Using Rates of Low Scores to Assess Agreement between Brief Computerized Neuropsychological Assessment Batteries: A Clinically-based Approach for Psychometric Comparisons.

OBJECTIVE: To assess agreement between four brief computerized neurocognitive assessment tools (CNTs), ANAM, CogState, CNS Vital Signs, and ImPACT, by comparing rates of low scores. METHODS: Four hundred and six US Army service members (SMs) with and without acute mild traumatic brain injury completed two randomly assigned CNTs with order of administration also randomly assigned. We performed a base rate analysis for each CNT to determine the proportions of SMs in the control and mTBI groups who had various numbers of scores that were 1.0+, 1.5+, and 2.0+ standard deviations below the normative mean. We used these results to identify a hierarchy of low score levels ranging from poorest to least poor performance. We then compared the agreement between every low score level from each CNT pair administered to the SMs. RESULTS: More SMs in the mTBI group had low scores on all CNTs than SMs in the control group. As performance worsened, the association with mTBI became stronger for all CNTs. Most if not all SMs who performed at the worst level on any given CNT also had low scores on the other CNTs they completed but not necessarily at an equally low level. CONCLUSION: These results suggest that all of the CNTs we examined are broadly similar but still retain some psychometric differences that need to be better understood. Furthermore, the base rates of low scores we present could themselves be useful to clinicians and researchers as a guide for interpreting results from the CNTs.

Trajectory of Postconcussive Symptoms 12 Months After Deployment in Soldiers With and Without Mild Traumatic Brain Injury: Warrior Strong Study.

We analyzed data from a cohort of recently deployed soldiers from 2 US Army bases, Fort Carson and Fort Bragg (2009 to 2015). Soldiers with and without a recent history of mild traumatic brain injury (mTBI) on deployment were evaluated within days of return and at 3, 6, and 12 months. Those with mTBI were more likely than those without to endorse ≥1 postconcussive symptom as "severe" and/or "very severe" (47% vs. 21%, baseline; adjusted relative risk (RR) = 1.71, 95% confidence interval: 1.51, 1.93, all time points), which remained significant after adjusting for posttraumatic stress disorder (adjusted RR = 1.34, 95% confidence interval: 1.20, 1.50). Prevalence and relative risks for 3 of the most common baseline symptoms remained constant over time: sleep problems (RR = 2.19), forgetfulness (RR = 2.56), and irritability (RR = 2.73). The pattern was slightly different for headache (baseline, RR = 3.44; 12 months, RR = 3.26), due to increased prevalence of headache in those without mTBI. The prevalence of clinically relevant postconcussive symptoms remained relatively constant over 1 year of follow-up, whether or not symptoms were associated with concussion. Service members with recent mTBI reported more symptoms than those without at all time points.

A Comparison of Four Computerized Neurocognitive Assessment Tools to a Traditional Neuropsychological Test Battery in Service Members with and without Mild Traumatic Brain Injury.

OBJECTIVE: Computerized neurocognitive assessment tools (NCATS) are often used as a screening tool to identify cognitive deficits after mild traumatic brain injury (mTBI). However, differing methodology across studies renders it difficult to identify a consensus regarding the validity of NCATs. Thus, studies where multiple NCATs are administered in the same sample using the same methodology are warranted. METHOD: We investigated the validity of four NCATs: the ANAM4, CNS-VS, CogState, and ImPACT. Two NCATs were randomly assigned and a battery of traditional neuropsychological (NP) tests administered to healthy control active duty service members (n = 272) and to service members within 7 days of an mTBI (n = 231). Analyses included correlations between NCAT and the NP test scores to investigate convergent and discriminant validity, and regression analyses to identify the unique variance in NCAT and NP scores attributed to group status. Effect sizes (Cohen's f2) were calculated to guide interpretation of data. RESULTS: Only 37 (0.6%) of the 5,655 correlations calculated between NCATs and NP tests are large (i.e. r ≥ 0.50). The majority of correlations are small (i.e. 0.30 > r ≥ 0.10), with no clear patterns suggestive of convergent or discriminant validity between the NCATs and NP tests. Though there are statistically significant group differences across most NCAT and NP test scores, the unique variance accounted for by group status is minimal (i.e. semipartial R2 ≤ 0.033, 0.024, 0.062, and 0.011 for ANAM4, CNS-VS, CogState, and ImPACT, respectively), with effect sizes indicating small to no meaningful effect. CONCLUSION: Though the results are not overly promising for the validity of the four NCATs we investigated, traditional methods of investigating psychometric properties may not be appropriate for computerized tests. We offer several conceptual and methodological considerations for future studies regarding the validity of NCATs.

