United States Army Medical Command

BACKGROUND: Clinical predictors of advanced non-alcoholic liver disease (NAFLD) are needed to guide diagnostic evaluation and treatment. METHODS: To better understand the demographics of NAFLD and risk factors for advanced disease, this study analysed 827 patients with NAFLD at two geographically separate tertiary medical centres. RESULTS: The cohort was 51% female and had a median body mass index (BMI) of 33 kg/m(2); 3% had a normal BMI. Common co-morbidities included hypertension (60%) and diabetes (35%); insulin resistance was present in 91% and advanced fibrosis in 24% of patients. When comparing patients with no fibrosis or mild fibrosis to those with advanced fibrosis, BMI > or = 28 kg/m(2), age > 50 years, and aspartate transaminase/alanine aminotransferase (AST/ALT) ratio > or = 0.8, a quantitative assessment check index (QUICKI) score < 0.294 (equivalent to homeostasis model assessment (HOMA) > 6.2) and the presence of diabetes mellitus (DM) were individually associated by univariate analysis with odds ratios (ORs) of > or = 2.4 for advanced fibrosis. Based on the results of forced entry logistic regression analysis, three variables were combined in a weighted sum (BMI > or = 28 = 1 point, AAR of > or = 0.8 = 2 points, DM = 1 point) to form an easily calculated composite score for predicting advanced fibrosis called the BARD score. A score of 2-4 was associated with an OR for advanced fibrosis of 17 (confidence interval 9.2 to 31.9) and a negative predictive value of 96%. CONCLUSIONS: Insulin resistance and its co-morbidities are often present in patients with NAFLD. An easily calculated score based on readily available clinical data can reliably exclude the presence of advanced fibrosis in these patients, particularly among non-diabetics.

The present systematic review examined the relationship between nutrition knowledge and dietary intake in adults (mean age ≥ 18 years). Relevant databases were searched from the earliest record until November 2012. Search terms included: nutrition; diet or food knowledge and energy intake; feeding behaviour; diet; eating; nutrient or food intake or consumption. Included studies were original research articles that used instruments providing quantitative assessment of both nutrition knowledge and dietary intake and their statistical association. The initial search netted 1,193,393 potentially relevant articles, of which twenty-nine were eligible for inclusion. Most of them were conducted in community populations (n 22) with fewer (n 7) in athletic populations. Due to the heterogeneity of methods used to assess nutrition knowledge and dietary intake, a meta-analysis was not possible. The majority of the studies (65·5%: community 63·6%; athletic 71·4%) reported significant, positive, but weak (r< 0·5) associations between higher nutrition knowledge and dietary intake, most often a higher intake of fruit and vegetables. However, study quality ranged widely and participant representation from lower socio-economic status was limited, with most participants being tertiary educated and female. Well-designed studies using validated methodologies are needed to clarify the relationship between nutrition knowledge and dietary intake. Diet quality scores or indices that aim to evaluate compliance to dietary guidelines may be particularly valuable for assessing the relationship between nutrition knowledge and dietary intake. Nutrition knowledge is an integral component of health literacy and as low health literacy is associated with poor health outcomes, contemporary, high-quality research is needed to inform community nutrition education and public health policy.

The risk of posttraumatic stress disorder (PTSD) following trauma is heritable, but robust common variants have yet to be identified. In a multi-ethnic cohort including over 30,000 PTSD cases and 170,000 controls we conduct a genome-wide association study of PTSD. We demonstrate SNP-based heritability estimates of 5-20%, varying by sex. Three genome-wide significant loci are identified, 2 in European and 1 in African-ancestry analyses. Analyses stratified by sex implicate 3 additional loci in men. Along with other novel genes and non-coding RNAs, a Parkinson's disease gene involved in dopamine regulation, PARK2, is associated with PTSD. Finally, we demonstrate that polygenic risk for PTSD is significantly predictive of re-experiencing symptoms in the Million Veteran Program dataset, although specific loci did not replicate. These results demonstrate the role of genetic variation in the biology of risk for PTSD and highlight the necessity of conducting sex-stratified analyses and expanding GWAS beyond European ancestry populations.

