Risk factors for the presence and persistence of posttraumatic stress symptoms following traumatic brain injury in U.S. service members and veterans.

This study aimed to identify risk factors predictive of the presence and persistence of posttraumatic stress disorder (PTSD) symptom reporting following traumatic brain injury (TBI). Participants were 1,301 U.S. service members and veterans (SMVs) divided into four groups: uncomplicated mild TBI (mTBI; n = 543); complicated mild, moderate, severe, and penetrating TBI (n = 230); injured controls (n = 340); and noninjured controls (n = 188). We examined 25 factors related to demographic, injury-related, military-specific, treatment/health care need, and mental health/social support variables. Seven factors were statistically associated with the presence of DSM-IV-TR symptom criteria for PTSD: premorbid IQ, combat exposure, depression, social participation, history of mTBI, need for managing mood and stress, and need for improving memory and attention, p < .001 (51.3% variance). When comparing the prevalence of these risk factors in a longitudinal cohort (n = 742) across four PTSD trajectory groups (i.e., asymptomatic, improved, developed, persistent), a higher proportion of participants in the persistent PTSD group reported worse depression, a lack of social participation, and history of mTBI. Additionally, a higher proportion of participants in the persistent and developed PTSD groups reported the need for managing mood/stress and improving memory/attention. When considered simultaneously, the presence of ≥ 1 or ≥ 2 risk factors was associated with a higher proportion of participants in the developed and persistent PTSD groups, ps < .001. These risk factors may be useful in identifying SMVs at risk for the development and/or persistence of PTSD symptoms who may need intervention.

Clinical utility of PTSD, resilience, sleep, and blast as risk factors to predict poor neurobehavioral functioning following traumatic brain injury: A longitudinal study in U.S. military service members.

PURPOSE: This study examined the clinical utility of post-traumatic stress disorder (PTSD), low resilience, poor sleep, and lifetime blast exposure as risk factors for predicting future neurobehavioral outcome following traumatic brain injury (TBI). METHODS: Participants were 591 U.S. military service members and veterans who had sustained a TBI (n = 419) or orthopedic injury without TBI (n = 172). Participants completed the Neurobehavioral Symptom Inventory, PTSD Checklist, and the TBI-Quality of Life (TBI-QOL) scale at baseline and follow-up. RESULTS: Using the four risk factors at baseline, 15 risk factor combinations were examined by calculating odds ratios to predict poor neurobehavioral outcome at follow-up (i.e., number of abnormal scores across five TBI-QOL scales [e.g., Fatigue, Depression]). The vast majority of risk factor combinations resulted in odds ratios that were considered to be clinically meaningful (i.e., ≥ 2.5) for predicting poor outcome. The risk factor combinations with the highest odds ratios included PTSD singularly, or in combination with poor sleep and/or low resilience (odds ratios = 4.3-72.4). However, poor sleep and low resilience were also strong predictors in the absence of PTSD (odds ratios = 3.1-29.8). CONCLUSION: PTSD, poor sleep, and low resilience, singularly or in combination, may be valuable risk factors that can be used clinically for targeted early interventions.

Low resilience following traumatic brain injury is strongly associated with poor neurobehavioral functioning in U.S. military service members and veterans.

OBJECTIVE: The purpose of this study was to examine the relationship between resilience and self-reported neurobehavioral functioning following traumatic brain injury (TBI) in U.S. military service members and veterans (SMVs). A secondary objective was to examine the interaction between resilience and posttraumatic stress disorder (PTSD) on neurobehavioral functioning. METHOD: Participants included 795 SMVs classified into four groups: Uncomplicated Mild TBI (MTBI; n=300); Complicated Mild, Moderate, Severe, or Penetrating TBI (STBI, n 162); Injured Controls (IC, n=185); and Non-injured Controls (NIC, n=148). Two independent cohorts were evaluated - those assessed within 1-year of injury and those assessed 10-years post-injury. SMVs completed self-report measures including the PTSD Checklist-Civilian version, Neurobehavioral Symptom Inventory, and TBI-Quality of Life. RESULTS: Results showed that (1) lower resilience was strongly associated with poorer neurobehavioral functioning across all groups at 1-year and 10-years post-injury, and (2) PTSD and resilience had a robust influence on neurobehavioral functioning at both time periods post-injury, such that SMVs with PTSD and low resilience displayed the poorest neurobehavioral functioning. CONCLUSION: Results suggest that regardless of injury group and time since injury, resilience and PTSD strongly influence neurobehavioral functioning following TBI among SMVs. Future research evaluating interventions designed to enhance resilience in this population is indicated.

