Development and Validation of a Walkability Index from Google Street View Audits

Background: Walking promotes health and helps older adults age actively. However, with both cognitive and physical functions deteriorating with age, walking becomes a complex process that is dependent not only on the health of brain and body, but increasingly on the surrounding built and social environment. Built environment is related to physical activity as it can either foster or hinder mobility. The aim of this study is to create a valid scale that utilizes objectively assessed environmental characteristics to describe the walkability of a participant’s environment. Methods: We used historical neighborhood audits from a cohort of older adults in Pittsburgh, Pennsylvania from 2007 to construct and validate the scale using exploratory factor analysis. We then applied confirmatory factor analyses in a sample of older adults participating in a randomized control trial of a physical therapy intervention in Pittsburgh and recruited between 2016-2019. Results: In a sample of 246 older adults in the greater Pittsburgh area, we identified 3 walkability factors. Factor 1 had demonstrated strong internal consistency (alpha=0.80) and consisted of mixed land use, commercial uses present, apartments present, educational facilities present, lighting present, and public recreation present. Factor 2 demonstrated fair consistency (alpha=0.57) but good face validity, including no undeveloped land, no slopes, no single-family homes, less than 6 stairs, good quality sidewalks, and benches present. Factor 3 had fair consistency (alpha=0.40) but without good face validity. Factor 1 was more strongly related to positive outlook of neighborhood as well as lower socioeconomic standing compared to Factor 2. Conclusion: These findings could serve as a tool for identifying neighborhood factors related to walkability that could be targets for policy interventions. Moreover, the positive implications of a walkable neighborhood could be substantial for the health of the public, especially older adults