Does urban greenness reduce loneliness and social isolation among Canadians? A cross-sectional study of middle-aged and older adults of the Canadian Longitudinal Study on Aging (CLSA)

OBJECTIVES

Urban greenness has been shown to confer many health benefits including reduced risks of chronic disease, depression, anxiety, and, in a limited number of studies, loneliness. In this first Canadian study on this topic, we investigated associations between residential surrounding greenness and loneliness and social isolation among older adults.

METHODS

This cross-sectional analysis of the Canadian Longitudinal Study on Aging included 26,811 urban participants between 45 and 86 years of age. The Normalized Difference Vegetation Index (NDVI), a measure of greenness, was assigned to participants' residential addresses using a buffer distance of 500 m. We evaluated associations between the NDVI and (i) self-reported loneliness using the Center for Epidemiological Studies Depression Scale, (ii) whether participants reported "feeling lonely living in the local area", and (iii) social isolation. Logistic regression models were used to characterize associations between greenness and loneliness/social isolation while adjusting for individual socio-economic and health behaviours.

RESULTS

Overall, 10.8% of participants perceived being lonely, while 6.5% reported "feeling lonely in their local area". Furthermore, 16.2% of participants were characterized as being socially isolated. In adjusted models, we observed no statistically significant difference (odds ratio (OR) = 0.99; 95% confidence interval (CI) 0.93-1.04) in self-reported loneliness in relation to an interquartile range (IQR) increase of NDVI (0.06). However, for the same change in greenness, there was a 15% (OR = 0.85; 95% CI 0.72-0.99) reduced risk for participants who strongly agreed with "feeling lonely living in the local area". For social isolation, for an IQR increase in the NDVI, we observed a 7% (OR = 0.93; 95% CI 0.88-0.97) reduction in prevalence.

CONCLUSION

Our findings suggest that urban greenness plays a role in reducing loneliness and social isolation among Canadian urbanites.

Neighborhood Fast-Food Environments and Hypertension in Canadian Adults

INTRODUCTION

Hypertension is a leading cause of cardiovascular disease and premature death worldwide. Neighborhoods characterized by a high proportion of fast-food outlets may also contribute to hypertension in residents; however, limited research has explored these associations. This cross-sectional study assessed the associations between neighborhood fast-food environments, measured hypertension, and self-reported hypertension.

METHODS

Data from 10,700 adults living in urban areas were obtained from six Canadian Health Measures Survey cycles (2007-2019). Each participant's blood pressure was measured at a mobile clinic six times. Measured hypertension was defined as having an average systolic blood pressure ≥140 or a diastolic blood pressure ≥90 mm Hg or being on blood pressure-lowering medication. Participants were also asked whether they had been diagnosed with high blood pressure or whether they take blood pressure-lowering medication (i.e., self-reported hypertension). The proportion of fast-food outlets relative to the sum of fast-food outlets and full-service restaurants in each participant's neighborhood was obtained from the Canadian Food Environment Dataset, and analyses were conducted in 2022.

RESULTS

The mean proportion of fast-food outlets was 23.3% (SD=26.8%). A one SD increase in the proportion of fast-food outlets was associated with higher odds of measured hypertension in the full sample (OR=1.17, 95% CI=1.05, 1.31) and in sex-specific models (women: OR=1.14, 95% CI=1.01, 1.29; men: OR=1.21, 95% CI=1.03, 1.43). Associations between the proportion of fast-food outlets and self-reported hypertension were inconclusive.

CONCLUSIONS

Findings suggest that reducing the proportion of fast-food restaurants in neighborhoods may be a factor that could help reduce hypertension rates.

Associations of free sugars from solid and liquid sources with cardiovascular disease: a retrospective cohort analysis

BACKGROUND

The World Health Organization recommends a 10% total energy (TE%) limit for free sugars (i.e., added sugars and naturally occurring sugars in fruit juice, honey, and syrups) based on evidence linking higher intakes with overweight and dental caries. Evidence for cardiovascular disease (CVD) is limited. Impacts may differ by sex, age group, and solid vs. liquid sources; liquids may stimulate more adverse CVD profiles (due to their rapid absorption in the body along along with triggering less satiety). We examined associations of consuming total free sugars ≥ 10 TE% with CVD within four sex and age-defined groups. Given roughly equal free sugar intakes from solid and liquid sources, we also evaluated source-specific associations of free sugars ≥ 5 TE% thresholds.

METHODS

In this retrospective cohort study, we estimated free sugars from 24-h dietary recall (Canadian Community Health Survey, 2004-2005) in relationship to nonfatal and fatal CVD (Discharge Abstract and Canadian Mortality Databases, 2004-2017; International Disease Classification-10 codes for ischemic heart disease and stroke) through multivariable Cox proportional hazards models adjusted for overweight/obesity, health behaviours, dietary factors, and food insecurity. We conducted analyses in separate models for men 55 to 75 years, women 55 to 75 years, men 35 to 55 years, and women 35 to 55 years. We dichotomized total free sugars at 10 TE% and source-specific free sugars at 5 TE%.

RESULTS

Men 55 to 75 years of age had 34% higher CVD hazards with intakes of free sugars from solid sources ≥ 5 TE% vs. below (adjusted HR 1.34, 95% CI 1.05- 1.70). The other three age and sex-specific groups did not demonstrate conclusive associations with CVD.

CONCLUSIONS

Our findings suggest that from a CVD prevention standpoint in men 55 to 75 years of age, there may be benefits from consuming less than 5 TE% as free sugars from solid sources.

Income inequality and population health: a political-economic research agenda

There is more than 30 years of research on relationships between income inequality and population health. In this article, we propose a research agenda with five recommendations for future research to refine existing knowledge and examine new questions. First, we recommend that future research prioritise analyses with broader time horizons, exploring multiple temporal aspects of the relationship. Second, we recommend expanding research on the effect of public expenditures on the inequality-health relationship. Third, we introduce a new area of inquiry focused on interactions between social mobility, income inequality and population health. Fourth, we argue the need to examine new perspectives on 21st century capitalism, specifically the population health impacts of inequality in income from capital (especially housing), in contrast to inequality in income from labour. Finally, we propose that this research broaden beyond all-cause mortality, to cause-specific mortality, avoidable mortality and subcategories thereof. We believe that such a research agenda is important for policy to respond to the changes following the COVID-19 pandemic.

An international comparative study of active living environments and hospitalization for Wales and Canada

Rationale: Previous studies indicate active living environments (ALEs) are associated with higher physical activity levels across different geographic contexts, and could lead to reductions in hospital burden. Both Wales UK and Canada have advanced data infrastructure that allows record linkage between survey data and administrative health information.

Objective

To assess the relationship between ALEs and hospitalization in Wales and Canada.

Methods

We performed a population-based comparison using individual-level survey data from the Welsh Health Survey (N = 9968) linked to the Patient Episode Database for Wales, and the Canadian Community Health Survey (N = 40,335) linked to the Discharge Abstract Database. Using equivalent protocols and open-source data for street networks, destinations, and residential density, we derived 5-class measures of the ALE for Wales and Canada (classed 1 through 5, considered least favourable to most favourable for active living, respectively). We evaluated relationships of ALEs to health, behaviours and hospitalization using multivariate regression (reference group was the lowest ALE class 1, considered least favourable for active living).

