The Utility of the King-Devick Test in Evaluating Professional Ice Hockey Players With Suspected Concussion.

OBJECTIVE: The purpose of this study was to (1) examine the diagnostic utility of the King-Devick (KD) in professional ice hockey players and (2) determine whether the KD provides unique variance in predicting a diagnosis of concussion when given in combination with the SCAT-5. STUDY DESIGN: Cohort Study. SETTING: Primary care. PATIENTS/PARTICIPANTS: Professional ice hockey players. INDEPENDENT VARIABLES: Diagnosis versus no diagnosis of concussion. MAIN OUTCOME MEASURES: King-Devick and SCAT-5 component scores. METHODS: In part 1, players suspected of having a concussion were evaluated at baseline and acutely with the KD and either the SCAT-3 or the SCAT-5. Players evaluated and not diagnosed with concussion served as active controls. In part 2, a separate group of players suspected of having a concussion was evaluated acutely with both the KD and SCAT-5. RESULTS: In part 1 of this study, 53 concussed players declined in performance on the KD from baseline to acute evaluation, whereas the performance of 76 active controls improved significantly. In part 2 of the study, 75 players were diagnosed with concussion and compared with 80 active controls who were evaluated and not diagnosed with concussion. Concussed players revealed a decline in KD performance from baseline to acute evaluation when compared with controls. However, the KD did not account for significant unique variance in predicting a diagnosis of concussion after accounting for SCAT-5 data. CONCLUSIONS: The KD is useful in differentiating concussed and not concussed athletes acutely, but the KD does not seem to add additional diagnostic value over and above the SCAT-5.