Long-Term Outcomes and Needs of Military Service Members After Noncombat-Related Traumatic Brain Injury.

OBJECTIVES: Assess the prevalence of self-identified unmet service needs in a military sample an average of 5 years following noncombat traumatic brain injury (TBI). Examine relationships between unmet needs and background, injury-related and outcome variables. METHODS: The study sample consisted of 89 veterans and service members who sustained non-combat TBI between 1999 and 2003, selected from enrollees in the Defense and Veterans Brain Injury Center TBI registry. Semistructured telephone interview was used to collect information about participants' self-reported unmet service needs, symptoms, and functional status. RESULTS: Most participants (65%) reported having at least one unmet service need. The most prevalent needs were "getting information about available post-TBI services" (47%) and "improving memory and attention" (45%). Unmet needs were associated with cognitive difficulties, physical and emotional symptoms, mental health diagnosis/treatment, and poorer functional status. CONCLUSIONS: Needs for services following TBI are associated with poor symptomatic and functional outcomes and may persist for years after injury in military service members and veterans. The study suggests service members' needs post TBI for improved cognition, support for emotional issues, and resources for vocational skills. Information about available services should be made accessible to those recovering from TBI to reduce the incidence of long-term unmet needs.

Soldiers returning from deployment: A qualitative study regarding exposure, coping, and reintegration.

PURPOSE/OBJECTIVE: The purpose of this study was to qualitatively explore exposure to deployment-related physical and/or emotional trauma and associated symptoms among Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) soldiers. Interviews also focused on in-theater- and reintegration-related experiences. RESEARCH METHOD/DESIGN: OEF/OIF soldiers (N = 103) participated in semistructured interviews, and a qualitative descriptive methodology was used to analyze the data. RESULTS: Themes were identified regarding (a) common experiences related to emotional and physical traumas and associated symptoms and strategies for coping and making meaning of experiences and (b) how combat and reintegration experiences affected soldiers' senses of self, relationships with others, and functioning. CONCLUSIONS/IMPLICATIONS: Themes identified support a rethinking of deployment-related mild traumatic brain injury and posttraumatic stress disorder as discrete conditions. Dimensional versus categorical models should be considered. The findings also highlight experiences and potentially meaningful constructs (e.g., moral injury, moral repair) that can be used to inform research and clinical efforts aimed at improving the lives of those who have served.

Update on the Epidemiology of Concussion/Mild Traumatic Brain Injury.

Mild traumatic injuries to the brain (e.g., concussion) are common and have been recognized since antiquity, although definitions have varied historically. Nonetheless, studying the epidemiology of concussion helps clarify the overall importance, risk factors, and at-risk populations for this injury. The present review will focus on recent findings related to the epidemiology of concussion including definition controversies, incidence, and patterns in the population overall and in the military and athlete populations specifically. Finally, as this is an area of active research, we will discuss how future epidemiologic observations hold promise for gaining greater clarity about concussion and mild traumatic brain injury.

Long-term functional outcomes of traumatic brain injury.

We review the literature on two long-term functional outcomes of traumatic brain injury (TBI) important to patients, family members, and rehabilitation treatment teams: work for pay and driving outcomes. Estimates on the percentages working after TBI have ranged widely, and few consistent prognostic indicators of long-term outcomes have been identified. The few large randomized controlled treatment trials of these long-term productive outcomes have been negative, but have identified promising subgroup results that bear further investigation. Salazar et al. (2000) identified patients with loss of consciousness of 1 hour or longer as a subgroup that benefited from intensive in-hospital treatment. Vanderploeg et al. (2008) found that the cognitive treatment arm resulted in improved cognitive performance, and that younger patients benefited more from the cognitive treatment; whereas older patients (31 plus) benefited from a more functional approach to treatment. The research evidence on driving post TBI is sparse - relying upon small studies, and lacking follow-up data. This review included only published research studies of 100 or more subjects, with control groups, and outcomes 6 months or longer after injury. The inclusion of more reliable studies narrowed return to work estimates and provided evidence that type of control group affects findings about return to work after mild TBI (mTBI). Prognostic indicators remain inconsistently measured among these more reliable studies. Heeding the frequent recommendation that research in this area be more stringently conducted, well powered, and use shared measures of critical variables would improve evidence. Adequately powered treatment trials of existing and innovative treatment modalities remain a priority.

