False Positive Rates and Associated Risk Factors on the VOMS and mBESS in U.S. Military Personnel

Abstract

ABSTRACT Context: In 2018, the U.S. military developed the Military Acute Concussion Evaluation-2 (MACE-2) to inform acute evaluation of mTBI. However, researchers have yet to investigate false positive rates for components of the MACE-2 including the Vestibular-Ocular Motor Screen (VOMS) and modified Balance Error Scoring System (mBESS) in military personnel. Objective: To examine factors associated with false positives in VOMS and mBESS in U.S. Army Special Operations Command (USASOC) personnel. Design: Cross-sectional study. Setting: Military medical clinic. Participants: 416 healthy USASOC personnel completed medical history, VOMS, and mBESS evaluations. Main Outcome Measures: False positive rates for the VOMS (2+ on VOMS symptom item, ≥ 5 cm for near point of convergence [NPC] distance) and mBESS (total score >4) were determined using chi-square analyses and independent samples t-tests. Multivariable logistic regressions (LR) with adjusted odds ratios (aOR) were performed to identify risk factors for false positives on VOMS and mBESS. VOMS items false positive rates ranged from 10.6% (smooth pursuits) to 17.5% (NPC). mBESS total score false positive rate was 36.5%. Results: The multivariable LR model supported three significant predictors of VOMS false positives including age (OR= 1.07, 95% CI= 1.02–1.12, p=0.007), migraine (OR=2.49, 95% CI= 1.29–4.81, p=0.007), and motion sickness history (OR=2.46, 95% CI= 1.34–4.50, p=0.004). Results of the multivariable LR model supported only motion sickness history as a significant predictor (OR=2.34, 95% CI= 1.34–4.05, p=0.002) of mBESS false positives. Conclusions: There were low false positive rates across VOMS items, which were associated with age, history of mTBI, migraine, and motion sickness. False positives for the mBESS total score were higher (36.5%) and were only associated with a history of motion sickness. These risk factors for false positives should be considered when administering and interpreting VOMS and mBESS components of the MACE-2 in this population.