army enlisted service members show a significantly higher incidence rate and may be at a greater risk. Our findings are important as they broaden the understanding of the patterns of pelvic ring fractures in the U.S. military population and occupational risks associated with this population.

Severe Upper Limb Injuries in U.S. Military Personnel: Incidence, Risk Factor and Outcomes.

Severe upper limb injuries (SULI) may pose a significant public health challenge for the military; however, SULI has not been previously defined or studied in the US military. Objective: Determine SULI incidence, risk factors, and outcomes. Active Component (AC) U.S. military personnel who served during January 1, 2003 to December 31, 2012 who met the case definition for SULI (N = 213,745) and a random sample from the same population without SULI were included. Data from the Defense Medical Surveillance System and Defense Medical Epidemiology Database was used to calculate incidence. Multiple logistic regression and Cox proportional hazards models were used to analyze SULI risk factors and attrition. SULI incidence was 15/1,000 person-years. Higher SULI risk was observed in men (OR 1.25; 95% CI 1.22-1.27), age 25-29 (OR 1.07; 95% CI 1.05-1.09) compared to age 20-24, E5-E9 (OR 1.14; 95% CI 1.12-1.17) compared to E1-E4, serving in Coast guard (OR 1.62; 95% CI 1.56-1.68) and Air Force (OR 1.17; 95% CI 1.14-1.19) relative to Army and with a deployment history (OR 2.16, 95% CI 2.12-2.19) while SULI risk was lower for blacks (OR 0.91; 95% CI 0.90-0.93) and those in the "other race" category (HR 0.81; 95% CI 0.80-0.84) compared to whites. SULI was associated with 23% increased risk of attrition (HR 1.23; 95% CI 1.22-1.24). The study findings provide preliminary evidence on the incidence, natural history and distribution of SULI in this population. The findings indicate SULI may impact readiness and result in premature military separation.

Non-modifiable Risk Factors Associated with Avascular Necrosis in the US Military.

Often referred to as aseptic or osteonecrosis, avascular necrosis (AVN) typically affects people between 30 and 50 years of age. Given the substantial morbidity associated with AVN as well as overlapping age groups of both the military and average age at diagnosis for AVN, the military represents an ideal cohort for a large database study to elicit the incidence and epidemiology of AVN. The purpose of this study was to identify demographic risk factors in the United States military. First-time occurrences for ICD-9-CM codes for all types of AVN (head of humerus, head and neck of femur, medial femoral condyle, talus, and other bone) between 2004 and 2014 were queried in the Defense Medical Epidemiology Database. Multivariate data analysis was performed to obtain adjusted rate (adjusted for age, sex, race, rank, and branch of service). Between 2005 and 2014, 2,671 cases of AVN occurred among an at-risk population of 13,820,906 servicemembers for an unadjusted IR of 0.19 per 1,000 person-years. The most common location was located at the proximal femur, responsible for 41.7% of all cases. With an adjusted rate ratio of 18.7, the over 40 age-group accounted for 53.3% of cases. Servicemembers of black race, Senior rank, and the Army branch of service were more at risk for AVN. The overall incidence of AVN was 0.19 per 1,000 person-years. Whilte increasing age had the greatest influence on the development of symptomatic AVN, other statistically significant risk factors were found to be increasing age, black race, senior enlisted rank, and Army branch of service.