Relationship Between the King-Devick Test and Commonly Used Concussion Tests at Baseline

Context: Comprehensive assessments are recommended to evaluate sport-related concussion (SRC). The degree to which the King-Devick (KD) test adds novel information to an SRC evaluation is unknown. Objective: To describe relationships at baseline among the KD and other SRC assessments and explore whether the KD provides unique information to a multimodal baseline concussion assessment. Design: Cross-sectional study. Setting: Five National Collegiate Athletic Association institutions participating in the Concussion Assessment, Research and Education (CARE) Consortium. Patients or Other Participants: National Collegiate Athletic Association student-athletes (N = 2258, age = 20 +/- 1.5 years, 53.0% male, 68.9% white) in 11 men's and 13 women's sports. Main Outcome Measure(s): Participants completed baseline assessments on the KD and (1) the Symptom Inventory of the Sport Concussion Assessment Tool-3rd edition, (2) the Brief Symptom Inventory-18, (3) the Balance Error Scoring System, (4) the Standardized Assessment of Concussion (SAC), (5) the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) test battery, and (6) the Vestibular/Ocular Motor Screening tool during their first year in CARE. Correlation coefficients between the KD and the 6 other concussion assessments in isolation were determined. Assessments with p magnitude >0.1 were included in a multivariate linear regression analysis to evaluate their relative association with the KD. Results: Scores for SAC concentration, ImPACT visual motor speed, and ImPACT reaction time were correlated with the KD (p = -0.216, -0.276, and 0.164, respectively) and were thus included in the regression model, which explained 16.8% of the variance in baseline KD time (P < .001, Cohen f(2) = 0.20). Better SAC concentration score (beta = -.174, P < .001), ImPACT visual motor speed (beta = -.205, P < .001), and ImPACT reaction time (beta = .056, P .020) were associated with faster baseline KD performance, but the effect sizes were small. Conclusions: Better performance on cognitive measures involving concentration, visual motor speed, and reaction time was weakly associated with better baseline KD performance. Symptoms, psychological distress, balance, and vestibular-oculomotor provocation were unrelated to KD performance at baseline. The findings indicate limited overlap at baseline among the CARE SRC assessments and the KD.