Reliability and Validity of Dual-Task Mobility Assessments in People with Chronic Stroke.

Lei Yang,Chengqi He,Marco Yiu Chung Pang,François Tremblay

doi:10.1371/journal.pone.0147833

Abstract

BackgroundThe ability to perform a cognitive task while walking simultaneously (dual-tasking) is important in real life. However, the psychometric properties of dual-task walking tests have not been well established in stroke.ObjectiveTo assess the test-retest reliability, concurrent and known-groups validity of various dual-task walking tests in people with chronic stroke.DesignObservational measurement study with a test-retest design.MethodsEighty-eight individuals with chronic stroke participated. The testing protocol involved four walking tasks (walking forward at self-selected and maximal speed, walking backward at self-selected speed, and crossing over obstacles) performed simultaneously with each of the three attention-demanding tasks (verbal fluency, serial 3 subtractions or carrying a cup of water). For each dual-task condition, the time taken to complete the walking task, the correct response rate (CRR) of the cognitive task, and the dual-task effect (DTE) for the walking time and CRR were calculated. Forty-six of the participants were tested twice within 3–4 days to establish test-retest reliability.ResultsThe walking time in various dual-task assessments demonstrated good to excellent reliability [Intraclass correlation coefficient (ICC2,1) = 0.70–0.93; relative minimal detectable change at 95% confidence level (MDC95%) = 29%-45%]. The reliability of the CRR (ICC2,1 = 0.58–0.81) and the DTE in walking time (ICC2,1 = 0.11–0.80) was more varied. The reliability of the DTE in CRR (ICC2,1 = -0.31–0.40) was poor to fair. The walking time and CRR obtained in various dual-task walking tests were moderately to strongly correlated with those of the dual-task Timed-up-and-Go test, thus demonstrating good concurrent validity. None of the tests could discriminate fallers (those who had sustained at least one fall in the past year) from non-fallers.LimitationThe results are generalizable to community-dwelling individuals with chronic stroke only.ConclusionsThe walking time derived from the various dual-task assessments generally demonstrated good to excellent reliability, making them potentially useful in clinical practice and future research endeavors. However, the usefulness of these measurements in predicting falls needs to be further explored. Relatively low reliability was shown in the cognitive outcomes and DTE, which may not be preferred measurements for assessing dual-task performance.

Highlights

Functional mobility in real life situations often necessitates the ability to divide attention between two or more tasks
The walking time in various dual-task assessments demonstrated good to excellent reliability [Intraclass correlation coefficient (ICC2,1) = 0.70–0.93; relative minimal detectable change at 95% confidence level (MDC95%) = 29%-45%]
The walking time derived from the various dual-task assessments generally demonstrated good to excellent reliability, making them potentially useful in clinical practice and future research endeavors

Summary

Introduction

Functional mobility in real life situations often necessitates the ability to divide attention between two or more tasks (i.e., dual-tasking). Understanding how the addition of a cognitive task during walking interferes with the mobility performance in people with stroke has high relevance to rehabilitation [1]. There is some evidence that dual-task balance and mobility performance is impaired after stroke [2,3,4,5]. In a study involving a sample of 63 people with stroke, Hyndman et al found that 41% of these individuals stopped walking when a conversation was initiated, and that the walking time under dual-task condition in the stroke group was significantly longer than that in the age-matched controls [3]. The ability to perform a cognitive task while walking simultaneously (dual-tasking) is important in real life. The psychometric properties of dual-task walking tests have not been well established in stroke

Methods

Results

Conclusion