Abstract
Background and Purpose: Fall-related injuries are a leading cause of institutionalization and morbidity in older adults. Limitations in cognition, including deficits in higher cognitive processes, like executive function (EF), contribute to a higher risk of falling in older adults. Specifically, declines in EF have been associated with changes in gait, limited mobility, and an increased frequency of falling. It is unknown whether associations between performance on commonly used clinical assessments of EF and performance on commonly used physical performance measures of fall risk are present. The purpose of this study was to examine the relationship between a clinical measure of EF, the Trail Making Test Part B (TMT-B), and 3 physical performance measures of fall risk: the Timed Up and Go (TUG) test, gait speed, and the Five Times Sit to Stand (FTSTS) test, in a group of community-dwelling older adults.
Methods: Forty-seven community-dwelling older adults met the inclusion/exclusion criteria. Demographic information was obtained and measures of fall risk and cognition were performed. Correlations and linear regression analyses to assess relationships between measures were completed. To account for the high prevalence of mild cognitive impairment (MCI) in this population, the sample was screened and stratified for MCI in post hoc analyses.
Results: The EF performance was not significantly correlated with performance on the FTSTS test ([rho] = 0.26, P > .05) but was significantly correlated with the TUG test ([rho] = 0.31, P < .05) and gait speed (r = -0.36, P < .05). These relationships remained after adjusting for age and education in multivariate models. Results from post hoc analyses demonstrated that only those with MCI had significant relationships between EF and physical performance measures. TMT-B scores in the MCI group were significantly correlated with gait speed ([rho] = -0.51, P < .05) and TUG test ([rho] = 0.58, P < .05).
Discussion: A significant relationship exists between performance on clinical assessments of EF and fall risk assessments that integrate a mobility task for those individuals who screen positive for MCI. For those who screened negative, no significant relationship exists. Given the large prevalence of undiagnosed MCI in community-dwelling older adults, this finding could be used as an indication to screen older adults for MCI.
Conclusions: Screening tools that require cognitive resources such as gait speed appear to have significant relationships with performance of EF for those who screen positive for MCI. This information could be used clinically to identify older adults with cognitive limitations, which could put them at higher risk for falling.