BACKGROUND: Asymptomatic colonization with methicillin-resistant Staphylococcus aureus (MRSA) has been described as a risk factor for subsequent MRSA infection. MRSA is an important nosocomial pathogen but has currently been reported in patients without typical risk factors for nosocomial acquisition. This study was designed to evaluate the impact of asymptomatic nares MRSA colonization on the development of subsequent MRSA infection. The incidence of MRSA infection was examined in patients with and patients without MRSA or methicillin-susceptible S. aureus (MSSA) colonization at admission to the hospital and in those who developed colonization during hospitalization. METHODS: Patients admitted to 5 representative hospital units were prospectively evaluated. Nares samples were obtained for culture at admission and during hospitalization. Laboratory culture results were monitored to identify all MRSA infections that occurred during the study period and 1 year thereafter. RESULTS: Of the 758 patients who had cultures of nares samples performed at admission, 3.4% were colonized with MRSA, and 21% were colonized with MSSA. A total of 19% of patients with MRSA colonization at admission and 25% who acquired MRSA colonization during hospitalization developed infection with MRSA, compared with 1.5% and 2.0% of patients colonized with MSSA (P<.01) and uncolonized (P<.01), respectively, at admission. MRSA colonization at admission increased the risk of subsequent MRSA infection, compared with MSSA colonization (relative risk [RR], 13; 95% confidence interval [CI], 2.7-64) or no staphylococcal colonization (RR, 9.5; 95% CI, 3.6-25) at admission. Acquisition of MRSA colonization also increased the risk for subsequent MRSA infection, compared with no acquisition (RR, 12; 95% CI, 4.0-38). CONCLUSION: MRSA colonization of nares, either present at admission to the hospital or acquired during hospitalization, increases the risk for MRSA infection. Identifying MRSA colonization at admission could target a high-risk population that may benefit from interventions to decrease the risk for subsequent MRSA infection.

OBJECTIVE: To determine the short-term effects of using genotypic antiretroviral resistance testing (GART) with expert advice in the management of patients failing on a protease inhibitor and two nucleoside reverse transcriptase inhibitors. DESIGN: Prospective randomized controlled trial. SETTING: Multicenter community-based clinical trials network. PATIENTS: One-hundred and fifty-three HIV-infected adults with a threefold or greater rise in plasma HIV-1 RNA on at least 16 weeks of combination antiretroviral therapy. INTERVENTIONS: Randomization was either to a GART group, where genotype interpretation and suggested regimens were provided to clinicians, or to a no-GART group, where treatment choices were made without such input. MAIN OUTCOMES MEASURES: Plasma HIV-1 RNA levels and CD4 cell counts were measured at 4, 8, and 12 weeks following randomization. The primary endpoint was change in HIV-1 RNA levels from baseline to the average of the 4 and 8 week levels. RESULTS: The average baseline CD4 cell count was 230 x 10(6) cells/l and the median HIV-1 RNA was 28,085 copies/ml. At entry, 82 patients were failing on regimens containing indinavir, 51 on nelfinavir, 11 on ritonavir, and nine on saquinavir. HIV-1 RNA, averaged at 4 and 8 weeks, decreased by 1.19 log10 for the 78 GART patients and -0.61 log10 for the 75 no-GART patients (treatment difference: -0.53 log, 95% confidence interval, -0.77 to -0.29; P = 0.00001). Overall, the best virologic responses occurred in patients who received three or more drugs to which their HIV-1 appeared to be susceptible. CONCLUSION: In patients failing triple drug therapy, GART with expert advice was superior to no-GART as measured by short-term viral load responses.

