Reliability of the dynamic gait index in individuals with multiple sclerosis

Objectives: To determine if the Dynamic Gait Index (DGI) is a reliable toot for assessing balance in people with multiple sclerosis (MS) and to determine the validity of the DGI by using, the 6.1-m timed walk. Design: Instrument reliability test: physical therapists viewed a videotape of 10 subjects with MS performing the DGI and scored their gait by using DGI criteria. Two weeks after the first session, therapists' viewed the videotape again and scored subjects' gait to establish interrater reliability. Setting: Hospital-based outpatient rehabilitation clinic. Participants: Eleven physical therapists and 10 people with MS. Interventions: Not applicable. Main Outcome Measures: Total DGI scores and each of the 8 DGI items were compared between and within raters (physical therapists). Time to walk 6.1-m was compared with the total DGI score to examine concurrent validity. Results: Interrater reliability for total DGI scores was .983, with each of the 8 items ranging from .910 to .976 (intraclass correlation coefficient, P < .05). Intrarater reliability for total DGI scores ranged between .760 and .986 (Pearson bivariate analysis, P < .05). An inverse relationship of -.801 (Pearson bivariate analysis, P < .01) existed between the total DGI scores and the 6.1-m walk. Conclusions: The DGI is a reliable functional assessment tool that correlated inversely with timed walk, showing its concurrent validity.