International evaluation of the Microscale Audit of Pedestrian Streetscapes (MAPS) Global instrument: comparative assessment between local and remote online observers.

OBJECTIVES: The use of online imagery by non-local observers to conduct remote, centralized collection of streetscape audit data in international studies has the potential to enhance efficiency of collection and comparability of such data for research on built environments and health. The objectives of the study were to measure (1) the consistency in responses between local in-field observers and non-local remote online observers and (2) the reliability between in-country online observers and non-local remote online observers using the Microscale Audit of Pedestrian Streetscapes Global tool to characterize pedestrian-related features along streets in five countries. METHODS: Consistency and inter-rater reliability were analyzed between local and non-local observers on a pooled database of 200 routes in five study regions (Melbourne, Australia; Ghent, Belgium; Curitiba, Brazil; Hong Kong, China; and Valencia, Spain) for microscale environmental feature subscales and item-level variables using the intraclass correlation coefficient (ICC). RESULTS: A local in-field versus remote online comparison had an ICC of 0.75 (95 % CI: 0.68-0.80) for the grand total score. An ICC of 0.91 (95 % CI: 0.88-0.93) was found for the local online versus remote online comparison. Positive subscales yielded stronger results in comparison to negative subscales, except for the similarly poor-performing positive aesthetics/social characteristics. CONCLUSIONS: This study demonstrated remote audits of microscale built environments using online imagery had good reliability with local in-field audits and excellent reliability with local online audits. Results generally supported remote online environmental audits as comparable to local online audits. This identification of low-cost and efficient data acquisition methods is important for expanding research on microscale built environments and physical activity globally.

International comparison of observation-specific spatial buffers: maximizing the ability to estimate physical activity.

BACKGROUND: Advancements in geographic information systems over the past two decades have increased the specificity by which an individual's neighborhood environment may be spatially defined for physical activity and health research. This study investigated how different types of street network buffering methods compared in measuring a set of commonly used built environment measures (BEMs) and tested their performance on associations with physical activity outcomes. METHODS: An internationally-developed set of objective BEMs using three different spatial buffering techniques were used to evaluate the relative differences in resulting explanatory power on self-reported physical activity outcomes. BEMs were developed in five countries using 'sausage,' 'detailed-trimmed,' and 'detailed,' network buffers at a distance of 1 km around participant household addresses (n = 5883). RESULTS: BEM values were significantly different (p < 0.05) for 96% of sausage versus detailed-trimmed buffer comparisons and 89% of sausage versus detailed network buffer comparisons. Results showed that BEM coefficients in physical activity models did not differ significantly across buffering methods, and in most cases BEM associations with physical activity outcomes had the same level of statistical significance across buffer types. However, BEM coefficients differed in significance for 9% of the sausage versus detailed models, which may warrant further investigation. CONCLUSIONS: Results of this study inform the selection of spatial buffering methods to estimate physical activity outcomes using an internationally consistent set of BEMs. Using three different network-based buffering methods, the findings indicate significant variation among BEM values, however associations with physical activity outcomes were similar across each buffering technique. The study advances knowledge by presenting consistently assessed relationships between three different network buffer types and utilitarian travel, sedentary behavior, and leisure-oriented physical activity outcomes.

A spatio-temporal index for heat vulnerability assessment.

The public health consequences of extreme heat events are felt most intensely in metropolitan areas where population density is high and the presence of the urban heat island phenomenon exacerbates the potential for prolonged exposure. This research develops an approach to map potential heat stress on humans by combining temperature and relative humidity into an index of apparent temperature. We use ordinary kriging to generate hourly prediction maps describing apparent temperature across the Greater Toronto Area, Canada. Meteorological data were obtained from 65 locations for 6 days in 2008 when extreme heat alerts were issued for the City of Toronto. Apparent temperature and exposure duration were integrated in a single metric, humidex degree hours (HDH), and mapped. The results show a significant difference in apparent temperature between built and natural locations from 3 PM to 7 AM; this discrepancy was greatest at 12 AM where built locations had a mean of 2.8 index values larger, t(71) = 5.379, p < 0.001. Spatial trends in exposure to heat stress (apparent temperature, ≥ 30°C) show the downtown core of the City of Toronto and much of Mississauga (west of Toronto) as likely to experience hazardous levels of prolonged heat and humidity (HDH ≥ 72) during a heat alert. We recommend that public health officials use apparent temperature and exposure duration to develop spatially explicit heat vulnerability assessment tools; HDH is one approach that unites these risk factors into a single metric.

The unmet demand for walkability: Disparities between preferences and actual choices for residential environments in Toronto and Vancouver.

OBJECTIVES: Individual preferences for residential location, neighbourhood character and travel options are not always met. The availability and cost of housing and several other factors often require compromise. The primary objectives of this study were to examine neighbourhood preferences, quantify unmet demand for more walkable environments and explore associations between the built environment, travel behaviour and health after controlling for neighbourhood preference. METHODS: A web-based, visually oriented residential preference survey was conducted with 1,525 adults in the Greater Toronto Area and 1,223 adults in Metro Vancouver aged 25 and older (5.8% and 11.8% of total potential recruits, respectively). Participants were randomly selected from a pre-recruited panel across a range of objectively calculated walkability and income levels at the forward sortation area level. RESULTS: Depending on the neighbourhood design attribute, between 45% and 64% of residents in the cities of Toronto and Vancouver strongly preferred living in walkable settings, compared with between 6% and 15% who strongly preferred auto-oriented places. Of participants who perceived their current neighbourhood as very auto-oriented, between 11% and 20% of City of Toronto participants and 6% and 30% of City of Vancouver participants strongly preferred a very walkable neighbourhood. Residents of highly walkable neighbourhoods reported walking significantly more for utilitarian purposes, taking public transit more frequently and driving fewer kilometres. CONCLUSION: Strong preferences for walking and transit-supportive neighbourhoods exist in two of Canada's largest metropolitan regions, with considerable unmet demand observed for such environments. The findings provide evidence for policies that enable walkability and inform market analysis, planning and regulatory approaches that better align with the supply and demand of more walkable neighbourhood environments. Providing increased opportunities for active transportation can have positive impacts on health-enhancing behaviours.

Application of an evidence-based tool to evaluate health impacts of changes to the built environment.

OBJECTIVES: To create and apply an empirically based health and greenhouse gas (GHG) impact assessment tool linking detailed measures of walkability and regional accessibility with travel, physical activity, health indicators and GHG emissions. METHODS: Parcel land use and transportation system characteristics were calculated within a kilometre network buffer around each Toronto postal code. Built environment measures were linked with health and demographic characteristics from the Canadian Community Health Survey and travel behaviour from the Transportation Tomorrow Survey. Results were incorporated into an existing software tool and used to predict health-related indicators and GHG emissions for the Toronto West Don Lands Redevelopment. RESULTS: Walkability, regional accessibility, sidewalks, bike facilities and recreation facility access were positively associated with physical activity and negatively related to body weight, high blood pressure and transportation impacts. When applied to the West Don Lands, the software tool predicted a substantial shift from automobile use to walking, biking and transit. Walking and biking trips more than doubled, and transit trips increased by one third. Per capita automobile trips decreased by half, and vehicle kilometres travelled and GHG emissions decreased by 15% and 29%, respectively. CONCLUSION: The results presented are novel and among the first to link health outcomes with detailed built environment features in Canada. The resulting tool is the first of its kind in Canada. This tool can help policy-makers, land use and transportation planners, and health practitioners to evaluate built environment influences on health-related indicators and GHG emissions resulting from contrasting land use and transportation policies and actions.