IMPORTANCE: The US Army experienced a sharp increase in soldier suicides beginning in 2004. Administrative data reveal that among those at highest risk are soldiers in the 12 months after inpatient treatment of a psychiatric disorder. OBJECTIVE: To develop an actuarial risk algorithm predicting suicide in the 12 months after US Army soldier inpatient treatment of a psychiatric disorder to target expanded posthospitalization care. DESIGN, SETTING, AND PARTICIPANTS: There were 53,769 hospitalizations of active duty soldiers from January 1, 2004, through December 31, 2009, with International Classification of Diseases, Ninth Revision, Clinical Modification psychiatric admission diagnoses. Administrative data available before hospital discharge abstracted from a wide range of data systems (sociodemographic, US Army career, criminal justice, and medical or pharmacy) were used to predict suicides in the subsequent 12 months using machine learning methods (regression trees and penalized regressions) designed to evaluate cross-validated linear, nonlinear, and interactive predictive associations. MAIN OUTCOMES AND MEASURES: Suicides of soldiers hospitalized with psychiatric disorders in the 12 months after hospital discharge. RESULTS: Sixty-eight soldiers died by suicide within 12 months of hospital discharge (12.0% of all US Army suicides), equivalent to 263.9 suicides per 100,000 person-years compared with 18.5 suicides per 100,000 person-years in the total US Army. The strongest predictors included sociodemographics (male sex [odds ratio (OR), 7.9; 95% CI, 1.9-32.6] and late age of enlistment [OR, 1.9; 95% CI, 1.0-3.5]), criminal offenses (verbal violence [OR, 2.2; 95% CI, 1.2-4.0] and weapons possession [OR, 5.6; 95% CI, 1.7-18.3]), prior suicidality [OR, 2.9; 95% CI, 1.7-4.9], aspects of prior psychiatric inpatient and outpatient treatment (eg, number of antidepressant prescriptions filled in the past 12 months [OR, 1.3; 95% CI, 1.1-1.7]), and disorders diagnosed during the focal hospitalizations (eg, nonaffective psychosis [OR, 2.9; 95% CI, 1.2-7.0]). A total of 52.9% of posthospitalization suicides occurred after the 5% of hospitalizations with highest predicted suicide risk (3824.1 suicides per 100,000 person-years). These highest-risk hospitalizations also accounted for significantly elevated proportions of several other adverse posthospitalization outcomes (unintentional injury deaths, suicide attempts, and subsequent hospitalizations). CONCLUSIONS AND RELEVANCE: The high concentration of risk of suicide and other adverse outcomes might justify targeting expanded posthospitalization interventions to soldiers classified as having highest posthospitalization suicide risk, although final determination requires careful consideration of intervention costs, comparative effectiveness, and possible adverse effects.

OBJECTIVE: To evaluate battlefield survival in a novel command-directed casualty response system that comprehensively integrates Tactical Combat Casualty Care guidelines and a prehospital trauma registry. DESIGN: Analysis of battle injury data collected during combat deployments. SETTING: Afghanistan and Iraq from October 1, 2001, through March 31, 2010. PATIENTS: Casualties from the 75th Ranger Regiment, US Army Special Operations Command. MAIN OUTCOME MEASURES: Casualties were scrutinized for preventable adverse outcomes and opportunities to improve care. Comparisons were made with Department of Defense casualty data for the military as a whole. RESULTS: A total of 419 battle injury casualties were incurred during 7 years of continuous combat in Iraq and 8.5 years in Afghanistan. Despite higher casualty severity indicated by return-to-duty rates, the regiment's rates of 10.7% killed in action and 1.7% who died of wounds were lower than the Department of Defense rates of 16.4% and 5.8%, respectively, for the larger US military population (P = .04 and P = .02, respectively). Of 32 fatalities incurred by the regiment, none died of wounds from infection, none were potentially survivable through additional prehospital medical intervention, and 1 was potentially survivable in the hospital setting. Substantial prehospital care was provided by nonmedical personnel. CONCLUSIONS: A command-directed casualty response system that trains all personnel in Tactical Combat Casualty Care and receives continuous feedback from prehospital trauma registry data facilitated Tactical Combat Casualty Care performance improvements centered on clinical outcomes that resulted in unprecedented reduction of killed-in-action deaths, casualties who died of wounds, and preventable combat death. This data-driven approach is the model for improving prehospital trauma care and casualty outcomes on the battlefield and has considerable implications for civilian trauma systems.

Summary A technique for performing a plaque reduction test for dengue virus neutralizing antibody is described. Experiments designed to test the accuracy of the antibody measurement are presented and analysed by the method for a parallel line graded response assay. Statistical analysis indicates a high degree of accuracy, and the relative merits of this type of test for dengue neutralizing antibody are discussed.