Results

For Canada, those living in the highest ALE class 5 had lower odds of all-cause hospitalization (OR 0.66, 95% CI 0.54 to 0.81; as compared to the lowest ALE class 1). In contrast, those living in the highest ALE class 5 in Wales had higher odds of all-cause hospitalization (OR 1.37, 95% CI 1.04 to 1.80). The relationship between ALEs and cardiometabolic hospitalization was inconclusive for Canada (OR 0.75, 95% CI 0.50 to 1.12), but we observed higher odds of cardiometabolic hospitalization for respondents living in higher ALE classes for Wales (OR 1.46, 95% CI 1.10 to 1.78; comparing ALE class 4 to ALE class 1).

Conclusion

Canadian respondents living in high ALE neighbourhoods that are understood to be favourable for active living had lower odds of all-cause hospitalization, whereas Welsh respondents living in high ALEs that were deemed favourable for active living exhibited higher odds of all-cause hospitalization. Environments which promote physical activity in one geographic context may not do so in another. There remains a need to identify relevant context-specific factors that encourage active living.

A Systematic Review and Narrative Synthesis of the Evolution of Adolescent and Young Adult Cannabis Consumption Before and After Legalization

PURPOSE

To systematically review evidence assessing the evolution of cannabis consumption before and after the implementation of non-medical cannabis legislation.

METHODS

MEDLINE, PubMED, PsycINFO, Scopus, and Web of Science were systematically searched for studies that examined change in cannabis consumption before and after nonmedical cannabis legislation. Data were tabulated by study design, levels of consumption, and individual subgroups. Data were analyzed using a narrative synthesis approach, considering study quality.

RESULTS

32 studies were included (11 higher quality and 21 lower quality). 40% of higher quality evidence supported an increase in postlegalization consumption (55% did not report a change and 5% reported a decrease). The increase was most evident for young adults (42% of higher quality evidence) and in the consumption in the past month (37% of higher quality evidence). There was limited supporting evidence for new users having grown in response to legalization. Based on subgroup analysis, the increase in postlegalization consumption was higher among women and those who engage in binge-drinking.

CONCLUSIONS

Higher quality evidence suggests an increase in adolescent past-month consumption of cannabis following legalization in several geographical jurisdictions. Consumption evolution prelegalization and postlegalization differed by age group and for young women and for binge drinkers. Consumption evolution differences suggest a variety of strategies might be required in efforts to lower public health impacts of cannabis consumption following legalization.

Does living near hospital obscure the association between active living environments and hospitalization?

Hospitals tend to be among the destinations that make densely populated, well-connected neighbourhoods more conducive to active living. In this study, we determined whether living near a hospital distorts the association between living in favourable ALEs and hospitalization for physical inactivity-related cardiometabolic diseases. We used a record linkage of 442,345 respondents of the Canadian Community Health Survey and their hospitalization records for cardiometabolic disease. We then assessed respondents' neighbourhoods using the Canadian Active Living Environments measure (Can-ALE), a measure based on ≥3-way intersection density, residential density, and points of interest. We then calculated the distance in kilometers between the centroids of respondents' assigned dissemination areas and the nearest user-contributed location for hospitals from OpenStreetMap. We monitored changes in estimates for the association between ALEs and odds of cardiometabolic disease hospitalization using a series of logistic regressions with indicator variables for distances to hospital of 500 meters to 10 kilometers. We found that living between 500 meters and six kilometers of a hospital and was associated with modestly higher odds of cardiometabolic hospitalization (OR 1.10, 95% CI 1.02 to 1.18 for 500 meters; OR 1.05, 95% CI 1.01 to 1.09 for six kilometers). Living in more favourable ALEs was associated with lower odds of hospitalization (OR 0.79, 95% CI 0.68 to 0.91; comparing the most favourable to least favourable ALEs). Effect estimates between more favourable ALEs and lower odds of hospitalization were marginally strengthened when living within 2-6 kilometers to a hospital was accounted for. This study demonstrates the importance of disentangling interrelated geographic factors and underlines the potential for built environments to elicit reductions in health care.

Increased urban greenness associated with improved mental health among middle-aged and older adults of the Canadian Longitudinal Study on Aging (CLSA)

OBJECTIVES

Some studies suggest that residential surrounding greenness is associated with improved mental health. Few of these studies have focussed on middle-aged and older adults, explored the modifying effects of social determinants of health, or accounted for the extent to which individuals interact with their neighbourhood environments.

METHODS

We analysed cross-sectional data collected from 26,811 urban participants of the Canadian Longitudinal Study of Aging who were between 45 and 86 years of age. Participants provided details on socioeconomic characteristics, health behaviours, and their frequency of neighbourhood interactions. The Normalized Difference Vegetation Index (NDVI), a measure of greenness, was assigned to participants' residential addresses at a buffer distance of 500 m. Four self-reported measures of mental health were considered: The Center for Epidemiologic Studies Depression Scale (CES-D-10; short scale), past diagnosis of clinical depression, perceptions of mental health, and the Satisfaction with Life Scale (SWLS). Regression models were used to describe associations between greenness and these outcomes, and spline models were fit to characterize the exposure-response function between greenness and CES-D-10 scores. Stratified analyses evaluated whether associations varied by sociodemographic status.

RESULTS

In adjusted models, we observed a 5% (Odds Ratio (OR) = 0.95; 95% CI = 0.90, 0.99) reduced odds of depressive symptoms in relation to an interquartile range increase of NDVI (0.06) within a 500 m buffer of the participant's residence. Similarly, we found an inverse association with a self-reported clinical diagnosis of depression (OR = 0.97; 95% CI = 0.92-1.01). Increases in surrounding greenness were associated with improved perceptions of mental health, and the SWLS. Our spline analyses found that beneficial effects between greenness and the CES-D-10 were strongest among those of lower income.

CONCLUSIONS

These findings suggest that residential greenness has mental health benefits, and that interventions to increase urban greenness can help reduce social inequalities in mental health.

A pan-Canadian dataset of neighbourhood retail food environment measures using Statistics Canada's Business Register

BACKGROUND

The objective of this study was to create the Canadian Food Environment Dataset (Can-FED) and to demonstrate its validity.

DATA AND METHODS

Food outlet data were extracted from Statistics Canada's Business Register (BR) in 2018. Retail food environment access measures (both absolute and relative measures) were calculated using network buffers around the centroid of 56,589 dissemination areas in Canada. A k-medians clustering approach was used to create categorical food environment variables that were easy to use and amenable to dissemination. Validity of the measures was assessed by comparing the food environment measures from Can-FED with measures created using Enhanced Points of Interest data by DMTI Spatial Inc. and data from a municipal health inspection list. Validity was also assessed by calculating the geographic variability in food environments across census metropolitan areas (CMAs) and assessing associations between CMA-level food environments and CMA-level health indicators.

RESULTS

Two versions of Can-FED were created: a researcher file that must be accessed within a secure Statistics Canada environment and a general-use file available online. Agreement between Can-FED food environment measures and those derived from a proprietary dataset and a municipal health inspection list ranged from r_s=0.28 for convenience store density and r_s=0.53 for restaurant density. At the CMA level, there is wide geographic variation in the food environment with evidence of patterning by health indicators.

