Lakmini Bulathsinhala

Risk Factors for Soft Tissue Knee Injuries in Active Duty U.S. Army Soldiers, 2000–2005

BACKGROUND There is a scarcity of analytic research on active duty Army (ADA) knee injuries (KI), such as soft tissue knee injuries (STKI), which are the predominant ADA KI pattern. PURPOSE To quantify the independent adjusted association of significant ADA STKI risk factors, 2000-2005. MATERIALS/METHODS Using the Total Army Injury and Health Outcomes Database, we (1) captured absolute STKI numbers and rates (N = 83,323) and (2) developed regression models to determine significant STKI risk factors. Models included STKI overall and subcategories: meniscus, patella, anterior/posterior cruciate ligament, and medial/lateral cruciate ligament. RESULTS Eight risk factors significantly increased STKI. They are: (1) prior KI (within 2 years) (odds ratio [OR] 9.83, 95% confidence interval [CI] 9.67-10.00); (2) increasing length of service (OR 1.83, 95% CI 1.76-1.90); (3) increasing age (OR 1.57, 95% CI 1.50-1.65); (4) prior deployment (OR 1.39, 95% CI 1.36-1.41); (5) prior ankle injury (OR 1.16, 95% CI 1.14-1.19); (6) Infantry occupation (OR 1.12, 95% CI 1.04-1.21); (7) marital status (OR 1.10, 95% CI 1.08-1.12); (8) and prior hip injury (OR 1.08, 95% CI 1.03-1.12). MAJOR CONCLUSION Soldiers with a prior KI have nearly a 10-fold increased relative risk of developing a subsequent STKI.

Rates of Knee Injury in the U.S. Active Duty Army, 2000–2005

We sought to summarize knee injuries (KI) in the U.S. Active Duty Army (ADA) in terms of absolute numbers, examine current rate trends, and identify ADA who were at increased risk for experiencing a KI. We used the Total Army Injury and Health Outcomes Database (TAIHOD) to compute unadjusted and adjusted rates of KI, categorized by the Barell Matrix, within the ADA for the years 2000-2005. During this period, 21 to 25 per 1,000 ADA suffered from KI. The highest yearly rates were observed for knee dislocation and sprains/strains (31 per 1,000 ADA). In ADA with a history of a KI (within 2 years), rates increased nearly tenfold. Elevated KI rates were also seen in ADA with prior upper or lower leg injuries, those > 30 years of age, and those with a category IV Armed Forces Qualification Test score (lowest admissible in Army). ADA KI rates remained fairly stable throughout the study period. Relative to other ADA Soldiers, those with prior knee, upper leg, or lower leg injuries are at increased risk for subsequent KI.

Trends in overweight and obesity in soldiers entering the US Army, 1989-2012.

The US Army recruits new soldiers from an increasingly obese civilian population. The change in weight status at entry into the Army between 1989 and 2012 and the demographic characteristics associated with overweight/obesity at entry were examined.

Risk of Stress Fracture Varies by Race/Ethnic Origin in a Cohort Study of 1.3 Million U.S. Army Soldiers†

Stress fractures (SF) are common and costly injuries in military personnel. Risk for SF has been shown to vary with race/ethnicity. Previous studies report increased SF risk in white and Hispanic Soldiers compared with black Soldiers. However, these studies did not account for the large ethnic diversity in the US military. We aimed to identify differences in SF risk among racial/ethnic groups within the US Army. A retrospective cohort study was conducted using data from the Total Army Injury and Health Outcomes Database from 2001 until 2011. SF diagnoses were identified from ICD‐9 codes. We used Cox‐proportional hazard models to calculate time to SF by racial/ethnic group after adjusting for age, education, and body mass index. We performed a sex‐stratified analysis to determine whether the ethnic variation in SF risk depends on sex. We identified 21,549 SF cases in 1,299,332 Soldiers (more than 5,228,525 person‐years of risk), revealing an overall incidence rate of 4.12 per 1000 person‐years (7.47 and 2.05 per 1000 person‐years in women and men, respectively). Using non‐Hispanic blacks as the referent group, non‐Hispanic white women had the highest risk of SF, with a 92% higher risk of SF than non‐Hispanic black women (1.92 [1.81–2.03]), followed by American Indian/Native Alaskan women (1.72 [1.44–1.79]), Hispanic women (1.65 [1.53–1.79]), and Asian women (1.32 [1.16–1.49]). Similarly, non‐Hispanic white men had the highest risk of SF, with a 59% higher risk of SF than non‐Hispanic black men (1.59 [1.50–1.68]), followed by Hispanic men (1.19 [1.10–1.29]). When examining the total US Army population, we found substantial differences in the risk of stress fracture among racial/ethnic groups, with non‐Hispanic white Soldiers at greatest risk and Hispanic, American Indian/Native Alaskan, and Asian Soldiers at an intermediate risk. Additional studies are needed to determine the factors underlying these race‐ and ethnic‐related differences in stress fracture risk.

