Relating built environment to physical activity: two failures to validate

Evidence synthesis - A systematized literature review on the associations between neighbourhood built characteristics and walking among Canadian adults

INTRODUCTION

Evidence to date suggests that the built environment has the potential to facilitate and even discourage physical activity. A limitation of previous reviews is that they have typically not been country-specific. We conducted a systematized literature review of quantitative studies that estimated associations between the built environment-which were objectively measured-and walking among Canadian adults.

METHODS

Five scientific databases were searched for peer-reviewed studies published in all years up to December 31, 2016, that estimated the association between the built environment (i.e. objectively measured using audits and Geographic Information Systems [GIS]) and physical activity among a sample of Canadian adults. The database searches, title and abstract screen, full-text review and data extraction were undertaken by two reviewers.

RESULTS

Of 4140 articles identified, 25 met the inclusion criteria. Most studies included data from a single Canadian province. All but two studies were cross-sectional. Most studies captured self-reported walking for transportation and walking for any purpose. Overall walkability and land use were consistently associated with walking for transportation, while proximity to destinations was associated with walking for any purpose.

CONCLUSION

Our review findings suggest that the built environment is potentially important for supporting adult walking. Overall walkability, land use and proximity to destinations appear to be important given their association with transportation walking and walking for any purpose.

Environments favorable to healthy lifestyles: A systematic review of initiatives in Canada

BACKGROUND

In recent years, a number of initiatives aimed at promoting healthy lifestyles in health-friendly environments have been implemented. The purpose of this review is to synthesize initiatives conducted in Canada and documented in publications for the period 1995-2015 in order to gain a better understanding of their objectives and impacts.

METHODS

A systematic review of Canadian initiatives published over the past 20 years was conducted from multiple databases (i.e., Scopus, SPORTDiscus, PubMed, Academic search complete, Reseausante.com, Cairn, and Erudit). In total, 264 publications were identified and retained for the final analysis based on 5 criteria: (1) publication between 1995 and 2015, (2) online availability, (3) research conducted in Canada, (4) main topic related to environments favorable to healthy lifestyles (EFHL), and (5) publication in French or English.

RESULTS

A sharp increase in the number of studies on EFHL was observed between 2010 and 2015 (57%). Two major lifestyle components-physical activity and nutrition-and 2 environmental aspects-neighborhood and built environment-were the elements most frequently examined regarding adults (48%), young people (34%), and seniors (9%), using quantitative (60%) and qualitative (18%) methods. Furthermore, the analysis reveals a greater focus on the municipal (53%) than the national or provincial levels (31%).

CONCLUSION

This work is a first map of Canadian studies related to EFHL. It clarifies the definition of EFHL and classifies its components. As well, it documents the issues raised, the research methods employed, and the role of stakeholders, while outlining a new research agenda that includes dimensions of EFHL formerly neglected by researchers, namely, political and sociocultural spheres of action.

Active Transportation on a Complete Street: Perceived and Audited Walkability Correlates

Few studies of walkability include both perceived and audited walkability measures. We examined perceived walkability (Neighborhood Environment Walkability Scale—Abbreviated, NEWS-A) and audited walkability (Irvine–Minnesota Inventory, IMI) measures for residents living within 2 km of a “complete street”—one renovated with light rail, bike lanes, and sidewalks. For perceived walkability, we found some differences but substantial similarity between our final scales and those in a prior published confirmatory factor analysis. Perceived walkability, in interaction with distance, was related to complete street active transportation. Residents were likely to have active transportation on the street when they lived nearby and perceived good aesthetics, crime safety, and traffic safety. Audited walkability, analyzed with decision trees, showed three general clusters of walkability areas, with 12 specific subtypes. A subset of walkability items (n = 11), including sidewalks, zebra-striped crosswalks, decorative sidewalks, pedestrian signals, and blank walls combined to cluster street segments. The 12 subtypes yielded 81% correct classification of residents’ active transportation. Both perceived and audited walkability were important predictors of active transportation. For audited walkability, we recommend more exploration of decision tree approaches, given their predictive utility and ease of translation into walkability interventions.

Check the score: Field validation of Street Smart Walk Score in Alberta, Canada

Walk Score® is a proprietary walkability metric that ranks locations by proximity to destinations, with emerging health promotion applications for increasing walking as physical activity. Currently, field validations of Walk Score® have only occurred in metropolitan regions of the United States; moreover, many studies employ an earlier Walk Score® version utilizing straight line distance. To address this gap, we conducted a field validation of the newest, network-based metric for three municipal types along a rural-urban continuum in Alberta, Canada. In 2015, using street-level systematic observations collected in Bonnyville, Medicine Hat, and North Central Edmonton in 2008 (part of the Community Health and the Built Environment (CHBE) project), we reverse engineered 2181 scores with the network Walk Score® algorithm. We computed means, 95% confidence intervals, and t-tests (α = 0.05) for both sets of scores. Applying the Clifford-Richardson adjustment for spatial autocorrelation, we calculated Spearman's Rank Correlation Coefficients (rho, rs) and adjusted p-values to measure the strength of association between the derived scores and original network scores provided by Walk Score®. Spearman's rho for scores were very high for Bonnyville (rs = 0.950, adjusted p < 0.001), and high for Medicine Hat (rs = 0.790, adjusted p < 0.001) and North Central Edmonton (rs = 0.763, adjusted p < 0.001). High to very high correlations between derived scores and Walk Scores® field validated this metric across small, medium, and large population centres in Alberta, Canada. However, we suggest caution in interpreting Walk Score® for planning and evaluating health promotion interventions, since the strength of association between destinations and walking may vary across different municipal types.

Developing a Measure of Traffic Calming Associated with Elementary School Students' Active Transport

The objective of this study is to develop a measure of traffic calming with nationally available GIS data from NAVTEQ and to validate the traffic calming index with the percentage of children reported by school administrators as walking or biking to school, using data from a nationally representative sample of elementary schools in 2006-2010. Specific models, with and without correlated errors, examined associations of objective GIS measures of the built environment, nationally available from NAVTEQ, with the latent construct of traffic calming. The best fit model for the latent traffic calming construct was determined to be a five factor model including objective measures of intersection density, count of medians/dividers, count of low mobility streets, count of roundabouts, and count of on-street parking availability, with no correlated errors among items. This construct also proved to be a good fit for the full measurement model when the outcome measure of percentage of students walking or biking to school was added to the model. The traffic calming measure was strongly, significantly, and positively correlated with the percentage of students reported as walking or biking to school. Applicability of results to public health and transportation policies and practices are discussed.