INTERPRETATION

Can-FED is a valid and accessible dataset of pan-Canadian food environment measures that was created from the BR, a data source that has not been explored fully for health research.

Are school-based measures of walkability and greenness associated with modes of commuting to school? Findings from a student survey in Ontario, Canada

OBJECTIVES

In Canada, students are increasingly reliant on motorized vehicles to commute to school, and few meet the recommended overall physical activity guidelines. Infrastructure and built environments around schools may promote active commuting to and from school, thereby increasing physical activity. To date, few Canadian studies have examined this research question.

METHODS

This study is a cross-sectional analysis of 11,006 students, aged 11-20, who participated in the 2016/2017 Ontario Student Drug Use and Health Survey. The remote sensing-derived Normalized Difference Vegetation Index (NDVI), at a buffer of 500 m from the schools' locations, was used to characterize greenness, while the 2016 Canadian Active Living Environments (Can-ALE) measure was used for walkability. Students were asked about their mode of regular commuting to school, and to provide information on several socio-demographic variables. Multivariable logistic regression models were used to quantify associations between active commuting and greenness and the Can-ALE. The resulting odds ratios, and their 95% confidence intervals, were adjusted for a series of risk factors that were collected from the survey.

RESULTS

Overall, 21% of students reported active commuting (biking or walking) to school, and this prevalence decreased with increasing age. Students whose schools had higher Can-ALE scores were more likely to be active commuters. Specifically, the adjusted odds ratio (OR) of being an active commuter for schools in the highest quartile of the Can-ALE was 2.11 (95% CI = 1.64, 2.72) when compared with those in the lowest. For children, aged 11-14 years, who attended schools in high dwelling density areas, a higher odds of active commuting was observed among those in the upper quartile of greenness relative to the lowest (OR = 1.41; 95% CI = 0.92, 2.15). In contrast, for lower dwelling density areas, greenness was inversely associated with active commuting across all ages.

CONCLUSION

Our findings suggest that students attending schools with higher Can-ALE scores are more likely to actively commute to school, and that positive impacts of greenness on active commuting are evident only in younger children in more densely populated areas. Future studies should collect more detailed data on residential measures of the built environment, safety, distance between home and school, and mixed modes of commuting behaviours.

Active living environments, physical activity and premature cardiometabolic mortality in Canada: a nationwide cohort study

OBJECTIVE

To evaluate sex-specific and age-specific associations of active living environments (ALEs) with premature cardiometabolic mortality.

DESIGN

Population-based retrospective cohort study.

SETTING

Residential neighbourhoods (1000-metre circular buffers from the centroids of dissemination areas) across Canada for which the Canadian ALE Measure was derived, based on intersection density, points of interest and dwelling density.

PARTICIPANTS

249 420 survey respondents from an individual-level record linkage between the Canadian Community Health Survey (2000-2010) and the Canadian Mortality Database until 2011, comprised of older women (65-85 years), older men (65-81 years), middle-aged women (45-64 years) and middle-aged men (45-64 years).

PRIMARY OUTCOME MEASURES

Premature cardiometabolic mortality and average daily energy expenditure attributable to walking. Multivariable proportional hazards regression models were adjusted for age, educational attainment, dissemination area-level median income, smoking status, obesity, the presence of chronic conditions, season of survey response and survey cycle.

RESULTS

Survey respondents contributed a total of 1 451 913 person-years. Greater walking was observed in more favourable ALEs. Walking was associated with lower cardiometabolic death in all groups except for middle-aged men. Favourable ALEs conferred a 22% reduction in death from cardiometabolic causes (HR 0.78, 95% CI 0.63 to 0.97) for older women.

CONCLUSIONS

On average, people walk more in favourable ALEs, regardless of sex and age. With the exception of middle-aged men, walking is associated with lower premature cardiometabolic death. Older women living in neighbourhoods that favour active living live longer.

Moving to policy-amenable options for built environment research: The role of micro-scale neighborhood environment in promoting walking

BACKGROUND

Altering micro-scale features of neighborhoods (e.g., the presence and condition of benches, sidewalks, trees, crossing signals, walking paths) could be a relatively cost-effective method of creating environments that are conducive to physical activity. The Virtual Systematic Tool for Evaluating Pedestrian Streetscapes (Virtual-STEPS) was created to virtually audit the microscale environment of cities using Google Street View (GSV). The objective of this study was to evaluate the collective influence of items from the Virtual-STEPS tool on walking outcomes (utilitarian walking and walking for leisure), while accounting for self-selection of walkers into walking-friendly neighborhoods.

METHODS

Adults (N = 1403) were recruited from Montreal and Toronto from neighborhoods stratified by their level of macro-scale walking-friendliness and walking rates. The micro-scale environment of 5% of street segments from the selected neighborhoods was audited using the Virtual-STEPS tool and a micro-scale environment score was assigned. The scores were then linked to each respondent from the survey. A multilevel logistic regression analysis was used to model the relationship between the micro-scale environment score and odds of both utilitarian walking (i.e., walking for purpose such as to go shopping or go to work or school) and walking for leisure for at least 150 min per week, while accounting for environmental and demographic covariates as well as self-selection.

RESULTS

Micro-scale neighborhood features were associated with elevated odds of walking for leisure (OR: 1.14, CI: 1.04-1.25). The association between micro-scale neighborhood features and walking for utilitarian purposes was, however, inconclusive (OR: 1.01, CI: 0.90-1.13). On the other hand, macro-scale walk-friendliness was associated with elevated odds of walking for utilitarian purposes (OR: 2.01, CI:1.42-2.84) and the association between macro-scale features and leisure walking was inconclusive (OR: 1.02, CI: 0.78-1.34).

CONCLUSIONS

Our results imply that micro-scale features of neighborhoods collectively promote leisure walking but not necessarily utilitarian walking, even after accounting for self-selection. In contrast, macro-scale features may collectively promote utilitarian walking, but not leisure walking. Micro scale features of neighborhoods fall within the budget of local jurisdictions and our results suggest that jurisdictions that improve micro-scale features may expect increased leisure walking in populations.

Healthy built environment: Spatial patterns and relationships of multiple exposures and deprivation in Toronto, Montreal and Vancouver

BACKGROUND

Various aspects of the urban environment and neighbourhood socio-economic status interact with each other to affect health. Few studies to date have quantitatively assessed intersections of multiple urban environmental factors and their distribution across levels of deprivation.

OBJECTIVES

To explore the spatial patterns of urban environmental exposures within three large Canadian cities, assess how exposures are distributed across socio-economic deprivation gradients, and identify clusters of favourable or unfavourable environmental characteristics.

METHODS

We indexed nationally standardized estimates of active living friendliness (i.e. "walkability"), NO₂ air pollution, and greenness to 6-digit postal codes within the cities of Toronto, Montreal and Vancouver. We compared the distribution of within-city exposure tertiles across quintiles of material deprivation. Tertiles of each exposure were then overlaid with each other in order to identify potentially favorable (high walkability, low NO₂, high greenness) and unfavorable (low walkability, high NO₂, and low greenness) environments.

RESULTS

In all three cities, high walkability was more common in least deprived areas and less prevalent in highly deprived areas. We also generally saw a greater prevalence of postal codes with high vegetation indices and low NO₂ in areas with low deprivation, and a lower greenness prevalence and higher NO₂ concentrations in highly deprived areas, suggesting environmental inequity is occurring. Our study showed that relatively few postal codes were simultaneously characterized by desirable or undesirable walkability, NO₂and greenness tertiles.

