Reliability and validity of the dynamic gait index in persons with chronic stroke

Objective: To establish the test-retest and interrater reliability as well as the concurrent construct validity of the Dynamic Gait Index (DGI) as a measure for dynamic balance in people with chronic stroke. Design: Cohort study. Setting: Day hospital and ambulatory care at a rehabilitation center. Participants: A consecutive sample of 25 participants, at least 3 months poststroke and able to walk at least 10m with or without a walking aid, participated in the study. Two independent raters rated performances on the DGI. Interventions: Not applicable. Main Outcome Measures: The DGI was administered in 2 testing sessions 3 days apart. In the second session, the participants were rated by 2 raters. Intraclass correlation coefficients (ICCs), model 2,L and the Bland and Altman method were used to analyze total scores and item scores. Concurrent construct validity was tested by correlating results to the Berg Balance Scale, the timed walking test, the Timed Up & Go test, and the Activities-specific Balance Confidence Scale. Results: ICCs for test-retest and interrater reliability of total scores were good (.96,.96, respectively) whereas reliability for single item scores was moderate to good (range,.55 -.93). The hypotheses for concurrent construct validity were confirmed with all measures (range,.68-.83). Conclusions: The DGI showed high reliability and showed evidence of concurrent validity with other balance and mobility scales. It is a useful clinical tool for evaluating dynamic balance people with chronic stroke.