Using base rates of low scores to interpret the ANAM4 TBI-MIL battery following mild traumatic brain injury.

Base rates of low ANAM4 TBI-MIL scores were calculated in a convenience sample of 733 healthy male active duty soldiers using available military reference values for the following cutoffs: ≤2nd percentile (2 SDs), ≤5th percentile, <10th percentile, and <16th percentile (1 SD). Rates of low scores were also calculated in 56 active duty male soldiers who sustained an mTBI an average of 23 days (SD = 36.1) prior. 22.0% of the healthy sample and 51.8% of the mTBI sample had two or more scores below 1 SD (i.e., 16th percentile). 18.8% of the healthy sample and 44.6% of the mTBI sample had one or more scores ≤5th percentile. Rates of low scores in the healthy sample were influenced by cutoffs and race/ethnicity. Importantly, some healthy soldiers obtain at least one low score on ANAM4. These base rate analyses can improve the methodology for interpreting ANAM4 performance in clinical practice and research.

Self-awareness and neurobehavioral outcomes, 5 years or more after moderate to severe brain injury.

OBJECTIVE: To examine self-awareness 5 years or more after traumatic brain injury (TBI) and its relation to outcomes. PARTICIPANTS: Sixty-two adults with moderate to severe TBI and significant other (SO) informants (family or close friend). SETTING: Regional veterans medical center. MAIN MEASURES: TBI Follow-up Interview, Community Integration Questionnaire, Satisfaction with Life Scale, and Caregiver Burden Inventory. DESIGN: Five to 16 years after acute inpatient rehabilitation, separate staff contacted and interviewed subjects and SOs. Subject awareness was defined as inverse subject-SO discrepancy scores. RESULTS: Subjects significantly underreported neurologic symptoms and overreported their work and home functioning; their self-ratings of emotional distress and social functioning did not differ from SO ratings. Employment was associated with greater self-awareness of cognitive deficits, even after controlling for injury severity. Subjects' life-satisfaction was associated with better self-reported neurologic functioning, which frequently did not agree with SO ratings. Caregiver burden was worse as SOs perceived subjects as having worse symptoms and poorer work and social integration. CONCLUSIONS: Impaired self-awareness remains evident more than 5 years after TBI. People with TBI are more likely to gain employment when they are aware of their cognitive deficits and abilities. However, subjective quality of life, for subjects and SOs, was related to their own perception of the TBI outcomes.

Self-reported mild TBI and postconcussive symptoms in a peacetime active duty military population: effect of multiple TBI history versus single mild TBI.

OBJECTIVE: To investigate the potential cumulative impact of mild traumatic brain injury (MTBI) on postconcussive symptoms. PARTICIPANTS: A total of 224 active duty soldiers reporting MTBI within 1 year of testing. For 101, this MTBI was their only reported traumatic brain injury (TBI); 123 had sustained at least 1 additional MTBI during their lifetime. A No TBI control group (n = 224) was included for comparison. MAIN MEASURE: Self-report symptoms data via questionnaire. Within time since injury subgroups (≤3 months; Post-3 months), symptom endorsement (no symptoms, 1 or 2 symptoms, 3+ symptoms) among soldiers with 1 MTBI was compared with that of soldiers with 2 or more MTBIs. Injured soldiers' symptom endorsement was compared with that of soldiers who had not sustained a TBI. RESULTS: Among the recently injured (≤3 months), those with 2 or more MTBIs endorsed significantly more symptoms than those with 1 MTBI: 67% of soldiers with 2 or more MTBIs reported 3+ symptoms, versus 29% of One MTBI soldiers. Among Post-3 month soldiers, there were no significant differences between MTBI groups. Overall, soldiers with MTBI endorsed significantly more symptoms than those without TBI. CONCLUSION: Past experience of MTBI may be a risk factor for increased symptom difficulty for several months postinjury. Clinicians should ascertain lifetime history of brain injury when evaluating patients for MTBI.

MTHFR C677T genotype as a risk factor for epilepsy including post-traumatic epilepsy in a representative military cohort.