DISCUSSION

Spatial analyses of multiple standardized urban environmental factors such as the ones presented in this manuscript can help refine municipal investments and policy priorities. This study illustrates a methodology to prioritize areas for interventions that increase active living and exposure to urban vegetation, as well as lower air pollution. Our results also highlight the importance of considering the intersections between the built environment and socio-economic status in city planning and urban public health decision-making.

The association between walkable neighbourhoods and physical activity across the lifespan

BACKGROUND

Walkability is positively associated with physical activity in adults. Walkability is more consistently associated with walking for transportation than recreational walking. The purpose of this study is to examine how the association between walkable neighbourhoods and physical activity varies by age and type of physical activity using a new Canadian walkability database.

DATA AND METHODS

The 2016 Canadian Active Living Environments (Can-ALE) database was attached to two cross-sectional health surveys: the Canadian Health Measures Survey (CHMS; 2009 to 2015) and the Canadian Community Health Survey (CCHS; 2015 to 2016). Physical activity was measured in the CHMS using the Actical accelerometer (n = 10,987; ages 3 to 79). Unorganized physical activity outside of school among children aged 3 to 11 was reported by parents in the CHMS (n = 4,030), and physical activity data by type (recreational, transportation-based, school-based, and household and occupational) was self-reported by respondents in the CCHS (n = 105,876; ages 12 and older).

RESULTS

Walkability was positively associated with accelerometer-measured moderate-to-vigorous physical activity in youth (p < 0.05), younger adults (p < 0.0001) and older adults (p < 0.05), while walkability was negatively associated with light physical activity in youth (ages 12 to 17) and older adults (ages 60 to 79) (p < 0.05). Walkability was positively associated with self-reported transportation-based physical activity in youth (p < 0.001) and adults of all ages (p < 0.0001). Walkability was negatively associated with parent-reported unorganized physical activity of children aged 5 to 11, and children living in the most walkable neighbourhoods accumulated 10 minutes of physical activity less-on average-than those living in the least walkable neighbourhoods.

DISCUSSION

The results of this study are consistent with previous studies indicating that walkability is more strongly associated with physical activity in adults than in children and that walkability is associated with transportation-based physical activity. Walkability is one of many built environment factors that may influence physical activity. More research is needed to identify and understand the built environment factors associated with physical activity in children and with recreational or leisure-time physical activity.

An examination of the associations between walkable neighbourhoods and obesity and self-rated health in Canadians

BACKGROUND

Two-thirds of Canadian adults and one-third of Canadian children and youth are overweight or obese. There is increased interest in identifying features of the built environment-such as walkability-that facilitate lifestyle habits associated with reduced obesity and improved health. The purpose of this study is to examine how the associations between walkability and both obesity and self-rated health vary by age in Canadians using a new walkability dataset.

DATA AND METHODS

The 2016 Canadian Active Living Environments (Can-ALE) database was attached to Canadian Health Measures Survey (CHMS; 2009 to 2015) data. Moderate-to-vigorous physical activity (MVPA), light physical activity (LPA) and step counts were measured in the CHMS using the Actical accelerometer (n = 10,852; ages 3 to 79). Body mass index (BMI) and waist circumference were measured in a mobile clinic. Self-rated general and mental health were assessed using a questionnaire.

RESULTS

The percentage of adults aged 40 to 59 classified as overweight or obese was 28 percentage points lower in the most walkable Can-ALE category than in the least walkable category (49.1% vs. 77.5%, p < 0.0125). There was a significant downward linear trend in measured BMI and waist circumference across Can-ALE categories (from least to most walkable) for adults aged 18 to 59, but not for children and youth or older adults aged 60 to 79. MVPA was a significant mediating factor in the association between the Can-ALE index and BMI in adults aged 40 to 79 (and in the waist circumference of respondents aged 40 to 59). Young adults (aged 18 to 39) were more likely than older adults (aged 60 to 79) to report very good or excellent general health as walkability increased.

DISCUSSION

Using a new and freely-available Canadian walkability index, this study observed a positive association between walkability and both measured obesity and self-rated general health in adults. Walkability is one of many built environment characteristics that should be considered when trying to understand the relative contribution of the built environment to a person's weight and overall health.

A pan-Canadian measure of active living environments using open data

BACKGROUND

Neighbourhood environments that support active living, such as walking or cycling for transportation, may decrease the burden of chronic conditions related to sedentary behaviour. Many measures exist to summarize features of communities that support active living, but few are pan-Canadian and none use open data sources that can be widely shared. This study reports the development and validation of a novel set of indicators of active living environments using open data that can be linked to national health surveys and can be used by local, regional or national governments for public health surveillance.

DATA AND METHODS

A Geographic Information System (GIS) was used to calculate a variety of measures of the connectivity, density and proximity to destinations for 56,589 dissemination areas (DAs) across Canada (2016 data). Pearson correlation coefficients were calculated to assess the association between each measure and the rates of walking to work and taking active transportation to work (a combination of walking, cycling and using public transportation) from census data. The active living environment measures selected for the final database were used to classify the DAs by the favourability of their active living environment into groups by k-medians clustering.

RESULTS

All measures were correlated with walking-to-work and active-transportation-to-work rates at the DA level, whether they were derived using proprietary or open data sources. Coverage of open data was consistent across Canadian regions. Three measures were selected for the Canadian Active Living Environments (Can-ALE) dataset based on the correlation analysis, but also on the principles of suitability for a variety of community sizes and openly available data: (1) three-way intersection density of roads and footpaths derived from OpenStreetMap (OSM), (2) weighted dwelling density derived from Statistics Canada dwelling counts and (3) points of interest derived from OSM. A measure of access to public transportation was added for the subset of DAs in larger urban areas and was strongly related to active-transportation-to-work rates. Active-transportation-to-work rates were graded, in steps, by the five Can-ALE groups derived from the cluster analysis, although walking-to-work rates exceeded the national average only in the most favourable active living environments.

DISCUSSION

Open data may be used to derive measures that characterize the active living environments of Canadian communities.

Neighbourhood retail food outlet access, diet and body mass index in Canada: a systematic review

INTRODUCTION

There is growing interest in the role of food environments in suboptimal diet and overweight and obesity. This review assesses the evidence for the link between the retail food environment, diet quality and body mass index (BMI) in the Canadian population.

METHODS

We conducted a systematic keyword search in two bibliometric databases. We tabulated proportions of conclusive associations for each outcome and exposure of interest. Absolute and relative measures of exposure to the food environment were compared and theoretical framing of the associations noted. We assessed two key methodological issues identified a priori-measurement of BMI, and validation of the underlying retail food environment data.

RESULTS

Seventeen studies were included in the review. There was little evidence of a food environment-diet quality relationship and modest evidence of a food environment-BMI relationship. Relative measures of the food environment were more often associated with an outcome in the expected direction than absolute measures, but many results were inconclusive. Most studies adopted ecological theoretical frameworks but methodologies were similar regardless of stated theoretical approaches. Self-reported BMI was common and there was no "gold standard" database of food outlets nor a consensus on best ways to validate the data.