OBJECTIVES: To determine the effect of acutely increased intra-abdominal pressure on pleural pressure, intracranial pressure, and cerebral perfusion pressure, and to clarify the relationship between these parameters. DESIGN: Nonrandomized, controlled study. SETTING: Laboratory at a university medical center. SUBJECTS: Yorkshire swine, weighing 15 to 20 kg. INTERVENTIONS: Anesthetized, ventilated swine had a balloon inserted into the peritoneal cavity and catheters placed for measurement of intracranial pressure, pleural pressure, central venous pressure, pulmonary artery occlusion pressure, and mean arterial pressure. Following baseline measurements, intra-abdominal pressure was increased by incrementally inflating the intraperitoneal balloon. All parameters were remeasured 30 mins after each increase in intra-abdominal pressure. Two groups were studied: a) group 1 (n = 9) animals had intra-abdominal pressure increased to 25 mm Hg above baseline, then released; b) group 2 (n = 3) animals underwent sternotomy and pleuropericardotomy to prevent an increase in pleural pressure with increasing intra-abdominal pressure. MEASUREMENTS AND MAIN RESULTS: Increase of intra-abdominal pressure to 25 mm Hg above baseline caused significant (p < .05) increases in intracranial pressure (7.3 +/- 0.6 [SEM] to 16.4 +/- 1.9 mm Hg), pleural pressure (4.3 +/- 1.3 to 11.8 +/- 1.9 mm Hg), pulmonary artery occlusion pressure (9.0 +/- 0.6 to 14.3 +/- 0.8 mm Hg), and central venous pressure (6.6 +/- 0.7 to 10.7 +/- 0.9 mm Hg). The cardiac index (3.4 +/- 0.3 to 1.6 +/- 0.1 L/min/m2) and cerebral perfusion pressure (75.6 +/- 3.6 to 62.0 +/- 6.8 mm Hg) deceased significantly (p < .05), whereas mean arterial pressure (82.8 +/- 3.2 to 78.4 +/- 6.6 mm Hg) remained essentially constant. Sternotomy and pleuro-pericardotomy negated all effects of increased intra-abdominal pressure except the decreased cardiac index (1.6 +/- 0.1 to 2.5 +/- 0.2 L/min/m2). CONCLUSIONS: Acutely increased intra-abdominal pressure causes a significant increase in intracranial pressure and a decrease in cerebral perfusion pressure. Increased intra-abdominal pressure appears to produce this effect by augmenting pleural and other intrathoracic pressures and causing a functional obstruction to cerebral venous outflow via the jugular venous system. It is possible that the same phenomenon may be why persons with chronically increased intra-abdominal pressure, such as the morbidly obese, suffer from a high frequency rate of idiopathic intracranial hypertension.

STUDY DESIGN: Reliability study. OBJECTIVES: To determine intrarater test-retest and interrater reliability of the Functional Movement Screen (FMS) among novice raters. BACKGROUND: The FMS is used by various examiners to assess movement and predict time-loss injuries in diverse populations (eg, youth to professional athletes, firefighters, military service members) of active participants. Unfortunately, critical analysis of the reliability of the FMS is currently limited to 1 sample of active college-age participants. METHODS: Sixty-four active-duty service members (mean ± SD age, 25.2 ± 3.8 years; body mass index, 25.1 ± 3.1 kg/m2) without a history of injury were enrolled. Participants completed the 7 component tests of the FMS in a counterbalanced order. Each component test was scored on an ordinal scale (0 to 3 points), resulting in a composite score ranging from 0 to 21 points. Intrarater test-retest reliability was assessed between baseline scores and those obtained with repeated testing performed 48 to 72 hours later. Interrater reliability was based on the assessment from 2 raters, selected from a pool of 8 novice raters, who assessed the same movements on day 2 simultaneously. Descriptive statistics, weighted kappa (κw), and percent agreement were calculated on component scores. Intraclass correlation coefficients (ICCs), standard error of the measurement, minimal detectable change (MDC95), and associated 95% confidence intervals (CIs) were calculated on composite scores. RESULTS: The average ± SD score on the FMS was 15.7 ± 0.2 points, with 15.6% (n = 10) of the participants scoring less than or equal to 14 points, the recommended cutoff for predicting time-loss injuries. The intrarater test-retest and interrater reliability of the FMS composite score resulted in an ICC3,1 of 0.76 (95% CI: 0.63, 0.85) and an ICC2,1 of 0.74 (95% CI: 0.60, 0.83), respectively. The standard error of the measurement of the composite test was within 1 point, and the MDC95 values were 2.1 and 2.5 points on the 21-point scale for interrater and intrarater reliability, respectively. The interrater agreement of the component scores ranged from moderate to excellent (κw = 0.45-0.82). CONCLUSION: Among novice raters, the FMS composite score demonstrated moderate to good interrater and intrarater reliability, with acceptable levels of measurement error. The measures of reliability and measurement error were similar for both intrarater reliability that repeated the assessment of the movement patterns over a 48-to-72-hour period and interrater reliability that had 2 raters assess the same movement pattern simultaneously. The interrater agreement of the FMS component scores was good to excellent for the push-up, quadruped, shoulder mobility, straight leg raise, squat, hurdle, and lunge. Only 15.6% (n = 10) of the participants were identified to be at risk for injury based on previously published cutoff values.

