title: Reliability and Validity of Dual-Task Mobility Assessments in People with Chronic Stroke.
abstract: BACKGROUND
  The 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.
  
  
  OBJECTIVE
  To assess the test-retest reliability, concurrent and known-groups validity of various dual-task walking tests in people with chronic stroke.
  
  
  METHODS
  Observational measurement study with a test-retest design.
  
  
  METHODS
  Eighty-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.
  
  
  RESULTS
  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 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.
  
  
  CONCLUSIONS
  The results are generalizable to community-dwelling individuals with chronic stroke only.
  
  
  CONCLUSIONS
  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. 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.
authors.affiliation: Department of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.|Institute of Disaster Management and Reconstruction, Sichuan University -The Hong Kong Polytechnic University, Chengdu, Sichuan, China.|Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.
authors.forename: Chengqi
authors.initials: C
authors.lastname: He
authors.affiliation: Department of Rehabilitation Sciences, Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Marco Yiu Chung
authors.initials: MY
authors.lastname: Pang
mesh_terms: D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D004856:Postural Balance / Q000502:physiology; D011594:Psychometrics / Q000379:methods*; D015203:Reproducibility of Results; D020521:Stroke / Q000175:diagnosis / Q000503:physiopathology*; D013647:Task Performance and Analysis; D016138:Walking / Q000502:physiology*