CONCLUSION

There was limited evidence of a relationship between the food environment and diet quality, but stronger evidence of a relationship between the food environment and BMI for Canadians. Studies with broad geographic scope that adopt innovative methods to measure diet and health outcomes and use relative measures of the food environment derived in geographic information systems are warranted. Consensus on a gold standard food environment database and approaches to its validation would also advance the field.

Assessing the micro-scale environment using Google Street View: the Virtual Systematic Tool for Evaluating Pedestrian Streetscapes (Virtual-STEPS)

Background

Altering micro-scale features of neighborhood walkability (e.g., benches, sidewalks, and cues of social disorganization or crime) could be a relatively cost-effective method of creating environments that are conducive to active living. Traditionally, measuring the micro-scale environment has required researchers to perform observational audits. Technological advances have led to the development of virtual audits as alternatives to observational field audits with the enviable properties of cost-efficiency from elimination of travel time and increased safety for auditors. This study examined the reliability of the Virtual Systematic Tool for Evaluating Pedestrian Streetscapes (Virtual-STEPS), a Google Street View-based auditing tool specifically designed to remotely assess micro-scale characteristics of the built environment.

Methods

We created Virtual-STEPS, a tool with 40 items categorized into 6 domains (pedestrian infrastructure, traffic calming and streets, building characteristics, bicycling infrastructure, transit, and aesthetics). Items were selected based on their past abilities to predict active living and on their feasibility for a virtual auditing tool. Two raters performed virtual and field audits of street segments in Montreal neighborhoods stratified by the Walkscore that was used to determine the ‘walking-friendliness’ of a neighborhood. The reliability between virtual and field audits (n = 40), as well as inter-rater reliability (n = 60) were assessed using percent agreement, Cohen’s Kappa statistic, and the Intra-class Correlation Coefficient.

Results

Virtual audits and field audits (excluding travel time) took similar amounts of time to perform (9.8 versus 8.2 min). Percentage agreement between virtual and field audits, and for inter-rater agreement was 80% or more for the majority of items included in the Virtual-STEPS tool. There was high reliability between virtual and field audits with Kappa and ICC statistics indicating that 20 out of 40 (50.0%) items had almost perfect agreement and 13 (32.5%) items had substantial agreement. Inter-rater reliability was also high with 17 items (42.5%) with almost perfect agreement and 11 (27.5%) items with substantial agreement.

Conclusions

Virtual-STEPS is a reliable tool. Tools that measure the micro-scale environment are important because changing this environment could be a relatively cost-effective method of creating environments that are conducive to active living.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-7460-3) contains supplementary material, which is available to authorized users.

The planning and reporting of mixed methods studies on the built environment and health

Researchers examining the influence of the built environment on health are increasingly using mixed methods approaches. The use of more than one type of methodology to address a single research question is compelling in this field because researchers investigating the impact of the built environment on health have been faced with proposing solutions to a complex societal problem involving interacting systems and social uncertainties. Mixed methods studies can help researchers to gain a better understanding of the relationships that exist between humans and their environment by drawing on qualitative and quantitative methods. Mixed methods studies could also be instrumental for providing effective policy solutions. This is because they allow researchers to identify built environment determinants of health in a population of interest and to understand the social and cultural factors that might influence the uptake of an intervention by this population. The objective of this paper is to assist those conducting research on the built environment and health who may have little background in mixed methods. We provide an overview of mixed methods research designs and provide concrete techniques for the integration of diverse methods. We also discuss the recommendations for mixed methods research in the field of built environment - health research, drawing on specific examples from published studies. Reporting a research design and an integration strategy in mixed methods studies could help to strengthen our ability to gain new insights into the multidimensional nature of the relationship between the built environment and health.

The heat penalty of walkable neighbourhoods

"Walkability" or walking-friendliness is generally considered a favourable attribute of a neighbourhood that supports physical activity and improves health outcomes. Walkable neighbourhoods tend to have high-density infrastructure and relatively high amounts of concrete and pavement for sidewalks and streets, all of which can elevate local urban temperatures. The objective of this study was to assess whether there is a "heat penalty" associated with more walkable neighbourhoods in Montréal, Québec, Canada, using air temperature measurements taken in real time at street level during a heat event. The mean temperature of "Car-Dependent" neighbourhoods was 26.2 °C (95% CI 25.8, 26.6) whereas the mean temperature of "Walker's Paradise" neighbourhoods was 27.9 °C (95% CI 27.8, 28.1)-a difference of 1.7 °C (95% CI 1.3, 2.0). There was a strong association between higher walkability of Montréal neighbourhoods and elevated temperature (r = 0.61, p < 0.01); suggestive of a heat penalty for walkable neighbourhoods. Planning solutions that support increased walking-friendliness of neighbourhoods should consider simultaneous strategies to mitigate heat to reduce potential health consequences of the heat penalty.

Multiple non-climatic drivers of food insecurity reinforce climate change maladaptation trajectories among Peruvian Indigenous Shawi in the Amazon

BACKGROUND

Climate change is affecting food systems globally, with implications for food security, nutrition, and the health of human populations. There are limited data characterizing the current and future consequences of climate change on local food security for populations already experiencing poor nutritional indicators. Indigenous Amazonian populations have a high reported prevalence of nutritional deficiencies. This paper characterizes the food system of the Shawi of the Peruvian Amazon, climatic and non-climatic drivers of their food security vulnerability to climate change, and identifies potential maladaptation trajectories.

METHODS AND FINDINGS

Semi-structured interviews with key informants (n = 24), three photovoice workshops (n = 17 individuals), transect walks (n = 2), a food calendar exercise, and two community dissemination meetings (n = 30 individuals), were conducted within two Shawi communities in Balsapuerto District in the Peruvian Loreto region between June and September of 2014. The Shawi food system was based on three main food sub-systems (forest, farming and externally-sourced). Shawi reported collective, gendered, and emotional notions related to their food system activities. Climatic and non-climatic drivers of food security vulnerability among Shawi participants acted at proximal and distal levels, and mutually reinforced key maladaptation trajectories, including: 1) a growing population and natural resource degradation coupled with limited opportunities to increase incomes, and 2) a desire for education and deforestation reinforced by governmental social and food interventions.

CONCLUSION

A series of maladaptive trajectories have the potential to increase social and nutritional inequities for the Shawi. Transformational food security adaptation should include consideration of Indigenous perceptions and priorities, and should be part of Peruvian food and socioeconomic development policies.

Evaluating the Impact of Neighborhood Characteristics on Differences between Residential and Mobility-Based Exposures to Outdoor Air Pollution

Epidemiological studies often assign outdoor air pollution concentrations to residential locations without accounting for mobility patterns. In this study, we examined how neighborhood characteristics may influence differences in exposure assessments between outdoor residential concentrations and mobility-based exposures. To do this, we linked residential location and mobility data to exposure surfaces for NO₂, PM_2.5, and ultrafine particles in Montreal, Canada for 5452 people in 2016. Mobility data were collected using the MTL Trajet smartphone application (mean: 16 days/subject). Generalized additive models were used to identify important neighborhood predictors of differences between residential and mobility-based exposures and included residential distances to highways, traffic counts within 500 m of the residence, neighborhood walkability, median income, and unemployment rate. Final models including these parameters provided unbiased estimates of differences between residential and mobility-based exposures with small root-mean-square error values in 10-fold cross validation samples. In general, our findings suggest that differences between residential and mobility-based exposures are not evenly distributed across cities and are greater for pollutants with higher spatial variability like NO₂. It may be possible to use neighborhood characteristics to predict the magnitude and direction of this error to better understand its likely impact on risk estimates in epidemiological analyses.

