Benjamin L. Brett

The influence of validity criteria on Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) test–retest reliability among high school athletes

ABSTRACT Objective: Research findings to date on the stability of Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) Composite scores have been inconsistent, requiring further investigation. The use of test validity criteria across these studies also has been inconsistent. Using multiple measures of stability, we examined test–retest reliability of repeated ImPACT baseline assessments in high school athletes across various validity criteria reported in previous studies. Method: A total of 1146 high school athletes completed baseline cognitive testing using the online ImPACT test battery at two time periods of approximately two-year intervals. No participant sustained a concussion between assessments. Five forms of validity criteria used in previous test–retest studies were applied to the data, and differences in reliability were compared. Results: Intraclass correlation coefficients (ICCs) ranged in composite scores from .47 (95% confidence interval, CI [.38, .54]) to .83 (95% CI [.81, .85]) and showed little change across a two-year interval for all five sets of validity criteria. Regression based methods (RBMs) examining the test–retest stability demonstrated a lack of significant change in composite scores across the two-year interval for all forms of validity criteria, with no cases falling outside the expected range of 90% confidence intervals. Conclusion: The application of more stringent validity criteria does not alter test–retest reliability, nor does it account for some of the variation observed across previously performed studies. As such, use of the ImPACT manual validity criteria should be utilized in the determination of test validity and in the individualized approach to concussion management. Potential future efforts to improve test–retest reliability are discussed.

Comparison of Neurocognitive Performance in Contact and Noncontact Nonconcussed High School Athletes Across a Two-Year Interval

ABSTRACT Investigating short-term effects of subconcussive impacts on neurocognitive functioning, we employed a repeated measures multivariate model and regression-based measure to examine neurocognitive changes in 771 contact and noncontact high school athletes over a two-year period. Results reveal significant changes in Visual Motor Speed for both groups over a two-year period, with small effect sizes. According to regression-based measures, differences in contact sport athletes’ expected Time 2 performances were significant for Visual Motor Speed, also with minimal effects. Results do not conclusively implicate subconcussive hits as the offending factor in differences observed, with gender and sport-type possibly contributing to the small effects.

The role of family and personal psychiatric history in postconcussion syndrome following sport-related concussion: a story of compounding risk

OBJECTIVE Sport-related concussion (SRC) has become a major public health concern. Prolonged recovery after SRC, named postconcussion syndrome (PCS), has been associated with several biopsychosocial factors, yet the role of both family and personal psychiatric histories requires investigation. In a cohort of concussed high school athletes, the authors examined the role(s) of family and personal psychiatric histories in the risk of developing PCS. METHODS A retrospective cohort study of 154 high school athletes with complete documentation of postconcussion symptom resolution or persistence at 6 weeks was conducted. PCS was defined as 3 or more symptoms present 6 weeks after SRC. Three groups were defined: 1) positive family psychiatric history and personal psychiatric history (FPH/PPH), 2) positive FPH only, and 3) negative family and personal psychiatric histories (controls). Three bivariate regression analyses were conducted: FPH/PPH to controls, FPH only to controls, and FPH/PPH to FPH. Post hoc bivariate regression analyses examined specific FPH pathologies and PCS. RESULTS Athletes with FPH/PPH compared with controls had an increased risk of PCS (χ2 = 8.90, p = 0.018; OR 5.06, 95% CI 1.71-14.99). Athletes with FPH only compared with controls also had an increased risk of PCS (χ2 = 6.04, p = 0.03; OR 2.52, 95% CI 1.20-5.30). Comparing athletes with FPH/PPH to athletes with FPH only, no added PCS risk was noted (χ2 = 1.64, p = 0.247; OR 2.01, 95% CI 0.68-5.94). Among various FPH diagnoses, anxiety (χ2 = 7.48, p = 0.021; OR 2.99, 95% CI 1.36-6.49) and bipolar disorder (χ2 = 5.13, p = 0.036; OR 2.74, 95% CI 1.14-6.67) were significantly associated with the presence of PCS. CONCLUSIONS Concussed high school athletes with FPH/PPH were greater than 5 times more likely to develop PCS than controls. Athletes with only FPH were over 2.5 times more likely to develop PCS than controls. Those with an FPH of anxiety or bipolar disorder are specifically at increased risk of PCS. These results suggest that not only are athletes with FPH/PPH at risk for slower recovery after SRC, but those with an FPH only-especially anxiety or bipolar disorder-may also be at risk. Overall, this study supports taking a detailed FPH and PPH in the management of SRC.

