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Innov Aging
Innov Aging
innovateage
Innovation in Aging
2399-5300 Oxford University Press US 

10.1093/geroni/igaa057.759
igaa057.759
Abstracts
Session 2908 (Poster)
Fall Risk and Fall Prevention
AcademicSubjects/SOC02600
Improved Processing Speed Is a Potential Mechanism by Which Exercise Reduces Falls
Liu-Ambrose Teresa 1 Davis Jennifer 2 Falck Ryan 1 Khan Karim 1 1 
University of British Columbia, Vancouver, British Columbia, Canada
2 
University of British Columbia, Kelowna, British Columbia, Canada
2020 
16 12 2020 
16 12 2020 
4 Suppl 1 Program Abstracts from The GSA 2020 Annual Scientific Meeting “Turning 75: Why Age Matters”235 235
© The Author(s) 2020. Published by Oxford University Press on behalf of The Gerontological Society of America.2020This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Abstract
A 12-month trial demonstrated the Otago Exercise Program (OEP), a home-based exercise program of strength and balance retraining exercises, significantly reduced the rate of subsequent falls among 344 older adults receiving care after a fall (JAMA, 2019). A significant improvement in processing speed, as measured by the Digit Symbol Substitute Test (DSST), was also observed. Given the DSST is a predictor of falls, we conducted mediation analyses to determine whether improved DSST mediated the effects of OEP on rate of: 1) total falls; 2) non-injurious falls; 3) mild injurious falls; and 4) severe injurious falls over the 12-month trial. Our causal mediation analyses were conducted using the mediation package in R, using quasi-Bayesian estimates and 95% confidence intervals. Compared with usual care, OEP significantly reduced the rate of total falls (IRR= 0.64; 95% CI: 0.44, 0.91; p= 0.013) and mild injurious falls (IRR= 0.49; 95% CI: 0.31, 0.77; p= 0.002). Improved DSST score was also associated with lower mild injurious fall rates (IRR= 0.95; 95% CI: [0.91, 0.99]; p= 0.014). Formal mediation analyses showed that improved DSST was a significant mediator of the effect of OEP on the rate of mild injurious falls (95% CI: -0.15, 0.00; p= 0.036). Improved processing speed may be a mechanism by which exercise reduces mild injurious falls.