Minimum Detectable Change of the Berg Balance Scale and Dynamic Gait Index in Older Persons at Risk for Falling

BACKGROUND: The Berg Balance Scale (BBS) and the Dynamic Gait Index (DGI) are often the central components of the physical therapy evaluation to identify older adults at risk of falling. PURPOSE: The purpose of this study was to use the standard error of measurement to investigate the minimal detectable change associated with these clinical instruments. METHODS: A sample of 42 community dwellers (older than 65 years) with a history of falls or near falls was evaluated with the BBS and DGI. Evaluations were videotaped and later rescored by 2 experienced physical therapists. RESULTS: The mean initial BBS was 39 points (SD = 8.9, range 17-53). Rescored mean value was 40 points (SD = 8.8, range 19-55). The DGI mean initial value was 12.9 (SD = 4.5, range 3-21), and the rescored mean was 12.7 (SD = 4.6, range 4-22). MDC95% values were 6.5 BBS and 2.9 DGI points, respectively. CONCLUSION: These results suggest that a change of 6.5 point in the BBS and 2.9 points in the DGI is necessary to be 95% confident that genuine change in function has occurred between 2 assessments. This information is important for assessing and monitoring progress and guiding treatment for community dwellers at high risk of falling.