The Defense Medical Surveillance System (DMSS) is the central repository of medical surveillance data for the US armed forces. The DMSS integrates data from sources worldwide in a continuously expanding relational database that documents the military and medical experiences of service members throughout their careers. The Department of Defense Serum Repository (DoDSR) is a central archive of sera drawn from service members for medical surveillance purposes. Currently, the DMSS contains data relevant to more than 7 million individuals who have served in the armed forces since 1990, and the DoDSR contains more than 27 million specimens that are linkable to data in the DMSS. Recent applications of the DMSS and DoDSR provide glimpses of the capabilities and uses of comprehensive public health surveillance systems.

IMPORTANCE: The Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS) is a multicomponent study designed to generate actionable recommendations to reduce Army suicides and increase knowledge of risk and resilience factors for suicidality. OBJECTIVES: To present data on prevalence, trends, and basic sociodemographic and Army experience correlates of suicides and accident deaths among active duty Regular Army soldiers between January 1, 2004, and December 31, 2009, and thereby establish a foundation for future Army STARRS investigations. DESIGN, SETTING, AND PARTICIPANTS: Analysis of trends and predictors of suicide and accident deaths using Army and Department of Defense administrative data systems. Participants were all members of the US Regular Army serving at any time between 2004 and 2009. MAIN OUTCOMES AND MEASURES: Death by suicide or accident during active Army service. RESULTS: The suicide rate rose between 2004 and 2009 among never deployed and currently and previously deployed Regular Army soldiers. The accident death rate fell sharply among currently deployed soldiers, remained constant among the previously deployed, and trended upward among the never deployed. Increased suicide risk was associated with being a man (or a woman during deployment), white race/ethnicity, junior enlisted rank, recent demotion, and current or previous deployment. Sociodemographic and Army experience predictors were generally similar for suicides and accident deaths. Time trends in these predictors and in the Army's increased use of accession waivers (which relaxed some qualifications for new soldiers) do not explain the rise in Army suicides. CONCLUSIONS AND RELEVANCE: Predictors of Army suicides were largely similar to those reported elsewhere for civilians, although some predictors distinct to Army service emerged that deserve more in-depth analysis. The existence of a time trend in suicide risk among never-deployed soldiers argues indirectly against the view that exposure to combat-related trauma is the exclusive cause of the increase in Army suicides.

BACKGROUND: Both physical therapy and intraarticular injections of glucocorticoids have been shown to confer clinical benefit with respect to osteoarthritis of the knee. Whether the short-term and long-term effectiveness for relieving pain and improving physical function differ between these two therapies is uncertain. METHODS: We conducted a randomized trial to compare physical therapy with glucocorticoid injection in the primary care setting in the U.S. Military Health System. Patients with osteoarthritis in one or both knees were randomly assigned in a 1:1 ratio to receive a glucocorticoid injection or to undergo physical therapy. The primary outcome was the total score on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at 1 year (scores range from 0 to 240, with higher scores indicating worse pain, function, and stiffness). The secondary outcomes were the time needed to complete the Alternate Step Test, the time needed to complete the Timed Up and Go test, and the score on the Global Rating of Change scale, all assessed at 1 year. RESULTS: We enrolled 156 patients with a mean age of 56 years; 78 patients were assigned to each group. Baseline characteristics, including severity of pain and level of disability, were similar in the two groups. The mean (±SD) baseline WOMAC scores were 108.8±47.1 in the glucocorticoid injection group and 107.1±42.4 in the physical therapy group. At 1 year, the mean scores were 55.8±53.8 and 37.0±30.7, respectively (mean between-group difference, 18.8 points; 95% confidence interval, 5.0 to 32.6), a finding favoring physical therapy. Changes in secondary outcomes were in the same direction as those of the primary outcome. One patient fainted while receiving a glucocorticoid injection. CONCLUSIONS: Patients with osteoarthritis of the knee who underwent physical therapy had less pain and functional disability at 1 year than patients who received an intraarticular glucocorticoid injection. (ClinicalTrials.gov number, NCT01427153.).

