Test-Retest Reliability and Reliable Change Estimates for Sensorimotor Concussion Assessments in Healthy Young Adults

Context: Sensorimotor impairments are common sequela following concussion, but recovery following a concussion is often determined through examiner scored clinical testing. There are emerging technologies that provide objective methods to determine physiological impairment after concussion, but the psychometrics of these tools are lacking and must be established for use in clinical practice.

Objective: The purpose of this study was to examine the test-retest reliability and provide reliable change estimates in healthy young adults for outcomes from 3 emerging technologies providing objective assessments of sensorimotor function in healthy young adults.

Design: Test-retest reliability design in a laboratory setting.

Methods: Healthy, young adults completed testing at 2 time points 4 weeks apart on the Bertec Vision Trainer, the Concussion Balance Test (COBALT), and the Neurolign Dx-100 eye-tracking system. We determined test-retest reliability using intraclass correlation coefficients with a 2-way mixed-effects model absolute agreement. Reliable change estimates were calculated for 70%, 80%, 90%, and 95% CIs.

Results: Participants included 30 healthy young adults (age = 25 [5] y, interquartile range = 20-29; range = 18-38; 17% [57%] women). Test-retest reliability for the Bertec Vision Trainer outcomes ranged from 0.56 to 0.88, with 45% of the outcomes being classified as clinically acceptable (>.70 intraclass correlation coefficients ); for COBALT conditions, sway velocity ranged from 0.50 to 0.95, 95% ellipse area ranged from -0.22 to 0.88, and Sway Score ranged from 0.07 to 0.85, with 50% of COBALT metrics being clinically acceptable; and for the Dx-100, outcomes ranged from -0.20 to 0.89, with 52% being clinically acceptable.

Conclusions: Overall, test-retest reliability was moderate-to-good for the Bertec Vision Trainer assessment outcomes but were highly variable for outcomes of postural control using the COBALT and eye-tracking metrics using the Dx-100. This study adds clinically relevant test-retest reliability and reliable change estimates in healthy adults for 3 commercially available sensorimotor assessments.