Expanding capabilities to evaluate readiness for return to duty after mTBI: The CAMP study protocol.

Physical Therapists affiliated with Intrepid Spirit Centers evaluate and treat Active Duty Service Members (ADSM) who have duty-limiting post-concussion symptoms to improve the ability to perform challenging tasks associated with military service. The Complex Assessment of Military Performance (CAMP) is a test battery that more closely approximates the occupational demands of ADSM without specific adherence to a particular branch of service or military occupational specialty. Subtasks were developed with military collaborators to include high level skills that all service members must be able to perform such as reacting quickly, maintaining visual stability while moving and changing positions, and scanning for, noting, and/or remembering operationally relevant information under conditions of physical exertion. OBJECTIVE: The purpose of this observational longitudinal study is to: 1- establish typical performance parameters for ADSM on the CAMP test battery 2- determine the element of the CAMP battery that demonstrate the greatest differences from standard performance and serve as predictors for successful return to duty and 3- develop clinician-facing feedback algorithms and displays and 4-develop materials for clinical dissemination. This ongoing multi-site study is currently funded through the CDMRP and has been approved by the Naval Medical Center Portsmouth IRB. METHODS: ADSM undergoing post-concussion rehabilitation at the Intrepid Spirit Centers will be tested within one week of their initial Physical Therapy evaluation and after completing Physical Therapy. Control participants will include males, females, and ADSM from the Special Operations community. Participants will complete an intake form that includes questions about demographics, military service, deployment and concussion history, and profile and duty status. Other measures include those that explore concussion symptoms, sleep quality, post-traumatic stress, and perceptions of resilience. The CAMP includes three separate 10-15 minute tasks. Movement is recorded by wearable inertial sensors and heart rate variability is recorded with a POLAR10 monitor. The "Run-Roll" task requires rapid position changes, combat rolls and quick running forwards and backwards while carrying a simulated weapon. Visual stability before and after the task is also performed. The "Dual-Task Agility" task includes rapid running with and without a weighted vest and a working memory task. The "Patrol Exertion" task requires repeated stepping onto an exercise step while watching a virtual patrol video. Additional tasks include monitoring direction of travel, observing for signs of enemy presence, and reacting to multiple auditory signals embedded in the video. DISCUSSION: Measures that evaluate relevant skills are vital to support safe return to duty for ADSM who may be exposed to imminent danger as part of training or mission demands. The CAMP is designed to be an ecologically valid and clinically feasible assessment that may be more sensitive to capturing subtle impairments that impact duty performance as test skills are integrated into dual and multi-tasks that reflect occupational demands. Assessment results may serve as a more robust indicator of readiness for full return to duty after concussion.

Prevalence of Neck Pain in Soldiers as a Result of Mild Traumatic Brain Injury-Associated Trauma.

