Baseline King-Devick scores for adults are not generalizable; however, age and education influence scores

To establish normative values for the King-Devick (K-D) test to be used as a reference for determining impairment related to concussion when individual baseline scores are lacking.

Baseline K-D scores were collected for 243 participants aged 18-86.

The mean age of subjects was 40.46; range 18-86 years. The mean time was 42.2 seconds; 26.19-75.96 seconds. There was a relationship (r = 0.376) between K-D score and age; scores increased (worsened) with age. There was also a relationship between score and education with scores decreasing as education increased (r = -0.194; p = 0.002). The K-D score was not influenced by sex or concussion history. A regression equation using education and age to predict K-D time explained 0.418 of the variance in K-D test time.

Although this research established a relationship between K-D score and age and education, the range in scores was too broad to establish normative values. In the absence of a baseline score, the use of a regression equation considering age and education level may provide some indication of expected score. However, the most reliable use of the test as a screen for impairment following concussion involves the use of a baseline test.