Objective: This study aimed to identify the Balance Error Scoring System's (BESS) intraclass reliability in a cohort of patients with prolonged symptoms using variance component analysis and intraclass correlation coefficient (ICC).
Setting: Outpatient sports medicine/concussion clinic.
Participants: A total of 241 paediatric and 102 adult patients with symptoms lasting longer than 10 days.
Interventions: BESS testing.
Design: Retrospective review.
Main outcome measures: Percent variance for each BESS component and intraclass reliability. A five-component model (including all components except for firm double-leg) and a four- component model (including all components except for firm and foam doubleleg) were also performed to compare ICC values.
Results: The largest source of variance came from stance (41.1%). The BESS components firm single (25.5%) and foam tandem (27.5%) stances accounted for the largest percentages of variance, while firm double (1.1%) and foam double (6.9%) accounted for the smallest percentages. The ICC for all patients was 0.800, and increased both if the firm double stance was excluded, or if both double-leg stances were excluded.
Conclusion: BESS reliability appears to be high in a concussed cohort, regardless of age. Removing the two double-leg stance portions increases the ICC of the test without failing to identify balance deficits.
Keywords: Mild traumatic brain injury; components; concussion; post-concussion syndrome; reliability; stance.