Objectives: To investigate the concordance between walking (WS) and psychomotor speed (PS), correlates of both tasks, and their capacity to predict mortality in the elderly.
Design, setting and participants: Seven-year cohort study of 1,365 community-dwelling subjects aged 65-95 years, participating in the Bordeaux sample of the Three City Study, a French prospective cohort designed to evaluate the risk of cognitive decline attributable to vascular risk factors.
Measurements: Participants completed a battery of cognitive assessments including time to complete Trail Making Test A used as a PS measure, and a measure of WS. Socio-demographic determinants, co-morbidities, functional and cognitive evaluation, and incident mortality were taken into account.
Results: Mean age was 75.7 (SD ± 5.4) years. WS and TMT-A speed have very low concordance (kappa coefficient=.05). The correlates of each measure were different: mostly clinical co-morbidities for WS, and mostly cognition and function for TMT-A speed. However, TMT-A speed and WS are both independent predictors of death after seven years of follow-up.
Conclusion: WS and TMT-A speed could be considered as two different dimensions of age-related slowness, but both performances were associated with higher risk of mortality.