Enhanced gait variability index and cognitive performance in Asian adults: Results from the Yishun Study.

Background: Although gait variability has been linked to cognitive decline among older adults, the lack of a comprehensive composite gait variability score has dampened the application of gait variability.

Research Question: Does the enhanced gait variability index (EGVI) - a composite score gait variability index - provide differential and useful information on cognitive decline in community-dwelling adults from that using gait speed?

Methods: Healthy community-dwelling adults (n = 311) aged 21-90 were individually administered the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Habitual gait speed and spatiotemporal parameters were measured using a 6 m instrumented walkway system. The EGVI for each participant was calculated from five spatiotemporal parameters - step length(cm), step time(s), stance time(s), single support time(s) and stride velocity(cm/s). Linear regression models, controlling for age, gender, and education, were built to examine the independent effects of EGVI or gait speed on global cognition and individual domains.

Results: Multiple regression revealed that gait speed contributed significantly to the performance of the domain "Attention" (p = 0.04) whereas EGVI contributed significantly for the performance of the domain "Visuospatial" (p = 0.04) and "Delayed Memory" (p = 0.02).

Significance: EGVI provides differential and useful information from using gait speed alone. The EGVI may offer a solution to measure or track GV changes in relation to cognitive changes.