Urban Environment and Outdoor Walking Mobility Among Older Adults With and Without Cognitive Impairment in Singapore: Formative Study.

Background: There is increasing recognition of the environment's role in shaping cognitive functioning among older adults. Objective: This study aimed to examine the relationship between the outdoor mobility of older adults with and without cognitive impairment and the built environment in 3 urban neighborhoods in Singapore, specifically 3 urban, high-density subzones selected a priori. Methods: Outdoor walking mobility in daily life gait speed (DGS) was collected continuously for 1 week using a previously validated hybrid mobility tracker. Mini-Mental State Examination cut-offs by educational levels were used to differentiate cognitive impairment (CI) and without cognitive impairment (nonCI). The environmental characteristics examined were gross plot ratio and land use. Statistical correlations were used to examine the associations between older adults' outdoor mobility and built environment for all CI and nonCI groups. Two case examples were also used to provide a location-based heatmap on DGS for 3 consecutive days. Results: The overall mean DGS was 0.75m/s (SD 0.12) for the nonCI group and 0.73m/s (SD 0.08) for the CI group. The between-group difference (0.02m/s) was below commonly cited thresholds. Exploratory land-use and zone-specific summaries suggested context-dependent variation, such as residential areas (CI: 0.80m/s and nonCI: 0.62m/s). Higher GPR was associated with faster DGS in the nonCI group (β=0.04, 95% CI 0.01-0.07, P=.04) and slower DGS in the CI group (β=-.13, 95% CI -0.20 to -0.04, P=.01). CI participants spent more time in commercial and business zones than nonCI participants, while both groups spent the majority of walking time in residential areas. However, estimates were based on small subsamples and multiple unadjusted comparisons and should be interpreted as hypothesis-generating. Conclusions: This formative, exploratory study suggests that environmental typologies, particularly GPR and land use, may be associated with differences in mobility patterns between older adults with and without cognitive impairment; subgroup patterns were exploratory and not powered for clinical interpretation. Policy implications include integrating fine-grained environmental metrics into age-friendly urban planning. Clinically, mobility assessments should account for environmental context. Future research should use larger, more diverse, and longitudinal samples to confirm these associations and guide the design of supportive urban environments for cognitively diverse aging populations, noting that findings are context-specific to high-density urban environments. However, given data limitations, unmeasured factors such as comorbidity burden, habitual physical activity, socioeconomic context, and caregiver accompaniment may also contribute to the observed patterns, and findings should be interpreted accordingly.