Impact of Prior Brain Injury on Concussion Recovery in Military Personnel: Evaluation of Timing Between Concussions.

OBJECTIVE: To evaluate the potential impact of timing between the current and the most recent previous concussions on symptom severity among acutely concussed active duty military Service members (SMs). SETTING: Three military installations. PARTICIPANTS: Eighty-four SMs aged 18 to 44 years who sustained a concussion within 72 hours of enrollment. No previous concussion within 1 year preenrollment. DESIGN: Longitudinal study with enrollment within 72 hours of injury, and follow-up at 1 week and 1 month postinjury. MAIN MEASURES: Lifetime concussion history (yes/no) and recency of the latest concussion (no history, relatively more recent [1 to <6 years ago], and more remote [6+ years ago]) from the current concussion using the Ohio State University Traumatic Brain Injury Identification Method-Interview Form. Symptom severity (total and by categories: cognitive, affective, somatosensory, vestibular) at all time points using the Neurobehavioral Symptoms Inventory. RESULTS: Concussion history assessed as having any previous concussion was not found significantly related to symptom severity (total or by categories) following a current concussion. However, when timing between concussion was taken into account, time since previous concussion was significantly related to symptomatology, whereby those with relatively more recent previous concussion had greater total symptoms within 72 hours of injury and at 1 week postinjury (though not at 1 month) than those with more remote previous concussion (≤72 hours: difference = 15.4, 95% CI = 1.8 to 29.1; 1 week: difference = 15.2, 95% CI = 1.2 to 29.2) or no history (≤72 hours: difference = 11.6, 95% CI = 0.4 to 22.8; 1 week: difference = 13.9, 95% CI = 2.4 to 25.4). When evaluated by symptom category, this relationship was particularly important on affective and somatosensory symptoms. CONCLUSION: In recently concussed active duty SMs, the timing between the current and previous concussions may be an important factor in determining prognosis. Clinical assessment of concussion history that accounts for the timing of the most recent event may be necessary to identify patients who may require a more conservative plan of care and more gradual return to activity in the acute recovery stage.

Intracranial Abnormalities Are Associated With Fewer Self-Reported Symptoms in Military Service Members Following Moderate-to-Severe Traumatic Brain Injury.

OBJECTIVE: This study examined the relationship between intracranial abnormalities (ICAs) and self-reported neurobehavioral and posttraumatic stress (PTS) symptoms in members of the military with moderate-to-severe traumatic brain injury (msTBI). METHOD: Participants included 539 members of the US military with nonpenetrating msTBI. Self-reported neurobehavioral and PTS symptoms were assessed using the Neurobehavioral Symptom Inventory and the PTSD Checklist-Civilian Version. ICAs were categorized as present/absent (by subtype) based upon medical record review. Spearman rank-order correlations and stepwise multiple regression analyses examined univariate and combined predictive relationships between ICAs and self-reported symptoms. RESULTS: The presence of any ICA was associated with reduced self-reported neurobehavioral and PTS symptoms. ICA-associated reductions were largest for PTS, followed by affective and cognitive neurobehavioral symptoms, and relatively weak for somatic/sensory and vestibular symptoms. Effects of different types of ICAs were comparable. Greater time since injury was related to greater symptom report, whereas duration of loss of consciousness and posttraumatic amnesia were not consistently related to self-reported symptoms. CONCLUSIONS: Results suggest that ICAs are associated with suppression of reported PTS and neurobehavioral symptoms-potentially via reduction in self-awareness. These findings support comprehensive, objective evaluation to identify impairments in self-awareness and functioning in msTBI patients.

Resilience is associated with health-related quality of life in caregivers of service members and veterans following traumatic brain injury.

