Despite the clinical utility of baseline comparisons during concussion assessments, little evidence exists on longterm test-retest reliability of baseline tests in youth athletes. Sex differences in baseline performance have been shown to be inconsistent in youth athletes, warranting further research. In a study led by, PISC Postdoctoral Research Fellow, Abigail Bretzin, PhD, ATC, along with Morgan Anderson, Ryan Moran, PhD, and Tracey Covassin, PhD, sex differences, prevalence of false-positive scores, and long-term test-retest reliability of the King-Devick (KD) test are examined.
Healthy youth athletes completed the KD test prior to the Spring 2016 and Fall 2017 seasons. Two-way random-effects intraclass correlation coefficients (ICCs) were utilized to determine test-retest reliability. A mixed between-within ANOVA with post-hoc t-tests were used to identify the interaction between sex and season, and frequencies were used to determine abnormal test score prevalence.
The KD test demonstrated good test-retest reliability, with 11.8% of youth athletes having clinically meaningful improvements between Season 1 to Season 2. There were significantly greater improvements between seasons in male youth athletes compared to female youth athletes. However, 33–35% of youth athletes displayed abnormal test scores in Season 2 relative to Season 1. The KD test demonstrated good reliability and only a small percentage had clinically meaningful changes.