Jacob E. Resch

ImPact Test-Retest Reliability: Reliably Unreliable?

CONTEXT Computerized neuropsychological testing is commonly used in the assessment and management of sport-related concussion. Even though computerized testing is widespread, psychometric evidence for test-retest reliability is somewhat limited. Additional evidence for test-retest reliability is needed to optimize clinical decision making after concussion. OBJECTIVE To document test-retest reliability for a commercially available computerized neuropsychological test battery (ImPACT) using 2 different clinically relevant time intervals. DESIGN Cross-sectional study. SETTING Two research laboratories. PATIENTS OR OTHER PARTICIPANTS Group 1 (n = 46) consisted of 25 men and 21 women (age = 22.4 ± 1.89 years). Group 2 (n = 45) consisted of 17 men and 28 women (age = 20.9 ± 1.72 years). INTERVENTION(S) Both groups completed ImPACT forms 1, 2, and 3, which were delivered sequentially either at 1-week intervals (group 1) or at baseline, day 45, and day 50 (group 2). Group 2 also completed the Green Word Memory Test (WMT) as a measure of effort. MAIN OUTCOME MEASURES Intraclass correlation coefficients (ICCs) were calculated for the composite scores of ImPACT between time points. Repeated-measures analysis of variance was used to evaluate changes in ImPACT and WMT results over time. RESULTS The ICC values for group 1 ranged from 0.26 to 0.88 for the 4 ImPACT composite scores. The ICC values for group 2 ranged from 0.37 to 0.76. In group 1, ImPACT classified 37.0% and 46.0% of healthy participants as impaired at time points 2 and 3, respectively. In group 2, ImPACT classified 22.2% and 28.9% of healthy participants as impaired at time points 2 and 3, respectively. CONCLUSIONS We found variable test-retest reliability for ImPACT metrics. Visual motor speed and reaction time demonstrated greater reliability than verbal and visual memory. Our current data support a multifaceted approach to concussion assessment using clinical examinations, symptom reports, cognitive testing, and balance assessment.

Computerized neurocognitive testing in the management of sport-related concussion: an update.

Since the late nineties, computerized neurocognitive testing has become a central component of sport-related concussion (SRC) management at all levels of sport. In 2005, a review of the available evidence on the psychometric properties of four computerized neuropsychological test batteries concluded that the tests did not possess the necessary criteria to warrant clinical application. Since the publication of that review, several more computerized neurocognitive tests have entered the market place. The purpose of this review is to summarize the body of published studies on psychometric properties and clinical utility of computerized neurocognitive tests available for use in the assessment of SRC. A review of the literature from 2005 to 2013 was conducted to gather evidence of test-retest reliability and clinical validity of these instruments. Reviewed articles included both prospective and retrospective studies of primarily sport-based adult and pediatric samples. Summaries are provided regarding the available evidence of reliability and validity for the most commonly used computerized neurocognitive tests in sports settings.

The sensitivity and specificity of clinical measures of sport concussion: three tests are better than one

Context A battery of clinical measures of neurocognition, balance and symptoms has been recommended for the management of sport concussion (SC) but is based on variable evidence. Objective To examine the sensitivity and specificity of a battery of tests to assess SC in college athletes. Design Cross-sectional. Setting Research laboratory. Patients or other participants Division 1 athletes diagnosed with a SC (n=40) who were 20.2±1.60 years of age and 180.5±11.12 cm tall and healthy athletes (n=40) who were 19.0±0.93 years of age and 179.1±11.39 cm tall were enrolled. Intervention(s) Participants were administered Immediate Postconcussion Assessment and Cognitive Test (ImPACT), the Sensory Organization Test (SOT) and the Revised Head Injury Scale (HIS-r) prior to and up to 24 h following injury between the 2004 and 2014 sport seasons. Sensitivity and specificity were calculated using predictive discriminant analyses (PDA) and clinical interpretation guidelines. Main outcome measures Outcome measures included baseline and postinjury ImPACT, SOT and HIS-r composite scores. Results Using PDA, each clinical measures sensitivity ranged from 55.0% to 77.5% and specificity ranged from 52.5% to 100%. The test battery possessed a sensitivity and specificity of 80.0% and 100%, respectively. Using clinical interpretation guidelines, sensitivity ranged from 55% to 97.5% individually, and 100% when combined. Conclusions Our results support a multidimensional approach to assess SC in college athletes which correctly identified 80–100% of concussed participants as injured. When each test was evaluated separately, up to 47.5% of our sample was misclassified. Caution is warranted when using singular measures to manage SC.