PURPOSE: To examine factors related to resilience in military caregivers across caregiver health-related quality of life (HRQOL), caregiver sociodemographic variables, and service member/veteran (SMV) injury and health status. METHODS: Caregivers (N = 346, Female = 96.2%; Spouse = 91.0%; Age: M = 40.6 years, SD = 9.3) of SMVs following a mild, moderate, severe, or penetrating TBI were recruited from U.S. military treatment facilities and via community outreach. Caregivers completed select TBI-CareQOL and NIH Toolbox scales, the Caregiver Appraisal Scale, Caregiver Questionnaire, and Mayo-Portland Adaptability Inventory-4. Caregivers were divided into three groups using the TBI-QOL Resilience scale: (1) Low-Moderate Resilience (n = 125), (2) Moderate Resilience (n = 122), and (3) Moderate-High Resilience (n = 99). RESULTS: Factors related to low caregiver resilience were strain on employment, financial burden from out-of-pocket expenses, caring for children, less personal time, caring for both verbal and physical irritability, anger, and aggression, and lower SMV functional ability (all p's < .05). The Low-Moderate Resilience group had consistently worse HRQOL scores compared to the Moderate and Moderate-High Resilience groups (ps < .001; d = .50-1.60), with the exception of Caregiving Ideology. CONCLUSION: Lower resilience among caregivers of SMVs following TBI is associated with poorer caregiver HRQOL. Programs aimed at promoting and maintaining resilience in military caregivers long-term is important for their own health, the health of the SMV, and the health of their children.

Beliefs About the Influence of Rest During Concussion Recovery May Predict Activity and Symptom Progression Within an Active Duty Military Population.

OBJECTIVES: To evaluate relationships between beliefs about the impact of rest and the level of activities and symptoms over time among active duty Service members sustaining concussion, and whether these relationships vary by provision of concussion education. DESIGN: Longitudinal study using multilevel modeling to assess the relationship between beliefs about rest within 72 hours of concussion and change in activity and symptom level over time, as well as interaction by concussion education at the initial clinic visit. SETTING: Three military treatment facilities. PARTICIPANTS: Study participants included active duty Service members diagnosed with a concussion (N=111; median age, 24 y). Individuals with previous history of concussion within 12 months of study enrollment were excluded. INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Activity questionnaire and the Neurobehavioral Symptom Inventory assessed within 72 hours of concussion; at 1 week; and at 1, 3, and 6 month(s) postinjury. RESULTS: Receipt of concussion education from providers was significantly associated with greater belief that rest influences concussion recovery. Greater belief that rest influences symptom recovery at the acute stage of concussion was associated with a greater increase in activities over time, but only among those who received education from their provider. Additionally, greater belief about the influence of rest was related to a more rapid decrease in symptoms over time. CONCLUSIONS: Concussed Service members who underestimate the influence of rest during acute recovery may be at risk for poorer recovery. Treatment of Service members with postconcussive symptoms should consider patient knowledge and/or beliefs about rest and recovery, which may influence prognosis. Our results support the provider's use of concussion education to correct potential misconceptions that may negatively impact symptom recovery.

Activity Level During Acute Concussion May Predict Symptom Recovery Within an Active Duty Military Population.

OBJECTIVE: To evaluate the impact on symptom resolution of activity acutely following a concussion and the role of acute-phase symptoms on this relationship among active duty service members (SMs). SETTING: Three military installations. PARTICIPANTS: Sixty-two SMs aged 18 to 44 years who sustained a concussion within 72 hours of enrollment. DESIGN: Longitudinal design with data collected within 72 hours of injury (baseline, n = 62) and at 1 week (n = 57), 1 month (n = 50), 3 months (n = 41), and 6 months (n = 40) postinjury. MAIN MEASURES: Baseline activity level using a 60-item Activity Questionnaire. Symptom level at baseline and during follow-up using Neurobehavioral Symptoms Inventory. RESULTS: Significant interaction (Pi < .05) was found, with significant main effects (P < .05) limited to SMs with elevated baseline symptomatology. Among these participants, greater baseline total activity was significantly related to greater vestibular symptoms at 1, 3, and 6 months (ß = .61, .63, and .59, respectively). Significant associations were also found for particular types of baseline activity (eg, physical; vestibular/balance; military-specific) and symptoms at 1, 3, and/or 6 months postinjury. CONCLUSION: These results provide support for clinical guidance that symptomatic SMs, particularly those with high levels of acute symptoms, may need to avoid excessive activity acutely following concussion.

Posttraumatic Stress Disorder is a Stronger Predictor of Long-Term Neurobehavioral Outcomes Than Traumatic Brain Injury Severity.

