Person-Environment Interactions and Older Adult Mobility
Open Access
- Author:
- Freed, Sara Ann
- Graduate Program:
- Human Development and Family Studies
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- September 21, 2021
- Committee Members:
- Jacqueline Mogle, Major Field Member
Alyssa Gamaldo, Major Field Member
Yiqi Zhang, Outside Unit & Field Member
Lesley Ross, Chair & Dissertation Advisor
Charles Geier, Program Head/Chair - Keywords:
- aging
development
transportation
mobility
driving
older adults
environment
gerontology - Abstract:
- Abstract Maintenance of personal mobility is one of the most important components of lifespan development and indicators of successful aging. Given its associations with older adults’ health and well-being, this dissertation takes a developmental approach in considering mobility an indicator of successful aging. Guided by theories by Hans Werner-Wahl and Paul Baltes, the dissertation aims to elucidate person-environment interactions in determining older adults’ mobility. Though mobility research often conceptualizes mobility as driving versus not driving, this dissertation considers the full spectrum of older adult mobility including not only the modes of transportation older adults take but also multiple indicators of driving mobility in order to gain a fuller picture of older adults’ mobility. Both papers use data from the 2017 National Household Travel Survey (NHTS). The NHTS is a nationally representative sample of households in the 50 US states and the District of Columbia conducted by the Department of Transportation. The survey was conducted across twelve months of the year and seven days a week in order to provide a representative estimation of travel across seasons and weekends/weekdays. The NHTS surveyed 89,757 people 62 years and older from 62,289 households, ranging in age from 62 to 92 years of age (M=71.57, SD=7.48). About a fifth of participants (18%) reported a health-related travel difficulty, and 28% experienced in-person license renewal. Since the dataset includes multiple participants per household, each paper addresses the dependencies in the dataset in different ways. Paper 1 examines a controversial social environmental predictor of older adults’ mobility: license renewal policy. There is little evidence for the safety benefits of more stringent license renewal laws for older drivers in the United States. However, some work in the United States suggests that in-person license renewal policies in particular are associated with lower driving iv mobility among older adults. Paper 1 is the first study to my knowledge that examines how health difficulties may interact with license renewal policies in predicting multiple indicators of driving mobility. Using information from the National Conference of State Legislatures, I created a database of license renewal laws for the 50 US states based on publications from the National Conference of State Legislatures with variables indicating whether the state had inperson license renewal requirements for older adults and the length of time in between in-person license renewals. Using generalized estimating equations (GEE) to account for multiple observations within a household in a sample of 89,757 older adults 62 years and older in the NHTS, Paper 1 found interactions between health-related travel difficulty and in-person license renewal. Among participants who experienced in-person license renewal, participants who reported health-related travel difficulty drove significantly fewer miles than participants who did not report such difficulty. For older adults with no health-related travel difficulty, a longer renewal cycle was associated with greater annual driving mileage. For older adults with healthrelated travel difficulty, there was no association between renewal cycle length and annual driving mileage. Paper 2 uses latent class analysis (LCA) to identify groups of older adults based on their use of driving, walking, bicycling, and public transportation as a mode of transportation. Paper 2 uses a random subsample of older adults 62 and older from the NHTS (n=28,055) who did not share a household and replicates LCA results in a separate subsample. LCA identified three classes of older adults: Drivers Who Walk, Nondrivers, and Multimodal Drivers. Health-related travel difficulty and urban/rural status were related to the prevalence of each class. Regardless of urban/rural status, older adults without health limitations had a higher prevalence of Drivers Who Walk compared to older adults with health limitations. Most rural adults with health difficulties v belonged to Drivers Who Walk. Both urban and rural groups without travel difficulties had small numbers of participants in the Nondrivers class, though urban older adults with no travel difficulties had a slightly higher prevalence compared to rural older adults with no difficulties. Multimodal Drivers had the fewest older adults in its class. Among urban older adults, there was a greater difference in prevalence of Multimodal Drivers between older adults who reported travel difficulties and those who did not compared to rural older adults. Overall, Papers 1 and 2 highlight the need for research and policy to consider the role of health limitations, environment, and their interaction in determining older adults’ mobility. Research and policy must also move from mobility as a binary variable and consider the many ways in which older adults are mobile. Advances in technology and policy approaches, such as advanced driver-assistance systems (ADAS) and mobility as a service (MaaS), are possible opportunities for environmental supports on maintaining older adults’ mobility, particularly for older adults with health limitations and who live in rural areas. However, these changes must be implemented carefully in order to ensure that all older adults are able to fully participate in services to improve their mobility. The results of the current papers provide a unique contribution to our understanding of how older adults move around in their world and suggest ways that research and policy can work together to ensure older adults stay safely mobile throughout their lifespan