The well-studied C677T variant in the methylenetetrahydrofolate reductase (MTHFR) enzyme is a biologically plausible genetic risk factor for seizures or epilepsy. First, plasma/serum levels of homocysteine, a pro-convulsant, are moderately elevated in individuals with the homozygote TT genotype. Furthermore, the TT genotype has been previously linked with migraine with aura-a comorbid condition-and with alcohol withdrawal seizures. Finally, several small studies have suggested that the TT genotype may be overrepresented in epilepsy patients. In this study, we consider whether the MTHFR C677T or A1298C variants are associated with risk of epilepsy including post-traumatic epilepsy (PTE) in a representative military cohort. Study subjects were selected from the cohort of military personnel on active duty during the years 2003 through 2007 who had archived serum samples at the DoD Serum Repository, essentially all active duty personnel during this time frame. We randomly selected 800 epilepsy patients and 800 matched controls based on ICD-9-CM diagnostic codes. We were able to isolate sufficient genetic material from the archived sera to genotype approximately 85% of our study subjects. The odds of epilepsy were increased in subjects with the TT versus CC genotype (crude OR=1.52 [1.04-2.22], p=0.031; adjusted OR=1.57 [1.07-2.32], p=0.023). In our sensitivity analysis, risk was most evident for patients with repeated rather than single medical encounters for epilepsy (crude OR=1.85 [1.14-2.97], p=0.011, adjusted OR=1.95 [1.19-3.19], p=0.008), and particularly for PTE (crude OR=3.14 [1.41-6.99], p=0.005; adjusted OR=2.55 [1.12-5.80], p=0.026). Our early results suggest a role for the common MTHFR C677T variant as a predisposing factors for epilepsy including PTE. Further exploration of baseline homocysteine and folate levels as predictors of seizure risk following traumatic brain injury is warranted.

Traumatic brain injury in the United States: an epidemiologic overview.

A basic description of severity and frequency is needed for planning healthcare delivery for any disease process. In the case of traumatic brain injury, severity is typically categorized into mild, moderate, and severe with information from a combination of clinical observation and self-report methodologies. Recent US civilian epidemiological findings measuring the frequency of mortality and morbidity of traumatic brain injury are presented, including demographic and etiological breakdowns of the data. Falls, motor vehicle accidents, and being struck by objects are the major etiologies of traumatic brain injury. US civilian and Army hospitalization trends are discussed and compared. Features of traumatic brain injuries from Operation Iraqi Freedom and Operation Enduring Freedom are discussed.

Performance on the Automated Neuropsychological Assessment Metrics in a nonclinical sample of soldiers screened for mild TBI after returning from Iraq and Afghanistan: a descriptive analysis.

PURPOSE: To characterize cognitive test performance in a sample of US Army soldiers who had served in Iraq and Afghanistan and were tested after returning to their home base. To determine whether if a self-reported history of deployment-related traumatic brain injury (TBI), lifetime history of TBI, and the current postconcussive symptom status affected cognitive test performance. METHODS: A convenience sample of 956 soldiers was administered the Automated Neuropsychological Assessment Metrics (ANAM) test battery as well as questionnaires asking about deployment-related TBI, lifetime TBI history, and current TBI-related symptoms. RESULTS: Consistent with past mild TBI (MTBI) research, having a history of deployment-related MTBI up to 2 years prior to cognitive testing was not associated with poor ANAM performance after deployment. There also were no associations between poor ANAM performance and the number of lifetime TBIs, and injury severity and the number of problematic postconcussive symptoms. CONCLUSIONS: A history of self-reported MTBI or current postconcussive symptoms does not increase the risk of cognitive impairment in service members returning from Iraq and Afghanistan.

Traumatic brain injury risk while parachuting: comparison of the personnel armor system for ground troops helmet and the advanced combat helmet.

Military paratroopers are inherently at risk for a variety of injuries when they jump, including traumatic brain injuries (TBIs). U.S. Army paratroopers rely on their ballistic helmets for protection against TBIs when jumping. Currently, two different helmets are available to Army paratroopers, that is, the personnel armor system for ground troops helmet and the advanced combat helmet. This study compared the incidence of self-reported, jump-related TBIs in a small sample of paratroopers (N = 585) using each type of helmet. Data were obtained from surveys of soldiers at Fort Bragg, North Carolina. The overall relative risk of sustaining a TBI while jumping was 2.3 times (95% confidence interval, 1.3-4.3) higher for personnel armor system for ground troops helmet users. Most of the increase in risk was accounted for by the most-minor TBIs (American Academy of Neurology grade 1 or 2 concussion).

