Comparing Postconcussion Sway Balance and Cognitive Test Performance With Preinjury Baseline Identifies a Higher Percentage of Impaired Concussed Athletes Than Comparison With Normative Values

Background: Baseline and postinjury neurocognitive and balance testing assist in the assessment and management of sports-related concussion. We evaluated the utility of comparing postinjury performance on the Sway Medical System Sports+ test battery with individualized baseline data and normative reference data. Hypothesis: Comparisons with baseline data would identify a higher proportion of concussed athletes with impaired scores, as opposed to comparing postinjury performance with normative data. Study Design: Cohort study (Diagnosis); Level of evidence, 3. Methods: Baseline assessments were conducted 1 year apart using the Sway Sports+ battery. Postinjury assessments were conducted within 3 days of concussion and compared with both baseline and normative data using thresholds for 70%, 80%, 90% and 95% CIs. Outcomes were evaluated based on the number of modules within the test battery that surpassed confidence interval thresholds. Results: Both comparison approaches identified a high proportion of concussed athletes as impaired when considering impairment on ≥1 measures (eg, 95% using baseline data, 89% using normative data [70% CI]; 89% baseline, 80% normative [80% CI]; 82% baseline, 70% normative [90% CI]). However, impairment on a single module was common and occurred in both the concussed and the nonconcussed samples. When impairment on ≥2 modules was considered, the baseline comparison method correctly identified a higher proportion of concussed athletes as impaired than the normative comparison method (eg, 82% vs 68% [70% CI]; 67% vs 58% [80% CI]; 52% vs 47% [90% CI]). Impairment on ≥2 modules was uncommon in the control sample but occurred frequently in the concussed sample. Conclusion: Baseline comparisons consistently classified a greater percentage of athletes as concussed than normative comparisons, across all confidence intervals.