Childbirth-Related Hospital Burden by Socioeconomic Status in a Universal Health Care Setting

INTRODUCTION

Hospital utilization varies across socioeconomic and demographic strata in Canada, a country with a universal health care system. Rates of adverse birth outcomes are known to differ among women of high and low socioeconomic status (SES), but less is known of the excess hospital burden related to SES over the course of childbirth across Canadian provinces.

OBJECTIVE

To examine length of stay and risk of hospitalization surrounding delivery, relative to women's socio-demographic characteristics.

METHODS

A population-based record linkage between the Canadian Community Health Survey (CCHS) years 2005-2011 and the Discharge Abstract Database (DAD) allowed the tracking of hospital utilization for linked survey respondents between 2005 and 2011. Hourly length of stay for delivery, risk of readmission, and risk of admission prior to delivery was modeled by socio-demographic factors, controlling for other clinical and individual-level characteristics.

RESULTS

There were 21,914 complete delivery records from 15,458 female CCHS respondents who agreed to link and share their information. Average length of stay (for both vaginal and Caesarian deliveries) dropped over the study period from 67.86 hours in 2005 to 59.37 hours in 2011. In multivariate analyses, women with the lowest income had on average, two-hour longer stays for vaginal delivery as compared to high-income women (IRR 1.04, 95% CI 1.00-1.08) and higher risk of admission prior to delivery (OR 1.43, CI 1.13-1.81). Low-income women, Aboriginal women and women living in rural areas were also at elevated risk for longer hospital stays and for hospital admission prior to delivery. There was no consistent socioeconomic patterning of hospital burden for Caesarian deliveries.

CONCLUSION

The length of hospital stays for childbirth has declined in Canada. Length of stay remains modestly longer, and risk of hospitalization in the perinatal period higher, for low income women, Aboriginal women and rural women. The absence of egregious income-related differences in hospital burden related to childbirth is reassuring for the equity goals of the Canadian health care system. The persistence of marginally longer, and in turn, costlier visits for low-income and Aboriginal women before and during delivery is, however, suggestive that resources targeted to the prenatal period might be highly cost-effective if they achieve population-wide reductions in length of stay and hospitalization in the perinatal period.

Steps, moderate-to-vigorous physical activity, and cardiometabolic profiles

The relative benefits of meeting the current moderate-to-vigorous intensity physical activity (MVPA) and active step count recommendations are unknown. Using robust linear regressions, we compared cardiometabolic marker differences (blood pressure, lipid levels, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), hemoglobin A1C, C-reactive protein (CRP), and body mass index (BMI)) across MVPA (150min/week) and step (10,000 steps/day) thresholds and between step categories (low active: 5000 to 7499, somewhat active: 7500 to 9999, and active: ≥10,000 steps/day vs. inactive: <5000 steps/day) in approximately 6000 Canadian adults (41.5years, SD 14.9). Differences across MVPA and step thresholds were similar but additional benefits were observed for BMI and A1C for the MVPA target (i.e., above vs. below 150min/week MVPA: -1.02kg/m² (95% Confidence Interval [CI] -1.25 to -0.80) and -0.04% (95% CI -0.06 to -0.02); above vs. below ≥10,000 steps/day: -0.40kg/m² (95% CI -0.63 to -0.16) and 0.01% (95% CI -0.01 to 0.03)). In terms of steps categories, the greatest incremental improvement was achieved at the somewhat active threshold (e.g., somewhat active vs. inactive: -0.90kg/m², 95% CI -1.28 to -0.53; low active vs. inactive: -0.36kg/m², 95% CI -0.73 to 0.02). Additional benefits beyond the 10,000 step/day threshold were limited (e.g., -0.93kg/m², 95% CI -1.30 to -0.57). Given that most benefits to markers of cardiometabolic health were at the ≥7500 step/day threshold and that there was some additional benefit across the 150min/week MVPA threshold compared to a 10,000 steps/day threshold, we suggest aiming for ≥7500 steps/day and then advancing to a 150min/MVPA goal.

Lexical neutrality in environmental health research: Reflections on the term walkability

Neighbourhood environments have important implications for human health. In this piece, we reflect on the environments and health literature and argue that precise use of language is critical for acknowledging the complex and multifaceted influence that neighbourhood environments may have on physical activity and physical activity-related outcomes. Specifically, we argue that the term “neighbourhood walkability”, commonly used in the neighbourhoods and health literature, constrains recognition of the breadth of influence that neighbourhood environments might have on a variety of physical activity behaviours. The term draws attention to a single type of physical activity and implies that a universal association exists when in fact the literature is quite mixed. To maintain neutrality in this area of research, we suggest that researchers adopt the term “neighbourhood physical activity environments” for collective measures of neighbourhood attributes that they wish to study in relation to physical activity behaviours or physical activity-related health outcomes.

Neighbourhood walkability and home neighbourhood-based physical activity: an observational study of adults with type 2 diabetes

Background

Converging international evidence suggests that diabetes incidence is lower among adults living in more walkable neighbourhoods. The association between walkability and physical activity (PA), the presumed mediator of this relationship, has not been carefully examined in adults with type 2 diabetes. We investigated the associations of walkability with total PA occurring within home neighbourhoods and overall PA, irrespective of location.

Methods

Participants (n = 97; 59.5 ± 10.5 years) were recruited through clinics in Montreal (QC, Canada) and wore a GPS-accelerometer device for 7 days. Total PA was expressed as the total Vector of the Dynamic Body Acceleration. PA location was determined using a Global Positioning System (GPS) device (SIRF IV chip). Walkability (street connectivity, land use mix, population density) was assessed using Geographical Information Systems software. The cross-sectional associations between walkability and location-based PA were estimated using robust linear regressions adjusted for age, body mass index, sex, university education, season, car access, residential self-selection, and wear-time.

Results

A one standard deviation (SD) increment in walkability was associated with 10.4 % of a SD increment in neighbourhood-based PA (95 % confidence interval (CI) 1.2, 19.7) – equivalent to 165 more steps/day (95 % 19, 312). Car access emerged as an important predictor of neighbourhood-based PA (Not having car access: 38.6 % of a SD increment in neighbourhood-based PA, 95 % CI 17.9, 59.3). Neither walkability nor car access were conclusively associated with overall PA.

Conclusions

Higher neighbourhood walkability is associated with higher home neighbourhood-based PA but not with higher overall PA. Other factors will need to be leveraged to facilitate meaningful increases in overall PA among adults with type 2 diabetes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3603-y) contains supplementary material, which is available to authorized users.

Plasmodium falciparum malaria parasitaemia among indigenous Batwa and non-indigenous communities of Kanungu district, Uganda

BACKGROUND

The indigenous Batwa of southwestern Uganda are among the most highly impoverished populations in Uganda, yet there is negligible research on the prevalence of malaria in this population. Plasmodium falciparum malaria parasitaemia prevalence was estimated in an indigenous Batwa and a non-indigenous neighbouring population, and an exploration of modifiable risk factors was carried out to identify potential entry points for intervention. Additionally, evidence of zooprophylaxis was assessed, hypothesizing that livestock ownership may play a role in malaria risk.