INTRODUCTION: Many of the injury mechanisms that cause mild traumatic brain injury (mTBI) also create forces commonly associated with whiplash, resulting in cervical pain injury. The prevalence of associated neck pain with mTBI is not well established. There is a strong indication that injury to the cervical spine may aggravate, cause, and/or impact recovery of symptoms and impairments associated with the concussive event and its primary effect on the brain. The purpose of this study is to help identify the prevalence of ensuing cervical pain within 90 days of a previously documented mTBI and to examine the role of neck pain during concurrent concussive symptoms, in a military population stationed at a large military installation. MATERIALS AND METHODS: This retrospective design utilized a de-identified dataset using predetermined search and filter criteria, which included male active duty service members (SMs), 20 to 45 years of age, who received medical care at any clinic on Fort Liberty (Fort Bragg, NC) during fiscal year (FY) 2012 to FY 2019, with documented cervicalgia and mTBI (via the International Classification of Diseases, 9th and 10th Revision, Clinical Modification codes), verified using electronic medical records. The final dataset served as the basis for subject sampling and was analyzed to determine the total number of documented cervicalgia and mTBI diagnoses. Results are presented as descriptive statistics. Approval for this study was received from the Andrews University Office of Research (18-097) and the Womack Army Medical Center Human Protections Office. RESULTS: Between FY 2012 and FY 2019, 14,352 unique SMs accessed a Fort Bragg, NC health care facility, at least once (Table I). Overall, 52% of SMs diagnosed with cervicalgia were found to have a previously diagnosed mTBI during the 90 days before the cervicalgia diagnosis. In contrast, the prevalence of same-day cervicalgia and mTBI diagnosis was <1% (Table IV). The prevalence of isolated cervicalgia diagnosis at any time during the reporting period was 3%, whereas isolated mTBI diagnosis was 1% (Table III). CONCLUSIONS: Over 50% of SMs diagnosed with cervicalgia had sustained a documented mTBI within 90 days prior, whereas less than 1% were diagnosed with cervicalgia at the time of initial primary care or emergency room encounter following the mTBI event. This finding suggests that the close anatomical and neurophysiological connections between the head and the cervical spine are both likely to be impacted through the same mechanism of injury. Delayed evaluation (and treatment) of the cervical spine may contribute to lingering post-concussive symptoms. Limitations of this retrospective review include the inability to assess the causality of the relationship between neck pain and mTBI, as only the existence and strength of the prevalence relationship can be identified. The outcome data are exploratory and intended to identify relationships and trends that may suggest further study across installations and across mTBI populations.

Validity and Responsiveness of the Portable Warrior Test of Tactical Agility After Rehabilitation in Service Members With Mild Traumatic Brain Injury.

OBJECTIVE: The Portable Warrior Test of Tactical Agility (POWAR-TOTAL) is a performance-based test designed to assess active-duty service members diagnosed with mild traumatic brain injuries (mTBIs) and could potentially inform return to duty decisions. To examine the validity and responsiveness of the POWAR-TOTAL measure, this study collected self-reported and performance measures by active-duty service members before and after an episode of physical therapist care. METHODS: Seventy-four individuals, enrolled in care for mTBI symptoms at 1 of 2 concussion specialty Intrepid Spirit Centers, were examined the week that they initiated physical therapy with the intention to return to active duty. Self-reported measures of concussion symptoms, pain, posttraumatic stress, headache, dizziness, and sleep quality were used, as were concurrent measures of mobility and balance. The POWAR-TOTAL task (motor and cognitive skills in single and dual-task conditions) was administered. Forty-nine active-duty service members returned for posttherapy testing using the same test battery. Effect sizes for change in measures were calculated. Construct validity was assessed by correlating change scores on POWAR with concurrent self-report and mobility measures. Responsiveness was evaluated using an anchor-based approach. RESULTS: Significant improvements in self-reported and performance-based measures, including POWAR, were observed after therapy with moderate to large effect sizes. Improvement in POWAR performance correlated with improvement in both performance and self-reported measures. After therapy, individuals who registered improvement on the Patient Global Impression of Change scale demonstrated significantly faster POWAR motor performance than those who rated little or no improvement in their condition. CONCLUSION: The POWAR-TOTAL captured improvement on a military-specific task after completing physical therapy for mTBI and could serve as an indicator of physical recovery and readiness for return to duty. IMPACT: Challenging cognitive and motor measures for service members may aid in the assessment of recovery and the ability to successfully return to duty after concussion as part of a comprehensive examination approach.

The Portable Warrior Test of Tactical Agility: A Novel Functional Assessment That Discriminates Service Members Diagnosed With Concussion From Controls.

