Reliability of gait speed measured by a timed walking test in patients one year after stroke

Abstract

Objective: To assess the reliability of gait speed in late-stage stroke patients. Design: Test–retest reliability of three timed walks to 10 metres repeated during two assessments one week apart. Setting: The patient's home. Subjects: Twenty-two stroke patients with mobility problems more than one year after stroke. Main outcome measure: Gait speed measured in seconds taken to walk 10 metres. Statistical analysis: Intraclass correlations (ICCs) with 95% con”dence interval (CI) and the Bland and Altman method for assessing agreement by calculating the mean difference between measurements ( d–); the 95% CI for d–; the standard deviation of the difference (SDdiff); a reliability coef”cient and the 95% limits of agreement. Results: There was a trend for decreased times taken to walk 10 metres both within each assessment and between assessments. ICCs for within assessment reliability were 0.95–0.99. The d– (SDdiff) for the second and third walks for assessment 1 was –1.00 (2.63) seconds and for assessment 2 was –0.70 (1.58) seconds. The reliability coef”cient was 5.26 for assessment 1 and 3.17 for assessment 2. ICCs for between-assessment reliability were 0.87–0.88. The d – (SDdiff) for the comparison of the third walks at assessment 1 and assessment 2 was –0.90 (5.01) seconds. The reliability coef”cient was 10.02 and the 95% limits of agreement were –10.92 to +9.12 seconds. Conclusion: Within-assessment gait speed measured at home is highly reliable. The between-assessment reliability of gait speed measurement is less reliable but comparable with other studies.