The test-retest reliability of gait-related dual task performance in community-dwelling fallers and non-fallers.

Gait-related dual task tests have been used to assess differences between fallers and non-fallers, without a thorough assessment of reliability. This study investigated the test-retest reliability of eight gait-related dual and one triple task tests in forty-four community-dwelling older adults (twenty with and twenty-four without a history of falls). The reliability of single, dual and change in performance (percentage change) from single to dual task conditions was assessed. The results showed that single and dual task walking time had fair to excellent reliability (ICC=0.53-0.92) across tasks. The percentage change in walking time (dual-task decrement) showed only poor to good reliability (ICC=-0.11 to 0.75). Cognitive task performance speed and accuracy showed poor to good reliability in single and dual task conditions (ICC=-0.16 to 0.83). The difference between the two conditions in speed and accuracy showed poor to fair reliability (ICC=-0.40 to 0.51). A secondary motor task (carrying a cup of water) ranged from slightly to moderately reliable in dual task conditions and when change in performance was measured (kappa=0.18-0.57). This study showed that simple dual task tests are reliable in the single and dual conditions but measures of change in performance, which are recommended for dual task assessment, are less reliable and is something which needs to be considered in future research. Of the nine examined, only one test, the walking while talking test, showed good reliability on primary and secondary tasks.