The King-Devick test is a valid and reliable tool for assessing sport-related concussion in Australian football: A prospective cohort study

Objectives: Sport-related concussion (SRC) research has focused on impaired oculomotor function. The King-Devick (K-D) test measures oculomotor performance and is reported to identify suboptimal brain function. The use of the K-D test in Australian football (AF), a sport involving body contact and tackling, has not been documented. Therefore, the objective of this study was to determine the test-retest reliability and diagnostic accuracy of the K-D test on a sub-elite AF team. Design: Prospective cohort study Methods: In total, 22 male players (19.6 + 2.3 years) were tested and re-tested on the K-D test. Those suspected of having a SRC secondary to a significant head impact were tested. Randomly selected additional players without SRC were assessed for comparison. Results: There were observable learning effects between the first and second baseline testing (48 vs. 46 s). The ICC for the first and second baseline tests was 0.91. Post-match test times were longer than the baseline times for players with SRC (n = 7) (-1.9s; z = -5.08; p < 0.0001). Players tested with no signs of SRC (n = 13) had an improvement in time when compared with their baseline score (3.0 s; z = -4.38; p <0.0001). The overall sensitivity was 0.98, specificity 0.96, and a kappa of kappa = 0.94. The positive likelihood ratio was 11.6 and the positive predictive value was 89.0%. Conclusions: This study supports the use of the K-D test due to its test-retest reliability, high sensitivity and specificity, and fast and simple use that is ideal for sports medicine professionals to make quick judgement on management and playability. (C) 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.