INTRODUCTION: Return-to-duty (RTD) readiness assessment for service members (SM) following concussion requires complex clinical considerations. The Portable Warrior Test of Tactical Agility (POWAR-TOTAL) is a functional assessment which improves on previous laboratory-based RTD assessments. METHODS: Sixty-four SM diagnosed with concussion and 60 healthy control (HC) SM participated in this study. Group differences were analyzed to validate the POWAR-TOTAL. The High-level Mobility Assessment Test (HiMAT) was used to examine concurrent construct validity. An exploratory logistic regression analysis examined predictive validity. RESULTS: The groups were demographically well-matched except for educational level. POWAR-TOTAL measures were statistically significantly different between the groups with moderate to large effect sizes. Concussed participants were less likely to be able to complete all trials of the POWAR-TOTAL. Motor scores correlated highly with HiMAT scores. POWAR-TOTAL motor task performance and membership in the control group was significantly associated with self-reported physical readiness to deploy. CONCLUSION: The POWAR-TOTAL is a clinically feasible, military relevant assessment that is sensitive to differences between concussed and HC SM. This analysis supports the discriminant and construct validity of the POWAR-TOTAL, and may be useful for medical providers evaluating RTD readiness for SM who have sustained a concussion.

Wearable Sensors Detect Movement Differences in the Portable Warrior Test of Tactical Agility After mTBI in Service Members.

INTRODUCTION: Assessment of functional recovery of service members following a concussion is central to their return to duty. Practical military-relevant performance-based tests are needed for identifying those who might need specialized rehabilitation, for evaluating the progress of recovery, and for making return-to-duty determinations. One such recently developed test is the 'Portable Warrior Test of Tactical Agility' (POWAR-TOTAL) assessment designed for use following concussion in an active duty population. This agility task involves maneuvers used in military training, such as rapid stand-to-prone and prone-to-stand transitions, combat rolls, and forward and backward running. The effect of concussion on the performance of such maneuvers has not been established. MATERIALS AND METHODS: The Institutional Review Board-approved study was conducted at Ft. Bragg, North Carolina, on 57 healthy control (HC) service members (SMs) and 42 well-matched SMs who were diagnosed with concussion and were referred for physical therapy with the intent to return to duty. Each study participant performed five consecutive trials of the POWAR-TOTAL task at full exertion while wearing inertial sensors, which were used to identify the constituent task maneuvers, or phases, and measure their durations. Statistical analyses were performed on durations of three main phases: (1) rising from prone and running, (2) lowering from vertical to prone, and (3) combat rolls. RESULTS: None of the three phases showed significant correlation with age (range 18-45 years) in either group. Gradual improvement in all three phase durations across five trials was observed in the HC group, but not in the concussed group. On average, control subjects performed significantly faster (P < .004 or less) than concussed subjects in all trials in the lowering and rolling phases, but less so in the rising/running phase. Membership in the concussed group had a strong effect on the lowering phase (Cohen's d = 1.05), medium effect on the rolling phase (d = 0.72), and small effect on the rising/running phase (d = 0.49). Individuals in the HC group who had a history of prior concussions were intermediate between the concussed group and the never-concussed group in the lowering and rolling phases. Duration of transitional movements (lowering from standing to prone and combat rolls) was better at differentiating individuals' performance by group (receiver operating characteristic area under the curve [AUC] = 0.83) than the duration of the entire POWAR-TOTAL task (AUC = 0.71). CONCLUSIONS: Inertial sensor analysis reveals that rapid transitional movements (such as lowering from vertical to prone position and combat rolls) are particularly discriminative between SMs recovering from concussion and their concussion-free peers. This analysis supports the validity of POWAR-TOTAL as a useful tool for therapists who serve military SMs.

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.

"Return to duty" as an outcome metric in military concussion research: Problems, pitfalls, and potential solutions.

