A Comparative Meta-Analysis of the Effects of Concussion on a Computerized Neurocognitive Test and Self-Reported Symptoms.

CONTEXT: Meta-analyses examining construct-specific cognitive impairment concurrently with self-reported symptoms postconcussion are sparse. OBJECTIVE: To review the literature on the effects of concussion on construct-specific neurocognitive declines and to compare them with self-reported symptoms before 1 week and between 1 and 3 weeks postconcussion. DATA SOURCES: Relevant studies in PubMed, CINAHL, and PsycINFO published from January 1, 1999 through November 30, 2015. STUDY SELECTION: Studies were included if participants completed the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) before and after concussion and if test performance and Postconcussion Symptom Scale (PCSS) scores were reported at both times. DATA EXTRACTION: After reviewing the full texts, we extracted data from 17 studies consisting of 29 independent samples; therefore, this meta-analysis consisted of 1777 unique participants. DATA SYNTHESIS: The Hedges g effect size (ES) was estimated. A random-effects or fixed-effects model was used based on heterogeneity findings. When heterogeneity was present, we used meta-regression to assess unexplained between-studies variance. Within the first week of injury, the ESs were small to moderate for cognitive declines, ranging from -0.43 (95% confidence interval [CI] = -0.52, -0.35) to -0.67 (95% CI = -0.77, -0.58), and large for the PCSS score (Hedges g = -0.81; 95% CI = -0.91, -0.71). After 1 week, the ESs for cognitive declines (Hedges g range = -0.25 [95% CI = -0.35, -0.15] to -0.37 [95% CI = -0.55, -0.19]) and PCSS score (Hedges g = -0.38; 95% CI = -0.53, -0.22) were also small. Within 2 weeks of injury, PCSS score and time since injury weakly moderated the cognitive ES. CONCLUSIONS: When a neurocognitive test was administered within 1 week of injury, the ES was larger for self-reported symptoms than for ImPACT scores generated at the same session. After 1 week of injury, the ESs for ImPACT and PCSS scores were comparable. If the athlete reports symptoms within 1 week of injury, administering a cognitive test does not appear to offer additional information to the clinician. However, if the athlete does not report symptoms postconcussion, cognitive testing may inform the clinical management of the injury.

Cumulative Effects of Concussion History on Baseline Computerized Neurocognitive Test Scores: Systematic Review and Meta-analysis.

CONTEXT: It is unclear whether individuals with a history of single or multiple clinically recovered concussions exhibit worse cognitive performance on baseline testing compared with individuals with no concussion history. OBJECTIVE: To analyze the effects of concussion history on baseline neurocognitive performance using a computerized neurocognitive test. DATA SOURCES: PubMed, CINAHL, and psycINFO were searched in November 2015. The search was supplemented by a hand search of references. STUDY SELECTION: Studies were included if participants completed the Immediate Post-concussion Assessment and Cognitive Test (ImPACT) at baseline (ie, preseason) and if performance was stratified by previous history of single or multiple concussions. STUDY DESIGN: Systematic review and meta-analysis. LEVEL OF EVIDENCE: Level 2. DATA EXTRACTION: Sample size, demographic characteristics of participants, as well as performance of participants on verbal memory, visual memory, visual-motor processing speed, and reaction time were extracted from each study. RESULTS: A random-effects pooled meta-analysis revealed that, with the exception of worsened visual memory for those with 1 previous concussion (Hedges g = 0.10), no differences were observed between participants with 1 or multiple concussions compared with participants without previous concussions. CONCLUSION: With the exception of decreased visual memory based on history of 1 concussion, history of 1 or multiple concussions was not associated with worse baseline cognitive performance.

Validity of the Immediate Post Concussion Assessment and Cognitive Testing (ImPACT).

BACKGROUND: The immediate post concussion assessment and cognitive testing (ImPACT) is the most widely used concussion assessment tool. Despite its popularity, it is unclear if validation studies for the ImPACT test covered all aspects of validity to support its widespread use in research and clinical practice. OBJECTIVE: The purpose of this report is to review literature surrounding the validity and the utility of the ImPACT test. DATA SOURCES AND APPRAISAL: A systematic review of relevant studies in PubMed, CINAHL, and PsycINFO was carried out. Studies were evaluated using the STROBE (strengthening the reporting of observational studies in epidemiology) or the STARD (standards for reporting of diagnostic accuracy) criteria. RESULTS: The literature search yielded 5968 studies. Sixty-nine studies met the inclusion criteria and were included in the qualitative review. Although the convergent validity of ImPACT was supported, evidence of discriminant and predictive validity, diagnostic accuracy and responsiveness was inconclusive. The utility of the ImPACT test after acute symptom resolution was sparse. The review found many factors influenced the validity and utility of ImPACT scores. CONCLUSION: Clinicians must consider the benefit of ImPACT testing for their patients on a case-by-case scenario and must take the psychometric properties of the test into account when interpreting results.

Measurement Error in the Immediate Postconcussion Assessment and Cognitive Testing (ImPACT): Systematic Review.

OBJECTIVE: To review the literature on the reliability of the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT). DESIGN: Systematic review of the relevant literature in PubMed, CINAHL, and PSYCHINFO. Studies were evaluated using the STROBE instrument and custom developed items. RESULTS: Search yielded 5 943 articles. Ten studies met the inclusion criteria and were reviewed. With the exception of processing speed, all composite scores consistently exhibited poor to moderate reliability (ie, intraclass correlation coefficient <0.80). When considering 2 time points, participants who were misclassified as experiencing a "reliable change" in any score ranged between 5% and 26% for verbal memory, 2.2% and 19.6% for visual memory, 4% and 24% for processing speed, and 4% and 23.2% for reaction time. CONCLUSIONS: The Pearson r correlation coefficient and average measures intraclass correlation coefficient may be inappropriately utilized to examine the reliability of ImPACT scores. Given the poor to moderate reliability of most ImPACT scores, clinicians should be cautious when ImPACT is used as a criterion for medical clearance to return to play after concussion. Because of its widespread use in concussion-related clinical research, researchers must exercise due diligence when utilizing ImPACT to evaluate outcomes after concussion or to validate other outcome measures.