Although computed tomography (CT) remains the most frequently used imaging examination in acute cerebral infarction, its sensitivity for early detection of strokes remains limited. In middle cerebral artery (MCA) strokes less than 6 hours old, loss of definition of the gray-white interface in the lateral margins of the insula ("insular ribbon") was observed. The acute and subacute CT findings in 11 retrospective and 16 prospective patients are presented. Loss of the insular ribbon was detected in 12 of the prospective cases and in all 11 retrospective cases. The insular ribbon is supplied by the insular segment of the MCA and its claustral branches. With cessation of MCA flow, the insular ribbon becomes the region most distal from the anterior and posterior cerebral collateral circulations. Consequently, the insular ribbon effectively becomes a watershed arterial zone. Loss of the insular ribbon is thus a reflection of acute edema due to infarction. Loss of the insular ribbon appears to be another frequent and reliable finding in acute MCA stroke.

The basic mechanisms of space radiation effects on microelectronics are reviewed. Topics discussed include the effects of displacement damage and ionizing radiation on devices and circuits, single-event phenomena, dose enhancement, radiation effects on optoelectronic devices and passive components, hardening approaches, and simulation of the space radiation environment. A summary of damage mechanisms that can cause temporary or permanent failure of devices and circuits operating in space is presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

PURPOSE: Functional movement screening (FMS) is a musculoskeletal assessment method that incorporates seven movements and yields an overall score based on movement quality. The objectives of this study were to document the distribution of scores and to determine whether FMS scores could predict injury in a large military cohort. METHODS: A cohort of 874 Marine officer candidates were recruited, consented, completed demographic questionnaires, and had FMS performed during medical in-processing. Candidates were enrolled in either long-cycle (LC: 68 d; n = 427) or short-cycle (SC: 38 d; n = 447) training and followed up for injuries occurring in training. RESULTS: The mean FMS score (score range = 0-21) among all candidates was 16.6 ± 1.7; approximately 10% of candidates had FMS scores ≤14. A score of ≤14 on the FMS predicted any injury with a sensitivity of 0.45 and a specificity of 0.71 and serious injury with a sensitivity of 0.12 and a specificity of 0.94. Both LC and SC cohorts demonstrated higher injury risk among candidates who had scores ≤14 compared with those with scores >14 (LC: risk ratio (RR) = 1.65, 95% confidence interval = 1.05-2.59, P = 0.03; SC: RR = 1.91, 95% confidence interval = 1.21-3.01, P < 0.01). Overall, 79.8% of persons with scores ≤14 were in the group with fitness scores <280 (/300), whereas only 6.6% of candidates in the group with fitness scores ≥280 had scores ≤14. CONCLUSIONS: This was the first large-scale study performed in an active-duty military cohort to examine the utility of FMS during medical in-processing. Further work is warranted to evaluate FMS and the potential for injury prediction and prevention.