Screening for traumatic brain injury in troops returning from deployment in Afghanistan and Iraq: initial investigation of the usefulness of a short screening tool for traumatic brain injury.

OBJECTIVE: Preliminary assessment of a new instrument, the Brief Traumatic Brain Injury Screen (BTBIS). DESIGN: Cross-sectional study of 596 soldiers returning from Iraq and/or Afghanistan, comparing the consistency of their reports of traumatic brain injury (TBI) across instruments with similar TBI questions, and in a brief follow-up interview. SETTING: Military base. MEASURES: Self-reported probable TBI on the BTBIS and on 2 longer questionnaires, and a brief follow-up interview. RESULTS: Self-reports of probable TBI were higher on the BTBIS, than on the longer instruments. Participants who screened positive on the BTBIS generally provided consistent information about probable TBI in the follow-up interview. CONCLUSIONS: In this initial study, the BTBIS demonstrated promise as part of a triage process in mass casualty situations, permitting individuals with probable TBI to self-report injury and continued symptoms. Further study, including full validation and reliability assessment, is warranted and required before these screening tools can be fully evaluated.

How satisfied are soldiers with their ballistic helmets? A comparison of soldiers' opinions about the advanced combat helmet and the personal armor system for ground troops helmet.

Many factors are considered during ballistic helmet design, including comfort, weight, fit, and maintainability. These factors affect soldiers' decisions about helmet use; therefore, rigorous research about soldiers' real-life experiences with helmets is critical to assessing a helmet's overall protective efficacy. This study compared soldiers' satisfaction and problem experience with the advanced combat helmet (ACH) and the personal armor system for ground troops (PASGT) helmet. Data were obtained from surveys of soldiers at Fort Bragg, North Carolina. Ninety percent of ACH users were satisfied overall with their helmet, but only 9.5% of PASGT users were satisfied (p < 0.001). The most frequently reported problems for the ACH involved malfunctioning helmet parts. The most frequently reported problems for the PASGT involved discomfort. This analysis indicated that there was a strong soldier preference for the ACH over the PASGT, which could enhance its already superior protective qualities. It also demonstrated the usefulness of soldiers' assessments of protective equipment.

Hospital admissions associated with traumatic brain injury in the US Army during peacetime: 1990s trends.

INTRODUCTION: This paper examines 10-year trends in traumatic brain injury (TBI)-related hospitalization rates for active duty US Army personnel in the 1990s. It does this within the context of various factors, including enhanced injury prevention policies and changed hospital admission practices, that may have affected TBI hospitalization rates. It also compares TBI hospitalization rates in the Army to those from an age-comparable segment of the US civilian population over this time period. METHODS: Crude (unadjusted) incidence rates for all active duty US Army personnel hospitalized with a TBI diagnosis from fiscal years (FY) 1990 to 1999 were calculated. Once the trends were identified, the percentage change in the overall rate, as well as the rates for different TBI severity levels, and in-hospital deaths from FY1990 and FY1999 were analyzed. Changes in age- and gender-specific rates as well as crude rates for cases with and without other injuries and cases treated in military and civilian hospitals were also analyzed. Rate ratios were used to compare aggregated 5-year TBI hospitalization rates in the Army to rates for civilians 17-49 years of age during the following time periods: 1990-1994 and 1995-1999. The rates used in the comparison were adjusted to control for differences in age and gender. RESULTS: The overall incidence of TBI-related hospitalization in the Army decreased 75% from FY1990 to FY1999. The rates for all TBI severity levels decreased, but the rate for mild TBI decreased more than the rates for moderate and severe TBI. The rate of in-hospital deaths from TBI also decreased. Rates decreased similarly for males and females, across all age groups, as well as for cases with and without other injuries. TBI rates decreased for Army personnel treated in military hospitals but changed minimally for Army personnel treated in civilian hospitals. The Army's TBI hospitalization rates were generally higher than civilian rates in the early 1990s but by the late 1990s, most of the Army's rates were lower than or equal to the civilian rates. CONCLUSIONS: The incidence of TBI-related hospitalization in the active duty US Army decreased markedly (75%) during the 1990s. As a result, most of the Army's TBI hospitalization rates were lower than civilian rates by the late 1990s. Effective injury prevention and changes in the Army population were two of the factors that likely contributed to the decrease in rates for all TBI severity levels, while changes in hospital admission practices likely contributed to the disproportionate decrease in the Army's rates for mild TBI.