OBJECTIVE: "Return to duty" (RTD) is often used as an outcome metric in military concussion research, but is inconsistently defined across studies and presents several key problems to researchers. Using results from the Defense and Veterans Brain Injury Center's (DVBIC) Progressive Return to Activity (PRA) study, we highlight problems with RTD, and suggest solutions to inform future efforts. METHOD: 116 service members (SMs) were enrolled in one of two groups (pre-implementation and post-implementation of the PRA Clinical Recommendation [CR]). Data, including the Neurobehavioral Symptom Inventory (NSI-22), was collected within 72-hours of injury (baseline), and at 1-week, 1-month, 3-months, and 6-months post-injury. Our analyses focused on three time points: baseline, approximate RTD date, and post-RTD follow-up, with RTD data captured via self-report and electronic medical record (EMR). Secondary analyses included comparisons across PRA-CR implementation groups. RESULTS: Of those SMs (<50% of the sample) with both self-reported and EMR RTD dates, dates largely did not match (range 1 to 36 days). RTD (either date) also did not indicate symptom recovery, with >50% of SMs reporting "abnormally high" symptom levels (i.e., NSI-22 total ≥75th percentile) at RTD, and over 50% of SMs reporting at least one significant symptom (i.e., any NSI-22 item ≥ 2) after RTD. CONCLUSIONS: Our data demonstrate challenges encountered with a RTD outcome metric. Military concussion researchers should strive to use a well-defined RTD outcome metric. We propose defining RTD as a return to deployment readiness. Further, researchers should utilize Department of Defense definitions of Individual Medical Readiness and Deployment Limiting conditions to increase specificity of a RTD outcome metric. Improving the way RTD is captured will improve confidence that tools used after a SM sustains concussion are adequately informing RTD decisions.

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.

Use of the Progressive Return to Activity Guidelines May Expedite Symptom Resolution After Concussion for Active Duty Military.

BACKGROUND: Clinical recommendations for concussion management encourage reduced cognitive and physical activities immediately after injury, with graded increases in activity as symptoms resolve. Empirical support for the effectiveness of such recommendations is needed. PURPOSE: To examine whether training medical providers on the Defense and Veterans Brain Injury Center's Progressive Return to Activity Clinical Recommendation (PRA-CR) for acute concussion improves patient outcomes. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: This study was conducted from 2016 to 2018 and compared patient outcomes before and after medical providers received an educational intervention (ie, provider training). Patients, recruited either before or after intervention, were assessed at ≤72 hours, 1 week, 1 month, 3 months, and 6 months after a concussion. The participant population included 38 military medical providers and 106 military servicemembers with a diagnosed concussion and treated by one of the military medical providers: 58 patient participants received care before the intervention (ie, provider training) and 48 received care after intervention. The primary outcome measure was the Neurobehavioral Symptom Inventory. RESULTS: The patients seen before and after the intervention were predominantly male (89.7% and 93.8%, respectively) of military age (mean ± SD, 26.62 ± 6.29 years and 25.08 ± 6.85 years, respectively) and a mean ± SD of 1.92 ± 0.88 days from injury. Compared with patients receiving care before intervention, patients receiving care after intervention had smaller increases in physical activities (difference in mean change; 95% CI, 0.39 to 6.79) and vestibular/balance activities (95% CI, 0.79 to 7.5) during the first week of recovery. Although groups did not differ in symptoms at ≤72 hours of injury (d = 0.22; 95% CI, -2.21 to 8.07), the postintervention group reported fewer symptoms at 1 week (d = 0.61; 95% CI, 0.52 to 10.92). Postintervention patients who completed the 6-month study had improved recovery both at 1 month (d = 1.55; 95% CI, 5.33 to 15.39) and 3 months after injury (d = 1.10; 95% CI, 2.36 to 11.55), but not at 6 months (d = 0.35; 95% CI, 5.34 to 7.59). CONCLUSION: Training medical providers on the PRA-CR for management of concussion resulted in expedited recovery of patients.

Activity Level and Type During Post-acute Stages of Concussion May Play an Important Role in Improving Symptoms Among an Active Duty Military Population.

