Concurrent validity of the Berg Balance Scale and the Dynamic Gait Index in people with vestibular dysfunction

BACKGROUND AND PURPOSE: The Berg Balance Scale is a reliable and valid measure that is used to assess characteristics of balance. The Dynamic Gait Index is a relatively new measure that has been used to record dynamic gait tasks in people with vestibular dysfunction. The purpose of the present study was to determine the concurrent validity of the Dynamic Gait Index with the Berg Balance Scale in people with vestibular disorders. METHOD: A retrospective review of the charts of people who met the criteria of having completed both the Berg Balance Scale and the Dynamic Gait Index during their first physiotherapy visit. Seventy patients (19 male, 51 female) were identified through the retrospective review of the charts of people referred for vestibular rehabilitation with varying diagnoses of vestibular and balance dysfunction. All were seen at a tertiary medical centre in an outpatient physiotherapy setting. Their age range was from 14 to 88 years (mean 65 years). RESULTS: Correlation between the scores on the Dynamic Gait Index and the Berg Balance Scale was moderate but significant by use of the Spearman rank order correlation (r = 0.71; p < 01). No difference was found between scores on the Dynamic Gait Index or Berg Balance Scale based on gender or diagnosis. A significant difference was identified on the Berg Balance Scale between older and younger people with vestibular disorders. Using previously established criteria to determine increased risk of falling, the Berg Balance Scale and the Dynamic Gait Index agreed 63% of the time. CONCLUSIONS: The moderate correlation between the Dynamic Gait Index and the Berg Balance Scale establishes the concurrent validity of the Dynamic Gait Index in people with vestibular dysfunction. Both these measures provide valuable information to clinicians about patients' functional balance capabilities. However, the lack of perfect correlation indicates that the tests measure different aspects of balance. The Dynamic Gait Index appears to be a more sensitive assessment tool in identifying people with vestibular disorders who are at increased risk for falling, based on currently published criteria.