The consideration of post-exercise impact on SCAT3 scores in athletes immediately following a head injury.

METHODS: Symptoms were assessed immediately following completion of a rugby match (median 60 minutes). Players removed from the match for assessment due to a head hit were classified as head injured. Controls completed match without head hit. RESULTS: 209 players (67 female; 33 ± 13 years) participated with 80 experiencing a head injury. Symptom severity was significantly greater in head injured (26.2 ± 17.6) compared with controls (8.9 ± 11.5, P < 0.001). 21% of control players reporting >16 symptom severity, misclassifying them as suspected concussion. There were no significant sex differences. Factor analysis produced four symptom clusters of which Headache was most discriminatory between the head injured (median = 1.7) and controls (median = 0.0). CONCLUSION: These findings demonstrate that exercise and contact during a game affect symptom assessment, increasing the likelihood of misclassifying players with suspected concussion. Factor characterization of symptoms associated with head injury using an exercised comparison group provides more useful discrimination. These results highlight the necessity for objective measures to diagnose concussions outside of symptom self-report.

Determining sensitivity and specificity of the Sport Concussion Assessment Tool 3 (SCAT3) components in university athletes.

OBJECTIVE: To examine the clinical utility of the Sport Concussion Assessment Tool-3 (SCAT3) in university athletes with concussion in the absence and presence of baseline data over time. METHODS: Athletes with concussion (n = 23) and uninjured controls (n = 22) were prospectively evaluated at three time-points (baseline, 3-5 days, 3 weeks post-injury) with the SCAT3 components: (1) Post-Concussion Symptom Scale (PCSS); (2) Standardized Assessment of Concussion (SAC); and (3) modified Balance Error Scoring System (m-BESS). Sensitivity and specificity were calculated using reliable change indices and normative data from 458 athletes who completed baseline testing. RESULTS: The PCSS total symptom score yielded highest sensitivity (47.4-72.2%) and specificity (78.6-91.7%) 3-5 days post-injury, with the SAC and m-BESS demonstrating little discriminative ability when used more than 3 days post-concussion. The utility of the SCAT3 was comparable when baseline or normative data was used for predicting concussion. CONCLUSION: The SCAT is a clinically useful tool for assessing concussion in the absence or presence of baseline data within the first 3-5 days post-injury. Clinical utility of the SCAT3 was driven by symptoms, which remains consistent in the SCAT5. Future research should explore whether additional cognitive elements in the SCAT5 improve utility beyond this timeframe.

Psychometric properties of the standardized assessment of concussion in youth football: Validity, reliability, and demographic factors.

The objective of this study was to determine the psychometrics (reliability, validity) of the original Standardized Assessment of Concussion (SAC) in a youth sample (ages 11 to 13). Demographic factors of race, level of vocabulary knowledge, mother's level of education were also considered. Over 150 youth football athletes completed the SAC and a brief battery of NIH Toolbox cognitive tests as part of a larger study on biomechanical factors in youth sport concussion. This was a within-subjects design (pre-season, post-season assessments), and correlational analysis of convergent and discriminant validity. Between groups analysis based on demographic differences was also employed. The pre-season SAC scores were not different by age; however, SAC scores were statistically different by race: t(155) = 3.162, p = .002, d = .519. Maternal level of education and participant vocabulary scores were related to racial group membership. Convergent and discriminant validity were established compared to NIH Toolbox tests of memory and speed. Pre-post-season tests for 108 participants established marginally acceptable test-retest reliability (ICC = .692). These data support the use of the original SAC in youth football although clinicians must be aware of racial differences in scores.

Rapid sideline performance meets outpatient clinic: Results from a multidisciplinary concussion center registry.

OBJECTIVE: This study investigated the utility of sideline concussion tests, including components of the Sports Concussion Assessment Tool, 3rd Edition (SCAT3) and the King-Devick (K-D), a vision-based test of rapid number naming, in an outpatient, multidisciplinary concussion center treating patients with both sports-related and non-sports related concussions. The ability of these tests to predict clinical outcomes based on the scores at the initial visit was evaluated. METHODS: Scores for components of the SCAT3 and the K-D were fit into regression models accounting for age, gender, and sport/non-sport etiology in order to predict clinical outcome measures including total number of visits to the concussion center, whether the patient reached a SCAT3 symptom severity score≤7, and the total types of referrals each patient received over their course. Patient characteristics, differences between those with sport and non-sport etiologies, and correlations between the tests were also analyzed. RESULTS: Among 426 patients with concussion, SCAT3 total symptom score and symptom severity score at the initial visit predicted each of the clinical outcome variables. K-D score at the initial visit predicted the total number of visits and the total number of referrals. Those with sports-related concussions were younger, had less severely-affected test scores, had fewer visits and types of referrals, and were more likely to have clinical resolution of their concussion and to reach a symptom severity score≤7. CONCLUSIONS: This large-scale study of concussion patients supports the use of sideline concussion tests as part of outpatient concussion assessment, especially the total symptom and symptom severity score portions of the SCAT3 and the K-D. Women in this cohort had higher total symptom and symptom severity scores compared to men. Our data also suggest that those with non-sports-related concussions have longer lasting symptoms than those with sports-related concussions, and that these two groups should perhaps be regarded separately when assessing outcomes and needs in a multidisciplinary setting.

Utility of the Standardized Assessment of Concussion (SAC) to Detect Insufficient Effort in Independent Medical Examinations and Civil Litigation Cases.

OBJECTIVE: The Standardized Assessment of Concussion (SAC) is a standardized mental status screening instrument initially developed for assessment and tracking of concussion symptoms in athletes. The purpose of the current study was to validate the utility of the SAC as an embedded screening measure for insufficient effort in independent medical examinations (IME) and personal injury cases. METHOD: A known-groups design was used to examine the SAC's utility for the detection of insufficient effort in 75 de-identified private IME and civil litigation evaluations. Initial classifications of insufficient effort were made independently of SAC scores, on the basis of having two or more scores falling below established cut-offs on previously validated neuropsychological measures. RESULTS: Results suggest that the total score on the SAC significantly distinguishes effortful respondents from those exhibiting insufficient effort. Empirically derived cut-off scores yielded adequate sensitivity (.62-.95) and negative predictive power (.93-.97). CONCLUSIONS: While optimal cut-off scores depend upon intended use, our data suggest that the SAC is useful as a potential screener for insufficient effort, after which one can employ additional measures to rule out false-positives. Further research is required before cut-off scores can be recommended for clinical use.