The Relationship Between Prior Concussions and Depression Is Modified by Somatic Symptomatology in Retired NFL Athletes

A positive relationship between sport-related concussion (SRC) history and depressive symptoms in retired National Football League (NFL) athletes has been observed, with self-rated physical functioning identified as a confounding factor. The authors examined the influence of somatic symptom endorsement on the relationship between SRC history and self-reported depressive symptom severity in retired NFL athletes. Forty-three former NFL athletes completed self-report inventories of depression (with the Beck Depression Inventory II) and somatic symptoms (with the adjusted Patient Health Questionnaire-15). A moderation analysis examined the influence of somatic symptoms on the relationship between SRC history and depressive symptom severity. SRC history and somatic symptoms accounted for a significant amount of depressive symptomology. SRC history was not significantly associated with depressive symptom severity at low levels of somatic symptoms but was significant at the mean and high levels. The effect of somatic symptoms on depressive symptoms was nearly twice that of SRC history. The relationship between SRC and depression is complex, and treatment of depression in retired athletes should address comorbid somatic symptoms.

Two-year Test–Retest Reliability in High School Athletes Using the Four- and Two-Factor ImPACT Composite Structures: The Effects of Learning Disorders and Headache/Migraine Treatment History

Objective This study examined the test-retest reliability of the four- and two-factor structures (i.e., Memory and Speed) of ImPACT over a 2-year interval across multiple groups with premorbid conditions, including those with a history of special education or learning disorders (LD; n = 114), treatment history for headache/migraine (n = 81), and a control group (n = 792). Methods Nine hundred and eighty seven high school athletes completed baseline testing using online ImPACT across a 2-year interval. Paired-samples t-tests documented improvement from initial to follow-up assessments. Test stability was examined using Regression-based measures (RBM) and Reliable change indices (RCI). Reliability was examined using intraclass correlation coefficients (ICC). Results Significant improvement on all four composites were observed for the control group over a 2-year interval; whereas significant differences were observed only on Visual Motor Speed for the LD and headache/migraine treatment history groups. ICCs ranges were similar across groups and greater or comparable reliability was observed for the two-factor structure on Memory (0.67-0.73) and Speed (0.76-0.78) composites. RCIs and RBMs demonstrated stability for the four- and two-factor structures, with few cases falling outside the range of expected change within a healthy sample at the 90% and 95% CIs. Conclusion Typical practices of obtaining new baselines every 2 years in the high school population can be applied to athletes with a history of special education or LD and headache/migraine treatment. The two-factor structure has potential to increase test-retest reliability. Further research regarding clinical utility is needed.

Risk Factors Associated With Sustaining a Sport-related Concussion: An Initial Synthesis Study of 12,320 Student-Athletes

Objective The empirical identification of risk factors associated with sport-related concussion (SRC) may improve the management of student-athletes. The current study attempted to identify and quantify bio-cognitive risk factors associated with sustaining a SRC. Methods Cross-sectional ambispective study; level of evidence, 3. Neurocognitive testing of 12,320 middle school, high school and collegiate athletes was completed at preseason baseline and post-SRC. Univariate and multivariable logistic regressions were used to determine which pre-injury variables accurately predicted the occurrence of SRC. A quantitative risk score for each variable was developed. Results Five of 13 variables maintained significance in the multivariable model with the associated weighted point scores: SRC history (21), prior headache treatment (6), contact sport (5), youth level of play (7), and history of ADHD/LD (2). Six stratified groups were formed based on probability of SRC, which produced an area under the curve (AUC) of 0.71 (95% CI 0.69-0.72, p < .001). Though the model was a significant predictor of SRC (X2 = 1,112.75, p < .001), the effect size was small and accounted for only 16% of the overall variance. Conclusions An initial aggregate model of weighted bio-cognitive factors associated with increased odds of sustaining a SRC was developed. Previously validated factors were confirmed, yet a large source of variance remained unexplained. These findings emphasize the need to expand the host factors studied when assessing SRC risk, and that the existing, empirically based bio-cognitive factors do not adequately quantify the risk of SRC.

Team versus individual sport participation as a modifying factor in the development of post-concussion syndrome after first concussion: A pilot study

ABSTRACT Identification of modifying factors that influence the development of post-concussion syndrome (PCS) following sport-related concussion (SRC) has drawn considerable interest. In this pilot study, we investigate the effect of team vs. individual sport participation on the development of PCS in a sample of 136 high school and college student-athletes. Controlling for several confounding variables, we employed a binary logistic regression and chi-squared test. Results of this pilot study indicate that participation in team versus individual sport is not a significant factor in the development of PCS. The identification of other forms of protective mechanisms is discussed.