Concurrent posttraumatic stress disorder (PTSD) and traumatic brain injury (TBI) is common in military populations. The purpose of this study was to examine long-term neurobehavioral outcomes in service members and veterans (SMVs) with versus without PTSD symptoms following TBI of all severities. Participants were 536 SMVs prospectively enrolled from three military medical treatment facilities who were recruited into three experimental groups: TBI, injured controls (IC), and noninjured controls (NIC). Participants completed the PTSD Checklist, Neurobehavioral Symptom Inventory, and the TBI-Quality of Life (TBI-QOL) and were divided into six subgroups based on the three experimental categories, two PTSD categories (i.e., present vs. absent), and two broad TBI severity categories (unMTBI, which included uncomplicated mild TBI; and smcTBI, which included severe TBI, moderate TBI, and complicated mild TBI): (a) NIC/PTSD-absent, (b) IC/PTSD-absent, (c) unMTBI/PTSD-absent, (d) unMTBI/PTSD-present, (e) smcTBI/PTSD-absent, and (f) smcTBI/PTSD-present. There were significant main effects across the six groups for all TBI-QOL measures, ps < .001. Select pairwise comparisons revealed significantly lower scores, p < .001, on all TBI-QOL measures in the PTSD-present groups when compared to the PTSD-absent groups within the same TBI severity classification, ds = 0.90-2.11. In contrast, when controlling for PTSD, there were no significant differences among the TBI severity groups for any TBI-QOL measures. These results provide support for the strong influence of PTSD but not TBI severity on neurobehavioral outcomes following TBI. Concurrent PTSD and TBI of all severities should be considered a risk factor for poor long-term neurobehavioral outcomes that require ongoing monitoring.

Long-term neurobehavioural symptom reporting following mild, moderate, severe, and penetrating traumatic brain injury in U.S. military service members.

The purpose of this study was to examine long-term neurobehavioural symptom reporting following mild, moderate, severe, or penetrating TBI in U.S. military service members and veterans (SMV). Participants were 445 SMVs divided into four groups: 158 uncomplicated mild TBI ("unMTBI" group), 105 penetrating, severe, moderate, or complicated mild TBI ("smcTBI" group), 101 injured controls (IC), and 81 non-injured controls (NIC). Two independent cohorts were examined that included participants 5-years or 10-year post-injury. Participants completed the TBI-Quality of Life, Neurobehavioural Symptom Inventory, and Post-traumatic Stress Disorder Checklist. At 5-years and 10-years post-injury, there were significant main effects for the majority of measures (all p's < .005). At 10-years post-injury, the NIC group had consistently better scores compared to the IC, unMTBI, and smcTBI groups. At 5-years post-injury, either (a) the IC and NIC group had better scores compared to both TBI groups, or (b) the NIC group had better scores compared to the IC, unMTBI, and smcTBI groups. A high proportion of SMVs reported poor long-term neurobehavioural symptoms following TBI or bodily injury without TBI. Injured SMVs (regardless of injury type) can have long-term symptoms that impact mental health and overall quality of life requiring long-term follow-up and care.

Postconcussion Symptom Reporting After Mild Traumatic Brain Injury in Female Service Members: Impact of Gender, Posttraumatic Stress Disorder, Severity of Injury, and Associated Bodily Injuries.

OBJECTIVE: Examine effects of diagnostically relevant posttraumatic stress disorder (PTSD) symptoms, mild traumatic brain injury (TBI) severity, and associated bodily injury severity on postconcussion symptom reporting in female service members (SM) compared with a matched sample of male SM. SETTING: Six US military medical treatment facilities. PARTICIPANTS: A total of 158 SM (79 females, 79 males) evaluated within 30 months after mild TBI. Men and women were matched by age, days postinjury, PTSD symptom status, mild TBI severity, and bodily injury severity. All passed a measure of symptom validity. DESIGN: Compare reported postconcussion symptoms for men and women stratified by PTSD diagnostic symptoms (present/absent), mild TBI severity (alteration of consciousness/loss of consciousness), and bodily injury severity (mild/moderate-severe). MAIN MEASURES: Neurobehavioral Symptom Inventory, PTSD Checklist, Abbreviated Injury Scale. RESULTS: Overall postconcussion symptom reporting increased with PTSD but did not significantly differ based on severity of mild TBI or associated bodily injury. Females reported more somatosensory and/or vestibular symptoms than males under some circumstances. Females in the PTSD-Present group, Alteration of Consciousness Only group, and Moderate-Severe Bodily Injury group reported more somatosensory symptoms than males in those groups. Females in the Alteration of Consciousness Only group and Minor Bodily Injury group reported more vestibular symptoms than males in those groups. CONCLUSION: Diagnostically relevant PTSD symptoms, mild TBI severity, and bodily injury severity differentially impact somatosensory and vestibular postconcussion symptom reporting for male and female SM after mild TBI. Controlling for PTSD and symptom validity resulted in fewer gender-based differences in postconcussive symptoms than previously demonstrated in the literature.

