Optimizing mobility in later life: the role of the urban built environment for older adults aging in place.

Hazards in the urban built environment can create barriers to mobility among older adults aging in place. We investigated the relationship between urban built environment characteristics and 15-month trajectories of mobility disability in a sample of 1,188 older adults living in Detroit, MI, a city that has undergone rapid economic and structural decline. Data come from the Michigan Minimum Data Set for Home Care (2001-2008), an enumerative database of older adults in Michigan who qualify for federal or state-funded home and community-based long-term care through a Medicaid waiver program. Standardized assessments are made at intake and every 90 days by case managers. Built environments were assessed with a virtual audit using the "Street View" feature of Google Earth. A summary accessibility score was created for each block based on a count of the number of accessible features (e.g., continuous barrier-free sidewalks and proximity of public transportation). Using growth mixture models, two latent trajectories of outdoor mobility were identified: one capturing occasional outdoor mobility (representing 83 % of the sample) and one capturing almost no mobility outside the home. Controlling for sociodemographic and health risk factors, individuals living in more accessible environments had a 18 % higher odds of being in the more mobile group (OR = 1.18, 95 % CI = 1.01, 1.41). These findings emphasize the importance of the built environment for mobility among urban-dwelling older adults.