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

<p><i>Objectives:</i> 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.<br/><i>Design:</i> Prospective cohort study</br><br/><i>Methods:</i> 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.</br><br/><i>Results:</i> 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) (-1.9 s; z = -5.08; <i>p</i> < 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; <i>p</i> < 0.0001). The overall sensitivity was 0.98, specificity 0.96, and a kappa of κ = 0.94. The positive likelihood ratio was 11.6 and the positive predictive value was 89.0%.</br><br/><i>Conclusions:</i> 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.</br></p>