The evidence on links between neighborhood walkability and physical activity and body mass index remains limited because there have been few longitudinal studies with repeated measures of neighborhood walkability and health behavior and outcomes. While large cohort studies with long-term follow-up, residential address history, and health outcomes are available, the lack of neighborhood walkability measures with the same temporal and geographic coverage limits the use of these cohorts to study how urban form shapes health. We recently published a paper in the Journal of Urban Health describing a new measure of neighborhood walkability, the Built Environment and Health-Neighborhood Walkability Index (BEH-NWI), that can be calculated across communities in the U.S. and historically over the past three decades.
We retrospectively measured neighborhood walkability for 2010 for 1 km circles centered on each Census block in NYC (N=38,526) using the BEH-NWI and using our prior NWI. The correlation between walkability scores calculated from our BEH-NWI and our prior NWI across NYC is 86%, and BEH-NWI scores across NYC are also highly correlated with circa 2010 WalkScore data.
We used the BEH-NWI with two studies that previously collected physical activity, health and residential address data, the NYU Women’s Health Study and the NYC Department of Health and Mental Hygiene’s 2011 Physical Activity and Transit (PAT) Survey. We calculated BEH-NWI scores for the residential neighborhoods of participants in the NYU Women’s Health Study when they first enrolled into the study circa 1990. Higher BEH-NWI scores were significantly associated with greater self-reported walking per week and lower body mass index among study participants. PAT Survey participant’s wore accelerometers for a week to objectively measure their physical activity and we found that higher BEH-NWI scores were significantly associated higher levels of physical activity. BEH-NWI scores and WalkScore data were equivalently predictive of total physical activity among PAT Survey participants, but the BEH-NWI has the advantage that it can be retrospectively calculated across the U.S. back to 1990.
The BEH-NWI can be a valuable new resource for research on how urban form and built environments affect physical activity, obesity, and health. The BEH-NWI is grounded conceptually in urban planning/design theory and uses data that are available nationwide and historically as far back as 1990. This measure will allow researchers to leverage existing longitudinal human health datasets for new insights into the role of neighborhood features in shaping health.