Reliability and Factors Associated with False Positives on the Vestibular/Ocular Motor Screening (VOMS) Tool in US Military Personnel

Abstract

Abstract Purpose The US Military recently added the Vestibular/Ocular Motor Screening (VOMS) to the Military Acute Concussion Evaluation-2 (MACE-2). However, there are no published data on the VOMS in US military personnel. The purpose of this study was to examine the reliability of the VOMS and factors associated with false positives in healthy US Army Special Operations (USASOC) personnel. Methods 206 healthy USASOC military personnel aged 18–40 completed VOMS between March 2018 – January 2019. Analyses included internal consistency, false-positive rates, intraclass correlation coefficients (ICC), chi-square analyses with odds ratios (OR), and independent samples t-tests. VOMS clinical cut-off scores (2+ on any symptom, >5cm for NPC) were used to determine false positives. Results Reliability for the VOMS symptom items (Cronbach alpha=.98, ICC=.90) and NPC distance (Cronbach’s alpha=.98, ICC=.93) were high. False positive rates ranged from 10.2% (smooth pursuits) to 16.9% (NPC distance). Concussion history was associated with a 2.5 fold increase for one or more VOMS items above cut-offs (p=.01). Participants with at least one VOMS item above cut-offs were deployed nearly 6 months longer on average than those without (p=.04). Conclusion The findings indicate that VOMS is reliable in US military personnel with few false positives. False positives were associated with concussion history and longer deployment history, which should be considered by military medical providers when administering and interpreting VOMS in this population. Moving forward, researchers should examine the stability of VOMS and its ability to identify mTBI in this population.