College of Architecture and Planning
1 Environmental Determinants of Outdoor Fall Injuries among Older Adults: A National Study
Yiwen Chen; Andy Hong; and Katherine Isaacs
Faculty Mentor: Andy Hong (City & Metropolitan Planning, University of Utah)
Abstract
Fall injuries are a public concern, and as individuals age falls become both more common and more injurious. This study assesses outdoor fall injuries among older adults and uses quantitative methods to understand how the built environment impacts fall risk and identify specific environmental fall risk factors. We analyzed data from the National Emergency Medical Services Information System (NEMSIS) to identify fall-related injuries, linking these incidents to environmental data by ZIP codes. A zero-inflated negative binomial regression model was employed to assess the association between environmental risk factors and fall-related injuries among older adults in the United States. The analysis identified six statistically significant environmental variables: urbanization, the percentage of senior population, slope, area deprivation index, the number of harsh winter days, and pedestrian intersection density. These findings provide a foundation for further investigation into how the built environment interacts with the risk of pedestrian falls.
Introduction
Fall injuries are a significant public health concern, particularly among older adults, who are more susceptible to environmental hazards while walking outdoors. Outdoor falls most commonly result from tripping or slipping, which are functions of the built environment (Timsina et al, 2017; Li et al, 2006; Lai et al, 2009). Further, the vast majority of pedestrian injuries result from falls, rather than vehicle collisions (Rundle et al, 2024).
Our study assesses outdoor fall injuries among older adults to understand how the built environment impacts fall risk and identify specific environmental fall risk factors. Past research on pedestrian falls has primarily relied on personal accounts of falls, rather than on quantitative environmental data. Our study uses National Emergency Medical Services Information System (NEMSIS) incident data to identify fall-related injuries. After linking fall incidents to environmental data by ZIP code, we use zero inflated negative binomial regression model to evaluate environmental risk factors associated with fall-related injuries among older adults in the United States.
Method
Data
For this study, we used 2018-2022 data from NEMSIS, a national database of EMS event records. No IRB oversight was necessary for our analysis since the records are released as a de-identified, publicly available dataset. Over 12 million events were recorded by over 10,000 EMS agencies in all fifty states and the District of Columbia. The only geographic identifiers available in the public dataset are Census Region and Division. However, NEMSIS makes some geographic variables available to researchers as masked, de-identified data ele