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 (SD_diff); 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– (SD_diff) 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 – (SD_diff) 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.