GIS-Based Spatial Accessibility to Urban Resources and Healthy Aging: Environmental Exposure Assessment of Frailty, Cognition, and Polypharmacy in Older Adults

Geographic information systems (GISs) can quantify spatial accessibility to urban resources relevant to healthy aging. This cross-sectional study examined whether GIS-derived, distance-based accessibility to urban facilities was associated with cognitive impairment, frailty, and polypharmacy among 317 community-dwelling adults aged ≥65 years in Talca, Chile. Residential locations were geocoded and linked to a summary Urban Quality Index (UQI) based on Euclidean distances to seven urban resource types. Physical frailty was assessed using the Fried phenotype, cognitive impairment with an abbreviated Mini-Mental State Examination, and polypharmacy as daily use of ≥5 medications. Cognitive frailty categories were defined descriptively as the coexistence of Fried frailty or pre-frailty with screening-based cognitive impairment. Frailty was present in 66.3% of participants with cognitive impairment versus 24.5% of those with normal cognition (p < 0.001). In multivariable models adjusted for age, sex, education, body mass index, and nutritional risk, low UQI was not statistically significantly associated with cognitive impairment, polypharmacy, or frailty. Exploratory resource-specific analyses suggested that participants with cognitive impairment lived farther from main squares and parks and closer to emergency health centers; these findings were not adjusted for multiple testing and are hypothesis-generating. Overall, residence-based, straight-line spatial accessibility alone may be insufficient to explain geriatric vulnerability. Longitudinal research using network-based and mobility-based measures is needed.