The Association Between Street Network Accessibility and Cognitive Impairment

Abstract

AbstractBackgroundAccess to different amenities has been hypothesised to reduce the risk of cognitive impairment in older adults. Literature in urban planning shows that a well‐connected street network enables access to amenities, however, the role of street network accessibility has not been studied extensively in relation to cognitive function. The aim of this study is to investigate the cross‐sectional relationship between street network accessibility and cognitive impairment in older people in England, UK.MethodThe baseline data from the Cognitive Function and Ageing Study (CFAS) II (2008‐2011), a cohort study of people aged 65+ across three areas in England, was used (N = 7485) excluding 144 housebound participants. Cognitive impairment was defined by the Mini Mental State Exam (MMSE) score: mild‐severe (MMSE<26) and moderate‐severe (MMSE<21). Using Geographical Information System (GIS) data, proximity to a main road was represented by betweenness centrality (shortest routes corresponding to high potential of through movement) of the street network, using normalised angular choice (NACH ‐ range of 0‐1.5, with 0.9+ meaning a main road). Mean NACH was calculated within 300m walk of participants’ postcode centroid and categorised into tertiles (low = NACH<0.8, medium = NACH 0.8‐0.9, high = NACH>0.9). Logistic regression was used to investigate the relationship between proximity to a main road, the risk of mild‐severe and moderate‐severe cognitive impairment adjusting for age, sex, education, and area deprivation.ResultThe prevalence was 24% for mild‐severe cognitive impairment and 7.3% for moderate‐severe cognitive impairment. Compared to those living at low proximity from a main road, those who lived at medium (OR 0.817 95% CI [0.716, 0.932]) and high proximity (OR 0.756 95% CI [0.662, 0.863]) had lower risk of mild‐severe cognitive impairment. The adjusted associations remained similar (OR 0.771 95% CI [0.671, 0.886] for medium proximity, OR 0.755 95% CI [0.656, 0.869] for high proximity). Proximity to a main road was not associated with moderate‐severe cognitive impairment.ConclusionThe results suggest evidence for the role of proximity to a main road in reducing the risk of mild‐severe cognitive impairment in non‐housebound individuals, but not moderate‐severe cognitive impairment. More research is needed on other aspects of street network accessibility.