METHODS

Two cross-sectional surveys of Batwa and non-Batwa communities were carried out in Kanungu District, Uganda in July 2013 and April 2014 based on a census of adult Batwa and a two-stage systematic random sample of adult non-Batwa in ten Local Councils where Batwa settlements are located. A community-based questionnaire and antigen rapid diagnostic test for P. falciparum were carried out in the cross-sectional health surveys. A multivariable logistic regression model was built to identify risk factors associated with positive malaria diagnostic test. A subset analysis of livestock owners tested for zooprophylaxis.

RESULTS

Batwa experienced higher prevalence of malaria parasitaemia than non-Batwa (9.35 versus 4.45 %, respectively) with over twice the odds of infection (OR 2.21, 95 % CI 1.23-3.98). Extreme poverty (OR 1.96, 95 % CI 0.98-3.94) and having an iron sheet roof (OR 2.54, 95 % CI 0.96-6.72) increased the odds of infection in both Batwa and non-Batwa. Controlling for ethnicity, wealth, and bed net ownership, keeping animals inside the home at night decreased the odds of parasitaemia among livestock owners (OR 0.29, 95 % CI 0.09-0.94).

CONCLUSION

A health disparity exists between indigenous Batwa and non-indigenous community members with Batwa having higher prevalence of malaria relative to non-Batwa. Poverty was associated with increased odds of malaria infection for both groups. Findings suggest that open eaves and gaps in housing materials associated with iron sheet roofing represent a modifiable risk factor for malaria, and may facilitate mosquito house entry; larger sample sizes will be required to confirm this finding. Evidence for possible zooprophylaxis was observed among livestock owners in this population for those who sheltered animals inside the home at night.

Neighbourhood Walkability and Daily Steps in Adults with Type 2 Diabetes

Introduction

There is evidence that greater neighbourhood walkability (i.e., neighbourhoods with more amenities and well-connected streets) is associated with higher levels of total walking in Europe and in Asia, but it remains unclear if this association holds in the Canadian context and in chronic disease populations. We examined the relationships of different walkability measures to biosensor-assessed total walking (i.e., steps/day) in adults with type 2 diabetes living in Montreal (QC, Canada).

Materials and Methods

Participants (60.5±10.4 years; 48.1% women) were recruited through McGill University-affiliated clinics (June 2006 to May 2008). Steps/day were assessed once per season for one year with pedometers. Neighbourhood walkability was evaluated through participant reports, in-field audits, Geographic Information Systems (GIS)-derived measures, and the Walk Score^®. Relationships between walkability and daily steps were estimated using Bayesian longitudinal hierarchical linear regression models (n = 131).

Results

Participants who reported living in the most compared to the least walkable neighbourhoods completed 1345 more steps/day (95% Credible Interval: 718, 1976; Quartiles 4 versus 1). Those living in the most compared to the least walkable neighbourhoods (based on GIS-derived walkability) completed 606 more steps per day (95% CrI: 8, 1203). No statistically significant associations with steps were observed for audit-assessed walkability or the Walk Score^®.

Conclusions

Adults with type 2 diabetes who perceived their neighbourhoods as more walkable accumulated more daily steps. This suggests that knowledge of local neighborhood features that enhance walking is a meaningful predictor of higher levels of walking and an important component of neighbourhood walkability.

Neighborhood Walkability and Body Mass Index Trajectories: Longitudinal Study of Canadians

OBJECTIVES

To assess the impact of neighborhood walkability on body mass index (BMI) trajectories of urban Canadians.

METHODS

Data are from Canada's National Population Health Survey (n = 2935; biannual assessments 1994-2006). We measured walkability with the Walk Score. We modeled body mass index (BMI, defined as weight in kilograms divided by the square of height in meters [kg/m(2)]) trajectories as a function of Walk Score and sociodemographic and behavioral covariates with growth curve models and fixed-effects regression models.

RESULTS

In men, BMI increased annually by an average of 0.13 kg/m(2) (95% confidence interval [CI] = 0.11, 0.14) over the 12 years of follow-up. Moving to a high-walkable neighborhood (2 or more Walk Score quartiles higher) decreased BMI trajectories for men by approximately 1 kg/m(2) (95% CI = -1.16, -0.17). Moving to a low-walkable neighborhood increased BMI for men by approximately 0.45 kg/m(2) (95% CI = 0.01, 0.89). There was no detectable influence of neighborhood walkability on body weight for women.

CONCLUSIONS

Our study of a large sample of urban Canadians followed for 12 years confirms that neighborhood walkability influences BMI trajectories for men, and may be influential in curtailing male age-related weight gain.

Neighbourhood walkability, daily steps and utilitarian walking in Canadian adults

OBJECTIVES

To estimate the associations of neighbourhood walkability (based on Geographic Information System (GIS)-derived measures of street connectivity, land use mix, and population density and the Walk Score) with self-reported utilitarian walking and accelerometer-assessed daily steps in Canadian adults.

DESIGN

A cross-sectional analysis of data collected as part of the Canadian Health Measures Survey (2007-2009).

SETTING

Home neighbourhoods (500 m polygonal street network buffers around the centroid of the participant's postal code) located in Atlantic Canada, Québec, Ontario, the Prairies and British Columbia.

PARTICIPANTS

5605 individuals participated in the survey. 3727 adults (≥18 years) completed a computer-assisted interview and attended a mobile clinic assessment. Analyses were based on those who had complete exposure, outcome and covariate data (n=2949).

MAIN EXPOSURE MEASURES

GIS-derived walkability (based on land use mix, street connectivity and population density); Walk Score.

MAIN OUTCOME MEASURES

Self-reported utilitarian walking; accelerometer-assessed daily steps.

RESULTS

No important relationship was observed between neighbourhood walkability and daily steps. Participants who reported more utilitarian walking, however, accumulated more steps (<1 h/week: 6613 steps/day, 95% CI 6251 to 6975; 1 to 5 h/week: 6768 steps/day, 95% CI 6420 to 7117; ≥6 h/week: 7391 steps/day, 95% CI 6972 to 7811). There was a positive graded association between walkability and odds of walking ≥1 h/week for utilitarian purposes (eg, Q4 vs Q1 of GIS-derived walkability: OR=1.66, 95% CI 1.31 to 2.11; Q3 vs Q1: OR=1.41, 95% CI 1.14 to 1.76; Q2 vs Q1: OR=1.13, 95% CI 0.91 to 1.39) independent of age, sex, body mass index, married/common law status, annual household income, having children in the household, immigrant status, mood disorder, perceived health, ever smoker and season.

CONCLUSIONS

Contrary to expectations, living in more walkable Canadian neighbourhoods was not associated with more total walking. Utilitarian walking and daily steps were, however, correlated and walkability demonstrated a positive graded relationship with utilitarian walking.

A systematic, realist review of zooprophylaxis for malaria control

BACKGROUND

Integrated vector management (IVM) is recommended as a sustainable approach to malaria control. IVM consists of combining vector control methods based on scientific evidence to maximize efficacy and cost-effectiveness while minimizing negative impacts, such as insecticide resistance and environmental damage. Zooprophylaxis has been identified as a possible component of IVM as livestock may draw mosquitoes away from humans, decreasing human-vector contact and malaria transmission. It is possible, however, that livestock may actually draw mosquitoes to humans, increasing malaria transmission (zoopotentiation). The goal of this paper is to take a realist approach to a systematic review of peer-reviewed literature to understand the contexts under which zooprophylaxis or zoopotentiation occur.