Preliminary Evidence of Equivalence of Alternate Forms of the ImPACT

The ImPACT (Immediate Postconcussion Assessment and Cognitive Testing) is a computerized neurocognitive test used to assist in the management of sport concussion management. A number of studies have documented the reliability and sensitivity of the ImPACT, but no studies have examined the equivalence of the ImPACT’s alternate forms. The objective of our study was to determine the equivalence of the ImPACT’s five alternate forms. Participants were administered alternate forms of ImPACT based on clinically relevant time frame derived from an extensive sports concussion database. Participants completed a baseline assessment followed by various combinations of the remaining alternate forms at 45 and 50 days. Inferential Confidence Intervals were calculated for each composite score for all alternate forms. We found non-equivalence between ImPACT form 1 and forms 2, 3, and 4 on the Verbal Memory and between forms 2 and 4. ImPACT forms 1 and 3 were not equivalent on the Visual Memory Composite. Finally, ImPACT forms 3 and 4 were not equivalent on the Visual Motor Speed and Reaction Time Composites. Alternate form equivalence is necessary to minimize measurement error and optimize clinical decision making. Clinicians using the ImPACT should consider non-equivalence of some forms on certain Composites when interpreting ImPACT following sports concussion.

A Preliminary Formula to Predict Timing of Symptom Resolution for Collegiate Athletes Diagnosed With Sport Concussion

CONTEXT Symptom presentation and recovery after sport concussion (SC) are variable. Empirically based models documenting typical symptom duration would assist health care providers in managing return to play after SC. OBJECTIVE To develop a prediction model for SC symptom duration. DESIGN Cross-sectional study. SETTING Two National Collegiate Athletic Association Division I university laboratories. PATIENTS OR OTHER PARTICIPANTS Seventy-six (51 male and 25 female) concussed athletes with an average age of 19.5 ± 1.65 years who were evaluated within 24 hours of diagnosis. INTERVENTION(S) Participants completed the Revised Head Injury Scale (HIS-r), Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), and Sensory Organization Test within 24 hours of SC diagnosis. MAIN OUTCOME MEASURE(S) A stepwise multivariate regression incorporating ImPACT and Sensory Organization Test composites and HIS-r symptom severity-duration was used to predict the number of days athletes reported symptoms after SC. The resulting regression formula was cross-validated using the Stine cross-validation coefficient. RESULTS The final formula consisted of the HIS-rs self-reported neck pain, drowsiness, tingling, and nervousness duration and ImPACT total symptom severity (R = 0.62, R(2) = 39%, R(2)(adj) = 34.2%, P < .001). Approximately 29% (R(2)(cv) = 29%) of the variance associated with total days symptomatic after SC was explained by our preliminary formula when cross-validated. The current formula correctly identified 76% of participants who recovered within 10 days of injury. CONCLUSIONS Our results suggest that self-reported duration of 4 symptoms during the initial 24 hours after injury along with total symptom severity as measured by ImPACT accounted for a considerable amount of variance associated with days symptomatic after SC in collegiate athletes. Until the formula is cross-validated in a college-aged sample, caution is warranted in using it clinically.

Exertional heat illness in American football players: when is the risk greatest?

CONTEXT Knowledge about the specific environmental and practice risks to participants in American intercollegiate football during preseason practices is limited. Identifying risks may mitigate occurrences of exertional heat illness (EHI). OBJECTIVE To evaluate the associations among preseason practice day, session number, and wet bulb globe temperature (WBGT) and the incidence of EHI. DESIGN Descriptive epidemiology study. SETTING Sixty colleges and universities representing 5 geographic regions of the United States. PATIENTS OR OTHER PARTICIPANTS National Collegiate Athletic Association football players. MAIN OUTCOME MEASURE(S) Data related to preseason practice day, session number, and WBGT. We measured WBGT every 15 minutes during the practice sessions and used the mean WBGT from each session in the analysis. We recorded the incidence of EHIs and calculated the athlete-exposures (AEs). RESULTS A total of 553 EHI cases and 365 810 AEs were reported for an overall EHI rate of 1.52/1000 AEs (95% confidence interval [CI] = 1.42, 1.68). Approximately 74% (n = 407) of the reported EHI cases were exertional heat cramps (incidence rate = 1.14/1000 AEs; 95% CI = 1.03, 1.25), and about 26% (n = 146) were a combination of exertional heat syncope and heat exhaustion (incidence rate = 0.40/1000 AEs; 95% CI = 0.35, 0.48). The highest rate of EHI occurred during the first 14 days of the preseason period, and the greatest risk was during the first 7 days. The risk of EHI increased substantially when the WBGT was 82.0°F (27.8°C) or greater. CONCLUSIONS We found an increased rate of EHI during the first 14 days of practice, especially during the first 7 days. When the WBGT was greater than 82.0°F (27.8°C), the rate of EHI increased. Sports medicine personnel should take all necessary preventive measures to reduce the EHI risk during the first 14 days of practice and when the environmental conditions are greater than 82.0°F (27.8°C) WBGT.