Background: Previous research demonstrates that early rest and gradual increases in activity after concussion can improve symptoms; however, little is known about the intensity and type of activity during post-acute time periods-specifically months post-injury-that may promote optimal recovery in an active duty service member (SM) population. Objective: The objectives of this study were to investigate how activity level and type at the post-acute stages of concussion (at 1 and 3 month[s] post-injury) impact subsequent symptoms among SMs, and how this relationship might differ by the level of symptoms at the time of injury. Methods: Participants included 39 SMs ages 19-44 years from 3 military installations who were enrolled within 72 h after sustaining a concussion. Linear regression was used to evaluate whether the association between activity level at 1 or 3 month(s) post-injury (as measured by a multi-domain Activity Questionnaire) and subsequent symptoms at 3 and/or 6 months (as measured by the Neurobehavioral Symptom Inventory) varied by the level of symptoms at acute stages of concussion. Partial correlation was used to evaluate relationships that did not differ by acute symptom level. Symptoms at the time of activity assessment (1 or 3 month[s]) were accounted for in all models, as well as activity level at acute stages of concussion. Results: Greater physical and vestibular/balance activity at 1 month were significantly correlated with lower symptoms at 3 months, but not at 6 months post-injury. There were no significant associations found between activity (total or by type) at 3 months and symptoms at 6 months. The association between activity level at either 1 or 3 months and subsequent symptoms at 3 and/or 6 months did not differ by the level of acute symptoms. Conclusion: The intensity and type of activities in which SMs engage at post-acute stages of concussion may impact symptom recovery. Although low levels of activity have been previously shown to be beneficial during the acute stage of injury, higher levels of activity may provide benefit at later stages. These findings provide support for the importance of monitoring and managing activity level beyond the acute stage of concussion.

Clinical Utility and Analysis of the Run-Roll-Aim Task: Informing Return-to-Duty Readiness Decisions in Active-Duty Service Members.

INTRODUCTION: The Assessment of Military Multitasking Performance (AMMP1) consists of six dual-task and multitask military-relevant performance-based assessments which were developed to provide assistance in making return-to-duty decisions after concussion or mild traumatic brain injury (mTBI.) The Run-Roll-Aim (RRA) task, one component of the AMMP, was developed to target vulnerabilities following mTBI including attention, visual function, dynamic stability, rapid transition, and vestibular function. One aim of this study was to assess the known-group and construct validity of the RRA, and additionally to further explore reliability limitations reported previously. MATERIALS AND METHODS: A cross-sectional study consisting of 84 Active Duty service members in two groups (healthy control - HC and individuals experiencing persistent mTBI symptoms) completed neurocognitive tests and the RRA. The RRA task requires a high level of mobility and resembles military training activities in a maneuver that includes combat rolls, fast transitions, obstacle avoidance, and visual search. Observational and inertial sensor data were compared between groups and performance across four trial times was compared within groups. Correlations between RRA results and neurocognitive test scores were analyzed. RESULTS: Simple observational measures (time, errors) did not differ between groups. Spectral power analysis of the inertial sensor data showed significant differences in motor performance between groups. Within group one-way ANOVAs showed that in HC trial 1, time was significantly different than trials 2,3 and 4 (F(3,47) = 4.60, p < 0.01, Tukey HSD p < 0.05) while the mTBI group showed no significant difference in time between trials. During testing individuals with mTBI were less likely to complete the multiple test trials or required additional rest between trials than HCs (χ2 = 10.78, p < 0.01). Small but significant correlations were seen with two neurocognitive tests of attention and RRA performance time. CONCLUSION: While observational scores were not sensitive to group differences, inertial sensor data showed motor performance on the forward run, combat roll, and backward run differed significantly between groups. The RRA task appeared challenging and provoked symptoms in the mTBI group, causing 8 of 33 mTBI participants to stop the task or require additional rest between trials while none of the HC participants had to stop. Individuals with mTBI demonstrated slower learning of the complex motor sequence compared to HCs who had significant improvement after one trial of RRA. Complex novel training maneuvers like RRA may aid clinicians in informing return to duty decisions.

Toward Return to Duty Decision-Making After Military Mild Traumatic Brain Injury: Preliminary Validation of the Charge of Quarters Duty Test.

