The effects of fatigue and fatigability on fall risk in older adults

The rapidly increasing number and proportion of older adults are expected to have profound impact on public health. As the population of older adults increases, the proportion of the population experiencing falls and fall injuries is increasing. In addition to expensive medical costs, falls represent a significant cause of disability and mortality. The U.S. Preventive Services Task Force stated a need for clinically relevant tools to identify older adults at increased fall risk; fatigue and fatigability are potential tools for identifying older adults at increased fall risk. Fatigue is a common complaint among older adults. Fatigue and fatigability, both physical and mental, are associated with multiple fall risk factors (i.e., frailty, slower gait speed, and lower physical function) and may play a role in the disablement pathway. The purpose of this dissertation is to examine fatigue as well as physical and mental fatigability as potentially modifiable fall risk factors. Specifically, we aim to examine the impact of perceived global fatigue on prospective falls, validate the Pittsburgh Fatigability Scale (PFS) mental subscale, and determine the role that physical and mental fatigability independently play on prospective fall and fall injuries. Public Health Significance: Although fatigue and fatigability are associated with factors that increase fall risk, they are not yet recognized as significant fall risk factors. The public health implications of understanding the effects fatigue and fatigability on falls and fall injuries is to provide a novel measurement to identify older adults at increased risk of falls and fall injuries in an effort for early intervention.