Clinical Utility and Psychometric Properties of the Traumatic Brain Injury Quality of Life Scale (TBI-QOL) in US Military Service Members.

OBJECTIVE: To examine the clinical utility and psychometric properties of the Traumatic Brain Injury Quality of Life (TBI-QOL) scale in a US military population. PARTICIPANTS: One hundred fifty-two US military service members (age: M = 34.3, SD = 9.4; 89.5% men) prospectively enrolled from the Walter Reed National Military Medical Center and other nationwide community outreach initiatives. Participants included 99 service members who had sustained a mild traumatic brain injury (TBI) and 53 injured or noninjured controls without TBI (n = 29 and n = 24, respectively). PROCEDURE: Participants completed the TBI-QOL scale and 5 other behavioral measures, on average, 33.8 months postinjury (SD = 37.9). MAIN OUTCOME MEASURES: Fourteen TBI-QOL subscales; Neurobehavioral Symptom Inventory; Posttraumatic Stress Disorder Checklist-Civilian version; Alcohol Use Disorders Identification Test; Combat Exposure Scale. RESULTS: The internal consistency reliability of the TBI-QOL scales ranged from α = .91 to α = .98. The convergent and discriminant validity of the 14 TBI-QOL subscales was high. The mild TBI group had significantly worse scores on 10 of the 14 TBI-QOL subscales than the control group (range, P < .001 to P = .043). Effect sizes ranged from medium to very large (d = 0.35 to d = 1.13). The largest differences were found on the Cognition-General Concerns (d = 1.13), Executive Function (d = 0.94), Grief-Loss (d = 0.88), Pain Interference (d = 0.83), and Headache Pain (d = 0.83) subscales. CONCLUSION: These results support the use of the TBI-QOL scale as a measure of health-related quality of life in a mild TBI military sample. Additional research is recommended to further evaluate the clinical utility of the TBI-QOL scale in both military and civilian settings.

Profile Analysis of the Neurobehavioral and Psychiatric Symptoms Following Combat-Related Mild Traumatic Brain Injury: Identification of Subtypes.

OBJECTIVE: To explore the taxonomy of combat-related mild traumatic brain injury (mTBI) based on symptom patterns. PARTICIPANTS: Up to 1341 military personnel who experienced a combat-related mTBI within 2 years of evaluation. MEASURES: Neurobehavioral Symptom Inventory and PTSD Checklist-Civilian Version (PCL-C). RESULTS: Cluster analysis revealed the following 4 subtypes: primarily psychiatric (posttraumatic stress disorder) group, a cognitive group, a mixed symptom group, and a good recovery group. The posttraumatic stress disorder cluster (21.9% of the sample) reported symptoms related to hyperarousal and dissociation/depression with few complaints related to cognition or headaches. The cognitive group (21.5% of the sample) had primarily cognitive and headache complaints with few mood symptoms. The mixed profile cluster included 18.6% of the sample and was characterized by a combination of mood complaints (hyperarousal and dissociation/depression), cognitive complaints, and headaches. The largest cluster (37.8% of the sample) had an overall low symptom profile and was labeled the "good recovery" group. CONCLUSIONS: The results support a unique taxonomy for combat-related mTBI. The clinical differences among these subtypes indicate a need for unique treatment resources and programs.

The experience, expression, and control of anger following traumatic brain injury in a military sample.

OBJECTIVE: To investigate the impact of traumatic brain injury (TBI) on the experience and expression of anger in a military sample. PARTICIPANTS: A total of 661 military personnel with a history of TBI and 1204 military personnel with no history of TBI. DESIGN: Cross-sectional, between-group design, using multivariate analysis of variance. MAIN MEASURE: State-Trait Anger Expression Inventory-2 (STAXI-2). RESULTS: Participants with a history of TBI had higher scores on the STAXI-2 than controls and were 2 to 3 times more likely than the participants in the control group to have at least 1 clinically significant elevation on the STAXI-2. Results suggested that greater time since injury (ie, months between TBI and assessment) was associated with lower scores on the STAXI-2 State Anger scale. CONCLUSION: Although the results do not take into account confounding psychiatric conditions and cannot address causality, they suggest that a history of TBI increases the risk of problems with the experience, expression, and control of anger. This bolsters the need for proper assessment of anger when evaluating TBI in a military cohort.