Introduction: Determining duty-readiness after mild traumatic brain injury (mTBI) remains a priority of the United States Department of Defense as warfighters in both deployed and non-deployed settings continue to sustain these injuries in relatively large numbers. Warfighters with mTBI may experience unresolved sensorimotor, emotional, cognitive sequelae including problems with executive functions, a category of higher order cognitive processes that enable people to regulate goal-directed behavior. Persistent mTBI sequelae interfere with warfighters' proficiency in performing military duties and signal the need for graded return to activity and possibly rehabilitative services. Although significant strides have been carried out in recent years to enhance the identification and management of mTBI in garrison (EXORD 165-13) and deployed settings (EXORD 242-11; DoDI 6,490.11), the Department of Defense still lacks reliable, valid, and clinically feasible functional assessments to help inform duty-readiness decisions. Traditional functional assessments lack face validity for warfighters and may have ceiling effects, especially as related to executive functions. Performance-based multitasking assessments have been shown to be sensitive to executive dysfunction after acquired brain injury but no multitasking assessments have been validated in adults with mTBI. Existing multitasking assessments are not ecologically valid relative to military contexts. A multidisciplinary military-civilian team of researchers developed and evaluated a performance-based assessment called the Assessment of Military Multitasking Performance. One of the Assessment of Military Multitasking Performance multitasks, the Charge of Quarters Duty Test (CQDT), was designed to challenge the divided attention, foresight, and planning dimensions of executive functions. Here, we report on the preliminary validation results of the CQDT. Materials and Methods: The team conducted a measurement development study at Fort Bragg, NC, enrolling 83 service members (33 with mTBI and 50 healthy controls). Discriminant validity was evaluated by comparing differences in CQDT sub-scores of warfighters with mTBI and healthy controls. Associations between CQDT sub-scores and neurocognitive measures known to be sensitive to mTBI were examined to explore convergent validity. The study was approved by the Womack Army Medical Center Institutional Review Board (Fort Bragg). Results: There were significant between-group differences in two of the four CQDT sub-scores (number of visits, p = 0.012; and performance accuracy, p = 0.020). Correlations between the CQDT sub-scores and some neurocognitive measures were statistically significant but weak, ranging from 0.287 (CQDT performance accuracy and NAB Numbers and Letters, Part D) to -0.421 (CQDT total number of visits and Automated Neuropsychological Assessment Metrics Tower Task). There were group differences in terms of participants' reading level, education, years in military, and stress symptoms; some of these characteristics may have influenced CQDT performance. Conclusions: The CQDT demonstrated initial evidence of discriminant validity. Further study is warranted to more formally evaluate convergent/divergent validity and ultimately how and whether this performance-based multitasking measure can inform readiness to return to duty after mTBI.

Measuring Soldier Performance During the Patrol-Exertion Multitask: Preliminary Validation of a Postconcussive Functional Return-to-Duty Metric.

OBJECTIVE: To assess the discriminant validity of the Patrol-Exertion Multitask (PEMT), a novel, multidomain, functional return-to-duty clinical assessment for active duty military personnel. DESIGN: Measurement development study. SETTING: Nonclinical indoor testing facility. PARTICIPANTS: Participants (N=84) were healthy control (HC) service members (SMs; n=51) and military personnel (n=33) with persistent postconcussive symptoms receiving rehabilitation (mild traumatic brain injury [mTBI]). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Known-groups discriminant validity was evaluated by comparing performance on the PEMT in 2 groups of active duty SMs: HCs and personnel with mTBI residual symptoms. Participant PEMT performance was based on responses in 4 subtasks during a 12-minute patrolling scenario: (1) accuracy in identifying virtual improvised explosive device (IED) markers and responses to scenario-derived questions from a computer-simulated foot patrol; (2) auditory reaction time responses; (3) rating of perceived exertion during stepping; and (4) self-reported visual clarity (ie, gaze stability) during vertical head-in-space translation while stepping. RESULTS: Significant between-group differences for the PEMT were observed in 2 of 4 performance domains. Postpatrol IED identification task/question responses (P=.179) and rating of perceived exertion (P=.133) did not discriminate between groups. Participant self-report of visual clarity during stepping revealed significant (P<.001) between-group differences. SM reaction time responses to scenario-based auditory cues were significantly delayed in the mTBI group in both the early (P=.013) and late (P=.002) stages of the PEMT. CONCLUSIONS: Findings from this study support the use of a naturalistic, multidomain, complex clinical assessment to discriminate between healthy SMs and personnel with mTBI residual symptoms. Based on this preliminary study, additional research to further refine the PEMT and extend its application to return-to-work outcomes in military and civilian environments is warranted.

