Year of Award


Document Type


Degree Type

Doctor of Philosophy (PhD)

Degree Name

Public Health

Department or School/College

School of Public and Community Health Sciences

Committee Chair

Erin O. Semmens

Commitee Members

Keith Anderson, Sophia Newcomer, Curtis Noonan, Tony Ward


Activities of Daily Living, Falls, Gait Speed, Mild Cognitive Impairment


University of Montana


Background: Falls in older adults are a significant public health challenge. Fall prevention as well as intervention after a fall both are critical to reduce the negative consequences and improve quality of life in older age.

Purpose: 1) Quantify the association between gait speed and fall risk in a cross-sectional analysis for older adults with and without cognitive impairment. 2) Determine if there is an association between change in gait speed and fall risk in a longitudinal analysis including older adults with and without cognitive impairment. 3) Quantify the association between falls and difficulty with activities of daily living (ADLs) and instrumental activities of daily living (IADLs) and determine the trajectory of difficulty with ADLs/IADLs pre- and post-fall for older.

Methods: The study population for this research was the Ginkgo Evaluation of Memory Study, a randomized controlled trial, conducted from 2000-2008, including 3069 older adults from four locations in the United States. The longitudinal study design, number of measures, and rigorous ascertainment of MCI and dementia provided an excellent data set for this research, which included a cross-sectional analysis of gait speed and falls, a longitudinal analysis of change in gait speed and falls, and falls and difficulty with ADLs/IADLs using Cox proportional hazards models, and latent class trajectory modeling to determine trajectories of difficulty with ADLs/IADLs pre- and post- fall.

Results: 1) The results of this study provide evidence of a significant association between faster gait speed and lower fall risk for older adults. 2) A decrease in gait speed of more than 0.15 m/s (mean speed 0.93 m/s) over 12 months is associated with increased risk of falls for older. 3) Falls are associated with an increased risk of difficulty with ADLs/IADLs, which persists and worsens over time for some older adults.

Conclusion: Gait speed and change in gait speed could be used as screening tools for fall risk in older adults with and without mild cognitive impairment. Understanding the characteristics of older adults more likely to have difficulty with ADLs and IADLs post-fall can be utilized to target interventions to decrease fall-related negative outcomes.



© Copyright 2021 Claire Elaine Adam