Cumulative Blast Exposure During a Military Career Negatively Impacts Recovery from Traumatic Brain Injury.

Sub-concussive injuries have emerged as an important factor in the long-term brain health of athletes and military personnel. The objective of this study was to explore the relationship between service member and veterans (SMVs) lifetime blast exposure and recovery from a traumatic brain injury (TBI). A total of 558 SMVs with a history of TBI were examined. Lifetime blast exposure (LBE) was based on self-report (M = 79.4, standard deviation = 392.6; range = 0-7500) categorized into three groups: Blast Naive (n = 121), Low LBE (n = 223; LBE range 1-9), and High LBE (n = 214; LBE >10). Dependent variables were the Neurobehavioral Symptom Inventory (NSI) and Post-traumatic Stress Disorder Checklist-Civilian (PCL-C) and the Traumatic Brain Injury Quality of Life (TBI-QOL). Analyses controlled for demographic factors (age, gender, and race) as well as TBI factors (months since index TBI, index TBI severity, and total number lifetime TBIs). The Blast Naive group had significantly lower NSI and PCL-C scores compared with the Low LBE group and High LBE group, with small to medium effect sizes. On the TBI-QOL, the Blast Naïve group had better quality life on 10 of the 14 scales examined. The Low LBE did not differ from the High LBE group on the PCL-C, NSI, or TBI-QOL. Blast exposure over an SMV's career was associated with increased neurobehavioral and post-traumatic stress symptoms following a TBI. The influence of psychological trauma associated with blasts may be an important factor influencing symptoms as well as the accuracy of self-reported estimates of LBE.

Lifetime blast exposure is not related to cognitive performance or psychiatric symptoms in US military personnel.

Objective: The present study aimed to examine the impact of lifetime blast exposure (LBE) on neuropsychological functioning in service members and veterans (SMVs). Method: Participants were 282 SMVs, with and without history of traumatic brain injury (TBI), who were prospectively enrolled in a Defense and Veterans Brain Injury Center (DVBIC)-Traumatic Brain Injury Center of Excellence (TBICoE) Longitudinal TBI Study. A cross-sectional analysis of baseline data was conducted. LBE was based on two factors: Military Occupational Speciality (MOS) and SMV self-report. Participants were divided into three groups based on LBE: Blast Naive (n = 61), Blast + Low Risk MOS (n = 96), Blast + High Risk MOS (n = 125). Multivariate analysis of variance (MANOVA) was used to examine group differences on neurocognitive domains and the Minnesota Multiphasic Personality Inventory-2 Restructured Form. Results: There were no statistically significant differences in attention/working memory, processing speed, executive functioning, and memory (Fs < 1.75, ps > .1, ηp2s < .032) or in General Cognition (Fs < 0.95, ps > .3, ηp2s < .008). Prior to correction for covariates, lifetime blast exposure was related to Restructured Clinical (F(18,542) = 1.77, p = .026, ηp2 = .055), Somatic/Cognitive (F(10,550) = 1.99, p = .033, ηp2 = .035), and Externalizing Scales (F(8,552) = 2.17, p = .028, ηp2 = .030); however, these relationships did not remain significant after correction for covariates (Fs < 1.53, ps > .145, ηp2s < .032). Conclusions: We did not find evidence of a relationship between LBE and neurocognitive performance or psychiatric symptoms. This stands in contrast to prior studies demonstrating an association between lifetime blast exposure and highly sensitive blood biomarkers and/or neuroimaging. Overall, findings suggest the neuropsychological impact of lifetime blast exposure is minimal in individuals remaining in or recently retired from military service.

Convergent and Discriminant Validity of the Blast Exposure Threshold Survey in United States Military Service Members and Veterans.

