Date of Award

Spring 3-22-2020

Degree Type


Degree Name

PhD Health Sciences


Health and Medical Sciences


Ning Jackie Zhang, PhD

Committee Member

Terrance Cahill, EdD

Committee Member

Michelle D'Abundo, PhD


Falls, Risk factors, Older adults, Cognitively impaired, Gait performance, Use of central nervous system medication


Falls are the second leading cause of accidental or unintentional injury deaths worldwide among older adults. Although researchers extensively studied the risk factors of falls, there were limit studies focus on the impact of medication effects, and gait performance on the falls among cognitively impaired elderly. This study fills the gap and aims to understand: 1) the risk factors associated with occurrence of fall between older adults with cognitive impairment and the overall older adults, 2) the association between gait performance and falls 3) the association between the use of central nervous system (CNS) medications and falls, and 4) the mediation effect of gait performance on the relationship between the use of CNS medications and falls. The study used a longitudinal cohort design that included five years of data from elderly participants in the NIA Health Aging and Body Composition (HealthABC) study. This study used Generalized Estimating Equation and path analysis to test the proposed associations. The findings demonstrate that risk factors for older adults with cognitive impairment were different from the general population. Indeed, gender, depression symptom score, cognitive function score, the use of CNS medication, and narrow walking speed were significantly associated with the occurrence of falls among older adults. For the cognitively impaired older adults, study result only supported that there was a statistically significant association between usual walking speed and falls. For cognitive impaired older adults, who had faster usual walking speed was less likely to fall, with an odds ratio of 0.18 and 95% CI (0.04, 0.84). In addition, cognitively normal older adults who were taking CNS medication had a higher risk of a fall compared with the odds ratio of 1.36, 95% CI (1.01, 1.85). Finally, the study did not support that gait performance as a mediator between the use of CNS medication and falls among older adults over time. In summary, the study results confirmed that risk factors associated with falls among cognitively impaired older adults were different from the general older adults. It is crucial to evaluate fall risks included multiple factors in the assessment tool. The study findings support the use of a comprehensive fall risk assessment tool that including multiple risk factors to evaluate fall risk among older adults.