Association of subsequent falls with evidence of dual-task interference while walking in community-dwelling individuals after stroke

Objective: The aim of this study was to examine the fall predictive value of single-task walking tests and extent of interference observed in dual-task walking tests in ambulatory individuals post stroke.

Design: This is an observational study with prospective cohort.

Setting: The study was conducted at the university laboratory.

Participants: A total of 91 community-dwelling individuals with chronic stroke participated in the study.

Main outcome measures: Time required to complete a 10-m walk test with and without obstacle negotiation was measured in isolation and in conjunction with performance of a verbal fluency task (category naming). Fall incidence, circumstances, and related injuries were recorded by monthly telephone calls for 12 months.

Results: A total of 91 individuals (mean (SD) age = 62.7 (8.3) years; mean (SD) post-stroke duration = 8.8 (5.3) years) participated in the study; 29 (32%) of them reported at least one fall during the follow-up period, with a total of 71 fall episodes. There was a significant difference in obstacle-crossing time under single-task (mean difference = 8.3 seconds) and dual-task (mean difference = 7.4 seconds) conditions, and also the degree of interference in mobility performance (increased dual-task obstacle-crossing time relative to the single-task obstacle-crossing time; mean difference = 3.3%) between the fallers and the non-fallers (P < 0.05). After adjusting for the effects of other relevant factors, a greater degree of interference in mobility performance remained significantly associated with a decreased risk of falling (adjusted odds ratio = 0.951, 95% CI = 0.907-0.997, P = 0.037).

Conclusion: The degree of mobility interference during dual-task obstacle-crossing was the most effective in predicting falls among all the single-task and dual-task walking measure parameters tested. This simple dual-task walking assessment has potential clinical utility in identifying people post stroke at high risk of future falls.