The Blast Exposure Threshold Survey (BETS) is a recently developed and promising new self-report measure of lifetime blast exposure (LBE). However, there are no studies that have examined the psychometric properties of the BETS, which currently limits its clinical utility. The purpose of this study was to examine the convergent and discriminant validity of the BETS by comparing the BETS Generalized Blast Exposure Value (GBEV) to six variables hypothesized to be associated with LBE (i.e., single-item LBE, combat exposure, years in the military, number of combat deployments, and military occupation specialty [MOS]) and three variables hypothesized not to be associated with LBE (i.e., age at the time of injury, estimated pre-morbid Full-Scale Intelligence Quotient [FSIQ], and resilience). Participants were 202 United States service members and veterans prospectively enrolled from three military medical treatment facilities (68.7%) and via community recruitment initiatives (31.3%). Participants completed the BETS, Combat Exposure Scale (CES), Deployment Risk and Resiliency Inventory-2 Combat Experiences (DRRI-2 CE), Traumatic Brain Injury-Quality of Life Resilience scale, and a brief structured interview. For some analyses, participants were classified into two blast risk MOS groups: high (n = 89) and low (n = 94). The BETS GBEV was not significantly correlated with all three non-blast related variables (rs = 0.01 to rs = -0.12). In contrast, GBEV was significantly (p < 0.001) associated with all blast-related variables; single-item LBE (rs = 0.76), CES (rs = 0.58), number of combat deployments (rs = 0.53), DRRI-2 CE (rs = 0.48), and high blast risk MOS (r = 0.36, medium effect size). However, a stronger relationship was found between the blast-related variables and three modified GBEV scores when excluding some small weapons categories; single-item LBE (rs = 0.80-0.82), CES (rs = 0.64-0.67), number of combat deployments (rs = 0.56), DRRI-2 CE (rs = 0.51-0.53), and high blast risk MOS (r = 0.42-0.49, medium-large effect size). This is the first study to examine the psychometric properties of the BETS. Overall, these results offer support for the convergent and discriminant validity of the BETS. In order to ensure that the BETS can be confidently used as a valid and reliable measure of LBE, more research is needed to further examine the psychometric properties of the test, particularly with regard to the establishment of test-retest reliability.

The Patient Global Impression of Change as a complementary tool to account for neurobehavioral and mental health symptom improvement for patients with concussion.

PURPOSE: The purpose of this study was to determine the extent to which patient's perspective of symptom improvement, as indexed by the Patient Global Impression of Change (PGIC) survey, is associated with symptom improvement on common measures of neurobehavioral and mental health symptoms following concussion. MATERIALS AND METHODS: Data were from 449 US active duty service members receiving treatment in interdisciplinary programs for their concussion. PGIC rating (range = 1-7) was evaluated for compatibility in assessing improvement in or clinically-elevated neurobehavioral (using Neurobehavioral Symptom Inventory [NSI]) and mental health (using Post-traumatic Stress Disorder Checklist, DSM-5 [PCL-5] and Patient Health Questionnaire [PHQ-8]) symptoms. RESULTS: Higher PGIC scores were related to a higher prevalence of clinically-relevant decrease in NSI, PCL-5 or PHQ-8 scores. Participants with a PGIC rating of 3+ (vs.<3) were about 2.2 (CI = 1.4-3.5), 1.6 (CI = 1.1-1.3), and 2.7 (CI = 1.4-5.1) times more likely to report clinically-relevant decrease in NSI, PCL-5 and PHQ-8 symptoms, respectively. CONCLUSION: PGIC may help providers incorporate patients' perspectives on symptom improvement achieved during rehabilitation. An approach combining PGIC with surveys such as NSI, PCL-5 and PHQ-8 may provide a more comprehensive understanding of symptom improvement and realistic view of expectations for what would be deemed recovery to pre-injury symptom levels.

Concussion significantly impacts cognitive, physical and mental health, and active duty service members (SMs) are at high risk due to their occupation demands.The Patient Global Impression of Change (PGIC) assesses symptom improvement, as perceived by the patient, which may align better with usual/pre-injury level symptoms prior to injury compared to other common measures of neurobehavioral and mental health symptoms for concussion patients.A comprehensive approach in which PGIC is included in symptom assessment may provide a better understanding of symptom improvement and provide a more realistic view of expectations for what would be deemed recovery to usual/pre-injury level or improvement in symptoms.

Gender Disparities in Neurobehavioral Symptoms and the Role of Post-Traumatic Symptoms in US Service Members Following Mild Traumatic Brain Injury.