Further Development of the Assessment of Military Multitasking Performance: Iterative Reliability Testing.

The Assessment of Military Multitasking Performance (AMMP) is a battery of functional dual-tasks and multitasks based on military activities that target known sensorimotor, cognitive, and exertional vulnerabilities after concussion/mild traumatic brain injury (mTBI). The AMMP was developed to help address known limitations in post concussive return to duty assessment and decision making. Once validated, the AMMP is intended for use in combination with other metrics to inform duty-readiness decisions in Active Duty Service Members following concussion. This study used an iterative process of repeated interrater reliability testing and feasibility feedback to drive modifications to the 9 tasks of the original AMMP which resulted in a final version of 6 tasks with metrics that demonstrated clinically acceptable ICCs of > 0.92 (range of 0.92-1.0) for the 3 dual tasks and > 0.87 (range 0.87-1.0) for the metrics of the 3 multitasks. Three metrics involved in recording subject errors across 2 tasks did not achieve ICCs above 0.85 set apriori for multitasks (0.64) and above 0.90 set for dual-tasks (0.77 and 0.86) and were not used for further analysis. This iterative process involved 3 phases of testing with between 13 and 26 subjects, ages 18-42 years, tested in each phase from a combined cohort of healthy controls and Service Members with mTBI. Study findings support continued validation of this assessment tool to provide rehabilitation clinicians further return to duty assessment methods robust to ceiling effects with strong face validity to injured Warriors and their leaders.

Military-Civilian Collaborations for mTBI Rehabilitation Research in an Active Duty Population: Lessons Learned From the Assessment of Military Multitasking Performance Project.

This article describes lessons learned in the planning, development, and administration of a collaborative military-civilian research project, the Assessment of Military Multitasking Performance, which was designed to address a gap in clinical assessment for active duty service members with mild traumatic brain injury who wish to return to active duty. Our team worked over the course of multiple years to develop an assessment for military therapists to address this need. Insights gained through trial and error are shared to provide guidance for civilian researchers who may wish to collaborate with active duty researchers.

Use of a multi-level mixed methods approach to study the effectiveness of a primary care progressive return to activity protocol after acute mild traumatic brain injury/concussion in the military.

The large number of U.S. service members diagnosed with concussion/mild traumatic brain injury each year underscores the necessity for clear and effective clinical guidance for managing concussion. Relevant research continues to emerge supporting a gradual return to pre-injury activity levels without aggravating symptoms; however, available guidance does not provide detailed standards for this return to activity process. To fill this gap, the Defense and Veterans Brain Injury Center released a recommendation for primary care providers detailing a step-wise return to unrestricted activity during the acute phase of concussion. This guidance was developed in collaboration with an interdisciplinary group of clinical, military, and academic subject matter experts using an evidence-based approach. Systematic evaluation of the guidance is critical to ensure positive patient outcomes, to discover barriers to implementation by providers, and to identify ways to improve the recommendation. Here we describe a multi-level, mixed-methods approach to evaluate the recommendation incorporating outcomes from both patients and providers. Procedures were developed to implement the study within complex but ecologically-valid settings at multiple military treatment facilities and operational medical units. Special consideration was given to anticipated challenges such as the frequent movement of military personnel, selection of appropriate design and measures, study implementation at multiple sites, and involvement of multiple service branches (Army, Navy, and Marine Corps). We conclude by emphasizing the need to consider contemporary approaches for evaluating the effectiveness of clinical guidance.