INTRODUCTION: Noncombat injuries ("injuries") greatly impact soldier health and United States (U.S.) Army readiness; they are the leading cause of outpatient medical encounters (more than two million annually) among active component (AC) soldiers. Noncombat musculoskeletal injuries ("MSKIs") may account for nearly 60% of soldiers' limited duty days and 65% of soldiers who cannot deploy for medical reasons. Injuries primarily affect readiness through increased limited duty days, decreased deployability rates, and increased medical separation rates. MSKIs are also responsible for exorbitant medical costs to the U.S. government, including service-connected disability compensation. A significant subset of soldiers develops chronic pain or long-term disability after injury; this may increase their risk for chronic disease or secondary health deficits potentially associated with MSKIs. The authors will review trends in U.S. Army MSKI rates, summarize MSKI readiness-related impacts, and highlight the importance of standardizing surveillance approaches, including injury definitions used in injury surveillance. MATERIALS/METHODS: This review summarizes current reports and U.S. Department of Defense internal policy documents. MSKIs are defined as musculoskeletal disorders resulting from mechanical energy transfer, including traumatic and overuse injuries, which may cause pain and/or limit function. This review focuses on various U.S. Army populations, based on setting, sex, and age; the review excludes combat or battle injuries. RESULTS: More than half of all AC soldiers sustained at least one injury (MSKI or non-MSKI) in 2017. Overuse injuries comprise at least 70% of all injuries among AC soldiers. Female soldiers are at greater risk for MSKI than men. Female soldiers' aerobic and muscular fitness performances are typically lower than men's performances, which could account for their higher injury rates. Older soldiers are at greater injury risk than younger soldiers. Soldiers in noncombat arms units tend to have higher incidences of reported MSKIs, more limited duty days, and higher rates of limited duty days for chronic MSKIs than soldiers in combat arms units. MSKIs account for 65% of medically nondeployable AC soldiers. At any time, 4% of AC soldiers cannot deploy because of MSKIs. Once deployed, nonbattle injuries accounted for approximately 30% of all medical evacuations, and were the largest category of soldier evacuations from both recent major combat theaters (Iraq and Afghanistan). More than 85% of service members medically evacuated for MSKIs failed to return to the theater. MSKIs factored into (1) nearly 70% of medical disability discharges across the Army from 2011 through 2016 and (2) more than 90% of disability discharges within enlisted soldiers' first year of service from 2010 to 2015. MSKI-related, service-connected (SC) disabilities account for 44% of all SC disabilities (more than any other body system) among compensated U.S. Global War on Terrorism veterans. CONCLUSIONS: MSKIs significantly impact soldier health and U.S. Army readiness. MSKIs also figure prominently in medical disability discharges and long-term, service-connected disability costs. MSKI patterns and trends vary between trainees and soldiers in operational units and among military occupations and types of operational units. Coordinated injury surveillance efforts are needed to provide standardized metrics and accurately measure temporal changes in injury rates.

Microelectromechanical system (MEMS) and nanoelectromechanical system (NEMS) based resonators and filters, ranging in frequencies from kHz to GHz, have been proposed. The question of how the stabilities of such resonators scale with dimensions is examined in this paper, with emphasis on the noise characteristics. When the dimensions of a resonator become small, instabilities that are negligible in macro-scale devices become prominent. The effects of fluctuations in temperature, adsorbing/desorbing molecules, outgassing, Brownian motion, Johnson noise, drive power and self-heating, and random vibration are explored. When the device is small, the effects of fluctuations in the numbers of photons, phonons, electrons and adsorbed molecules can all affect the noise characteristics. For all but the random vibration-induced noise, reducing the dimensions increases the noise. At submicron dimensions, especially, the frequency noise due to temperature fluctuations, Johnson noise, and adsorption/desorption are likely to limit the applications of ultra-small resonators.

A new method of generating the Bessel functions and ratios of Bessel functions necessary for Mie calculations is presented. Accuracy is improved while eliminating the need for extended precision word lengths or large storage capability. The algorithm uses a new technique of evaluating continued fractions that starts at the beginning rather than the tail and has a built-in error check. The continued fraction representations for both spherical Bessel functions and ratios of Bessel functions of consecutive order are presented.

BACKGROUND: Among patients presenting with axial low back pain, facet arthropathy accounts for approximately 10-15% of cases. Facet interventions are the second most frequently performed procedures in pain clinics across the United States. Currently, there are no uniformly accepted criteria regarding how best to select patients for radiofrequency denervation. METHODS: A randomized, multicenter study was performed in 151 subjects with suspected lumbar facetogenic pain comparing three treatment paradigms. Group 0 received radiofrequency denervation based solely on clinical findings; group 1 underwent denervation contingent on a positive response to a single diagnostic block; and group 2 proceeded to denervation only if they obtained a positive response to comparative blocks done with lidocaine and bupivacaine. A positive outcome was predesignated as > or =50% pain relief coupled with a positive global perceived effect persisting for 3 months. RESULTS: In group 0, 17 patients (33%) obtained a successful outcome at 3 months versus eight patients (16%) in group 1 and 11 (22%) patients in group 2. Denervation success rates in groups 0, 1, and 2 were 33, 39, and 64%, respectively. Pain scores and functional capacity were significantly lower at 3 months but not at 1 month in group 2 subjects who proceeded to denervation compared with patients in groups 0 and 1. The costs per successful treatment in groups 0, 1, and 2 were $6,286, $17,142, and $15,241, respectively. CONCLUSIONS: Using current reimbursement scales, these findings suggest that proceeding to radiofrequency denervation without a diagnostic block is the most cost-effective treatment paradigm.