Women are more directly involved in combat operations today than ever before, currently making up 18.6% of officers and 16.8% of enlisted personnel in the United States military. However, women continue to be under-represented in military research. Studies that do consider gender differences in traumatic brain injury (TBI) outcomes have shown that women report significantly more post-concussive symptoms than men. Conclusions for true gender differences related to TBI are hard to make without controlling for non-TBI factors. The effects previously identified in the literature may be an artifact of how men and women differ in their response to injury, unrelated to the neurological recovery process associated with TBI. The objective of this study was to examine the effects of gender specifics on mild TBI (mTBI) sequelae on injured and uninjured control groups, and to investigate the role of post-traumatic stress disorder (PTSD) on symptom reporting. It should be noted that the terms "gender" and "men/women" are used in this article in place of "sex" or "males/females" given that we are not discussing biological attributes. A total of 966 United States military service members and veterans were included in the study. Of the total sample, 455 men and 46 women were in the mTBI group, 285 men and 31 women were in the injured controls group (IC), and 111 men and 38 women in the non-injured controls group (NIC). Post-concussive and quality of life symptoms were compared for men and women while controlling for combat exposure. MTBI and IC groups were also stratified by PTSD presentation. Measures used included the Neurobehavioral Symptom Inventory (NSI), PTSD Checklist (PCL-C), Traumatic Brain Injury Quality of Life (TBI-QOL), and Combat Exposure Scale. In the mTBI group, women had worse scores on NSI total, NSI Somatosensory and Affective clusters, and the TBI-QOL Anxiety, Fatigue, and Headache scales (n2 = 0.018-0.032, small to small-medium effect sizes). When PTSD was present, women had worse scores on the NSI Somatosensory cluster only (n2 = 0.029, small-medium effect size). In contrast, when PTSD was absent, women had worse scores than men on the NSI Somatosensory and Affective clusters, and the TBI-QOL Anxiety and Headache scales (n2 = 0.032-0.063, small to medium effect sizes). In the IC group, women had worse scores on the NSI Cognitive cluster and the TBI-QOL Fatigue and Pain Interference scales (n2 = 0.024-0.042, small to small-medium effect sizes). However, group differences were no longer found when stratified by PTSD sub-groups. In the NIC group, there were no significant group differences for any analyses. We were able to identify symptoms unique to women recovering from mTBI that were not present following other forms of physical injury or in healthy controls. However, the impact of PTSD exacerbates the symptom profile and its comorbidity with mTBI equates to most of the noted gender differences.

High Lifetime Blast Exposure Using the Blast Exposure Threshold Survey Is Associated With Worse Warfighter Brain Health Following Mild Traumatic Brain Injury.

The purpose of this study was to extend previous research by examining the relationship between lifetime blast exposure and neurobehavioral functioning after mild TBI (MTBI) by (a) using a comprehensive measure of lifetime blast exposure, and (b) controlling for the influence of post-traumatic stress disorder (PTSD). Participants were 103 United States service members and veterans (SMVs) with a medically documented diagnosis of MTBI, recruited from three military treatment facilities (74.8%) and community-based recruitment initiatives (25.2%, e.g., social media, flyers). Participants completed a battery of neurobehavioral measures 12 or more months post-injury (Neurobehavioral Symptom Inventory, PTSD-Checklist PCLC, TBI-Quality of Life), including the Blast Exposure Threshold Survey (BETS). The sample was classified into two lifetime blast exposure (LBE) groups: High (n = 57) and Low (n = 46) LBE. In addition, the sample was classified into four LBE/PTSD subgroups: High PTSD/High LBE (n = 38); High PTSD/Low LBE (n = 19); Low PTSD/High LBE (n = 19); and Low PTSD/Low LBE (n = 27). The High LBE group had consistently worse scores on all neurobehavioral measures compared with the Low LBE group. When controlling for the influence of PTSD (using ANCOVA), however, only a handful of group differences remained. When comparing measures across the four LBE/PTSD subgroups, in the absence of clinically meaningful PTSD symptoms (i.e., Low PTSD), participants with High LBE had worse scores on the majority of neurobehavioral measures (e.g., post-concussion symptoms, sleep, fatigue). When examining the total number of clinically elevated measures, the High LBE subgroup consistently had a greater number of clinically elevated scores compared with the Low LBE subgroup for the majority of comparisons (i.e., four to 15 or more elevated symptoms). In contrast, in the presence of clinically meaningful PTSD symptoms (i.e., High PTSD), there were no differences between High versus Low LBE subgroups for all measures. When examining the total number of clinically elevated measures, however, there were meaningful differences between High versus Low LBE subgroups for those comparisons that included a high number of clinically elevated scores (i.e., six to 10 or more), but not for a low number of clinically elevated scores (i.e., one to five or more). High LBE, as quantified using a more comprehensive measure than utilized in past research (i.e., BETS), was associated with worse overall neurobehavioral functioning after MTBI. This study extends existing literature showing that lifetime blast exposure, that is largely subconcussive, may negatively impact warfighter brain health and readiness beyond diagnosable brain injury.