BMI and Lower Extremity Injury in U.S. Army Soldiers, 2001–2011

INTRODUCTION Little data exist regarding the long-term impact of excess weight on lower extremity musculoskeletal injury/disorder (MID) in U.S. Army Soldiers. This prospective analysis examines the association between BMI of Soldiers at accession and risk of MID. METHODS A total of 736,608 Soldiers were followed from accession into the Army, 2001-2011. Data were analyzed January through March 2015. MID was categorized as any first incident lower extremity musculoskeletal injury/disorder, and secondarily, as first incident injury/disorder at a specific site (i.e., hips, upper legs/thighs, knees, lower legs/ankles, feet/toes). Multivariable-adjusted proportional hazards models estimated associations between BMI category at accession and MID risk. RESULTS During 15,678,743 person-months of follow-up, 411,413 cases of any first MID were documented (70,578 hip, 77,050 upper leg, 162,041 knee, 338,080 lower leg, and 100,935 foot injuries in secondary analyses). The overall MID rate was 2.62 per 100 person-months. Relative to Soldiers with normal BMI (18.5 to <25 kg/m(2)) at accession, those who were underweight (<18.5); overweight (25 to <30); or obese (≥30) had 7%, 11%, and 33% higher risk of MID, respectively, after adjustment. Risks were highest in Soldiers who were obese at accession, and lowest in those with a BMI of 21-23 kg/m(2). CONCLUSIONS Soldier BMI at accession has important implications for MID. A BMI of 21-23 kg/m(2) in newly accessing Soldiers was associated with the lowest risk of incident MID, suggesting that accession be limited to people within this range to reduce overall incidence of MID among service personnel.

Epidemiology of Ankle Sprains and the Risk of Separation From Service in US Army Soldiers

STUDY DESIGN Retrospective cohort study. OBJECTIVES To report the incidence rate of ankle sprains in active-duty soldiers and to examine if soldiers who sustain ankle sprain injuries are more likely to leave the Army than those who do not sustain an ankle sprain. BACKGROUND Ankle sprains are one of the most common musculoskeletal injuries in physically active people and have been identified as the most common foot or ankle injury in active-duty Army personnel, with a rate of 103 sprains per 1000 soldiers per year. METHODS Data were analyzed on the entire active-duty US Army population from 2000 to 2006 (n = 1 014 042). A semi-parametric Cox proportional hazard model was built. RESULTS The overall incidence rate for ankle sprains was 45.14 per 1000 person-years. After controlling for length of service prior to the study period, soldiers who sustained a single ankle sprain were 27% less likely (relative risk ratio = 0.73; 95% confidence interval: 0.73, 0.75) to leave the service than soldiers who had no documented history of an ankle sprain. However, this trend toward increased service time no longer held true for those who sustained a recurrent sprain (risk ratio = 1.07; 95% confidence interval: 0.99, 1.15). CONCLUSION It appears that individuals who sustain an incident ankle sprain have longer time in service in the Army than those who do not sustain this injury. However, this trend toward longer service time no longer held true for soldiers who sustained a recurrent. LEVEL OF EVIDENCE Prognosis, level 2b.

Prevalence, health care utilization, and costs of fibromyalgia, irritable bowel, and chronic fatigue syndromes in the military health system, 2006-2010.

OBJECTIVE We compared prevalence, health care utilization, and costs over time for nonelderly adults diagnosed with fibromyalgia syndrome (FMS), irritable bowel syndrome (IBS), and chronic fatigue syndrome (CFS) in relation to timing of federal approvals for FMS drugs. DATA SOURCE We used military health care claims from October 2006 to September 2010. STUDY DESIGN/ANALYSIS Retrospective, multiple-year comparisons were conducted using trend analyses, and time series regression-based generalized linear models. RESULTS Over 5 years, FMS prevalence rates increased from 0.307% to 0.522%, whereas IBS and CFS prevalence rates remained stable. The largest increase in FMS prevalence occurred between 2007 and 2008. Health care utilization was higher for FMS cases compared to IBS and CFS cases. Over 5 years, the total cost for FMS-related care increased

Methodological challenges of using U.S. army administrative data to identify a cohort of basic combat trainees and descriptive analysis of trends in characteristics that are potential risk factors for training-related injury

163.2 million, whereas IBS costs increased

Risk Factors for Rhabdomyolysis in the U.S. Army

14.9 million and CFS cost increased

Nonsteroidal Anti-Inflammatory Drug Prescriptions are Associated with Increased Stress Fracture Diagnosis in the U.S. Army Population

3.7 million. Between 2006 and 2010, total pharmacy cost for FMS cases increased from