Concussion Screening Evaluation: BESS vs Sway

Introduction: Rapid evaluation of concussion is important in the pre-hospital setting as an easy test. It is also useful in the ED, as too often little is done for concussed patients. The Balance Error Scoring System (BESS) is the current gold standard for evaluating balance, one of the best predictors of concussion. SWAY, a new gyroscope based iPhone application, is being proposed as a more sensitive and more objective test than BESS. This study will compare Sway to BESS to determine if there is equal efficacy.Method: 74 scholastic and collegiate athletes were administered baseline balance evaluations using Sway. Sway is scored out of 100 points and uses the iPhone’s gyroscope to measure balance while the device is clutched to the tester’s chest with both hands and eyes remain closed. In conjunction with their evaluations, we scored each athlete using BESS. Subjects are assessed one point for the following errors using BESS: Removing hands from the mobile device clutched to their chest; opening the eyes; stepping, stumbling, or falling; remaining out of the test position for five seconds; moving the hip into more than 30° of hip flexion or abduction; or lifting the forefoot or heel. No foam pad was used and subjects used their hands to clutch mobile device to chest instead of keeping hands on hips.Results: The average score of 4.1 on BESS correlates to an average score of 77.1 on Sway. There is moderate to strong correlation between Sway and BESS results that is statistically significant (P\u3c.05). The Sway average score has a STDev of 14.2. The BESS average score has a STDev of 2.9. According to “Normative data for the balance error scoring system: Implications for brain injury evaluation” (G.L. Iverson, M.L. Kaarto, and M.S. Koehle), the 76-90th percentile of individuals ages 20-39 scored 4-6 on BESS.Conclusion: Sway is equally, if not more, sensitive than BESS. While BESS is judged by humans and creates the possibility of human error to occur while evaluating subjects, Sway is completely automated so to minimize human error and give a completely objective score. Sway can replace BESS for rapid balance screening and still maintain clinical accuracy. 1) References “Normative data for the balance error scoring system: Implications for brain injury evaluation” (G.L. Iverson, M.L. Kaarto, and M.S. Koehle