Sport Concussion and the Female Athlete

Sport concussion (SC) has emerged as a major health concern in the medical community and general public owing to increased research and media attention, which has primarily focused on male athletes. Female athletes have an equal, if not increased, susceptibility to SC. An ever-growing body of research continues to compare male and female athletes in terms of SC before and after an injury. Clinicians must be cognizant of this literature to make evidence-based clinical decision when providing care to female athletes and discern between dated and/or unsupported claims in terms of SC.

The Acute Management of Sport Concussion in Pediatric Athletes

During the past two decades the focus on sport concussion has increased significantly. Young athletes represent the most vulnerable population to sustain a sport concussion yet receive the least amount of attention. Specifically, young athletes who sustain a sport concussion can go unrecognized and continue to participate in sport putting them at an increased risk for a more significant injury. The purpose of this review is to provide a clinical framework for the evaluation and management of sport concussion. In addition, this review provides considerations for health care professionals in regard to clinical measures and follow-up strategies during the acute phase following concussion in young concussed athletes following injury.

The test-retest reliability of three computerized neurocognitive tests used in the assessment of sport concussion

Computerized neurocognitive tests (CNTs) are widely used at all competitive levels of sport to assess sport concussion (SC). Whereas there are multiple CNTs available, little is known about how some of the most popular platforms compare. The purpose of this study was to investigate the test-retest reliability of the Automated Neuropsychological Assessment Metrics (ANAM), Concussion Vital Signs (CVS) and the Immediate Postconcussion and Cognitive Testing battery (ImPACT) using clinically relevant time points in healthy college-age participants. Participants were healthy college-age students (N=128) randomly assigned into one of three groups which were administered ANAM, CVS, or ImPACT at Days 1, 45 and 50. Intraclass correlation coefficients (ICCs) and Pearson correlations were used to assess reliability of the various CNT scores and subtest scores between time points. Participants were tested approximately 47.1±2.75days after time point 1 and approximately 7.0±2.45days after time point 2. ICC values ranged from 0.18 (Procedural Reaction Time) to 0.53 (Mathematical Processing and Simple Reaction Time 1) for ANAM, 0.14 (Continuous Performance Test) to 0.85 (Reaction Time) for CVS, and 0.19 (Verbal Memory) to 0.89 (Visual Motor Speed) for ImPACT. Significant improvements (p<0.05) across time were observed for (7/10) CNS Vital Signs composite scores, but no additional significant changes in performance were observed for the remaining CNTs. Overall, weak to strong reliability coefficients for ANAM, CVS, and ImPACT were observed when using clinically relevant time points of repeated administration.

Reliability of a Novel Approach for Quadriceps Motor Point Assessment

Introduction: We studied the ability of clinicians to identify quadriceps motor points using a transcutaneous electrical stimulation unit (TENS). Methods: Twenty‐two certified athletic trainers and 1 expert‐rater identified the 7 motor points of the quadriceps at 2 time‐points separated by 1 week. The difference was calculated between where each participant and the expert‐rater identified each motor point using an x–y coordinate system. Bland–Altman plots were used to compare differences between 2 testing sessions. Results: No differences were observed between participants and the expert‐rater for motor point location. The smallest variability in the limits of agreements were observed in the distal vastus medialis oblique (–1.89 to 1.86 cm) and proximal vastus lateralis (–1.61 to 2.35 cm). Discussion: Our results suggest the utilization of a TENS unit may be 1 way to identify quadriceps motor points to improve electrical stimulation applications. The smallest limits of agreement were over the most common quadriceps electrical stimulation electrode positions. Muscle Nerve 57: E1–E7, 2018