Abstract
BACKGROUND: The King-Devick (KD) test is a timed rapid number naming test used for the acute diagnosis of concussion. HYPOTHESIS: The KD test will be more sensitive, but less specific, than other commonly used objective tests for concussion. STUDY DESIGN: Case-control study. LEVEL OF EVIDENCE: Level 4. METHODS: National Collegiate Athletic Association Division I college athletes completed baseline testing for the KD. When an athlete presented acutely with suspected concussion from July 1, 2020 to December 31, 2022 (sideline/within 48 hours) the test was repeated. If a concussion was diagnosed, a control matched on comorbid conditions, sex/gender, team, season, and baseline test time was identified to test. RESULTS: Baseline and postinjury data were collected for 97 concussed and 97 matched control athletes. In total, 44% of concussions occurred in female athletes, with most concussion occurring in football 37 (38%), women's volleyball 14 (14%), and softball 6 (6%). The KD test had fair test-retest reliability at 0.72 (95% CI, 0.61-0.80). The sensitivity and specificity of the test for any increase in time compared with baseline was 81% and 56%, with a positive predictive value of 65% and negative predictive value of 75%. The AUC was also fair at 0.75 (0.68-0.82). There was no significant difference in accuracy of the KD taken at different times points (immediate, 2-8 hours, 8-24 hours, 24-48 hours). CONCLUSION: The KD is more sensitive, but less specific, than other commonly used objective tests for concussion. Understanding the psychometric properties of the KD can help with the diagnosis of concussion. CLINICAL RELEVANCE: The KD may be a good initial screening tool to prompt further evaluation or allow return to play without further evaluation. Further study in other populations is needed.