METHODS

Three electronic databases were searched using the keywords 'zooprophylaxis' and 'zoopotentiation', and forward and backward citation tracking employed, to identify relevant articles. Only empirical, peer-reviewed articles were included. Critical appraisal was applied to articles retained for full review.

RESULTS

Twenty empirical studies met inclusion criteria after critical appraisal. A range of experimental and observational study designs were reported. Outcome measures included human malaria infection and mosquito feeding behaviour. Two key factors were consistently associated with zooprophylaxis and zoopotentiation: the characteristics of the local mosquito vector, and the location of livestock relative to human sleeping quarters. These associations were modified by the use of bed nets and socio-economic factors.

DISCUSSION

This review suggests that malaria risk is reduced (zooprophylaxis) in areas where predominant mosquito species do not prefer human hosts, where livestock are kept at a distance from human sleeping quarters at night, and where mosquito nets or other protective measures are used. Zoopotentiation occurs where livestock are housed within or near human sleeping quarters at night and where mosquito species prefer human hosts.

CONCLUSION

The evidence suggests that zooprophylaxis could be part of an effective strategy to reduce malaria transmission under specific ecological and geographical conditions. The current scientific evidence base is inconclusive on understanding the role of socio-economic factors, optimal distance between livestock and human sleeping quarters, and the effect of animal species and number on zooprophylaxis.

Associations between neighbourhood walkability and daily steps in adults: a systematic review and meta-analysis

Background

Higher street connectivity, land use mix and residential density (collectively referred to as neighbourhood walkability) have been linked to higher levels of walking. The objective of our study was to summarize the current body of knowledge on the association between neighbourhood walkability and biosensor-assessed daily steps in adults.

Methods

We conducted a systematic search of PubMed, SCOPUS, and Embase (Ovid) for articles published prior to May 2014 on the association between walkability (based on Geographic Information Systems-derived street connectivity, land use mix, and/or residential density) and daily steps (pedometer or accelerometer-assessed) in adults. The mean differences in daily steps between adults living in high versus low walkable neighbourhoods were pooled across studies using a Bayesian hierarchical model.

Results

The search strategy yielded 8,744 unique abstracts. Thirty of these underwent full article review of which six met the inclusion criteria. Four of these studies were conducted in Europe and two were conducted in Asia. A meta-analysis of four of these six studies indicates that participants living in high compared to low walkable neighbourhoods accumulate 766 more steps per day (95 % credible interval 250, 1271). This accounts for approximately 8 % of recommended daily steps.

Conclusions

The results of European and Asian studies support the hypothesis that higher neighbourhood walkability is associated with higher levels of biosensor-assessed walking in adults. More studies on this association are needed in North America.

The association between socio-demographic marginalization and plasma glucose levels at diagnosis of gestational diabetes

AIMS

We examined the association between socio-demographic marginalization and plasma glucose levels at diagnosis of gestational diabetes in a multi-ethnic and socio-economically diverse patient group.

METHODS

Medical charts at a Toronto gestational diabetes clinic were reviewed for women with a recorded pregnancy between 1 March 2006 and 26 April 2011. One-hour 50-g glucose challenge test values and postal code data were abstracted. Postal codes were merged with 2006 Canadian census data to compute neighbourhood-level ethnic concentration (% recent immigrants, % visible minorities) and material deprivation (% low education, % low income, single-parent households). We compared women in the highest neighbourhood quintiles for both ethnic concentration and material deprivation with all other women to explore an association between marginalization and diagnostic glucose levels. Multivariate regression models of glucose challenge test values and insulin prescription were adjusted for age, prior gestational diabetes, parity and diabetes family history.

RESULTS

Among 531 patients with complete glucose challenge test data (mean 11.94 mmol/l, sd 1.83), those in the most marginalized neighbourhoods had 0.43 mmol/l higher glucose challenge test values (95% CI 0.08-0.78) compared with the rest of the study population. Other factors associated with higher glucose challenge test values were prior gestational diabetes (0.59 mmol/l increment, 95% CI 0.19-0.99) and diabetes family history (0.32 mmol/l increment, 95% CI -0.01 to 0.66). Each additional 1 mmol/l glucose challenge test result was associated with an increased likelihood of being prescribed insulin (odds ratio 1.33, 95% CI 1.17-1.51).

CONCLUSIONS

Women living in the most materially deprived and ethnically concentrated neighbourhoods have higher glucose levels at diagnosis of gestational diabetes. They may need close monitoring for timely initiation of insulin.

Neighbourhood immigrant concentration and hospitalization: a multilevel analysis of cardiovascular-related admissions in Ontario using linked data

OBJECTIVE

To assess the influence of neighbourhood immigrant concentration on cardiovascular-disease-related hospitalizations in Canada (CVDH), while adjusting for individual-level immigrant status and socio-economic indicators at individual and neighbourhood levels.

METHODS

Data were from the 2006 Canadian Census linked to the hospital Discharge Abstract Data (DAD) for the province of Ontario. Adults (n=1,459,950) aged ≥18 years at baseline and grouped by place of birth (Canada, China, South Asia, Europe, and other) were followed between Census Day May 16, 2006 and March 31, 2008. Information on CVDH was obtained from the DAD, while that on immigration and socio-economic indicators was obtained from the Census. The analysis used multilevel logistic regression.

RESULTS

Unadjusted results showed that CVDH was significantly lower among people living in neighbourhoods with medium and high immigrant concentration. Neighbourhood immigrant concentration tended to have no independent effect on CVDH after adjustment for individual-level immigrant status. Immigrants were less likely to experience CVDH irrespective of their country of birth. However, cross-level interaction showed that neighbourhood immigrant concentration provided additional protection to individual-level immigrant status against CVDH for most female immigrant groups, but only for South Asian males.

CONCLUSION

This study resulted from the first-ever linkage of census data to hospitalization data in Canada. It is also the first Canadian study to report on neighbourhood variation and the effect of immigrant concentration on CVDH. The study shows that understanding immigrant health requires both individual and neighbourhood approaches, and a consideration of country of origin.

Physical activity matters: associations among body mass index, physical activity, and health-related quality of life trajectories over 10 years

BACKGROUND

The objective of this study was to assess the associations among body mass index (BMI), leisure time physical activity (LTPA) and health-related quality of life (HRQL) trajectories among adults.

METHODS

Self-reported data were drawn from the Canadian National Population Health Survey, with respondents being interviewed every 2 years between 1996-97 and 2006-07. Using growth curve modeling, HRQL trajectories for individuals aged 18 and over were associated with measures of BMI and LTPA. Growth models were constructed separately for males and females.

RESULTS

Findings suggested that, for males, BMI categories had little impact on baseline HRQL, and no impact on the rate of change in HRQL. Among women, higher BMI categories were associated with significantly lower baseline HRQL. However, BMI had no impact on the rate of change of HRQL. Conversely, for both men and women and regardless of BMI category, LTPA had significant impacts on baseline HRQL, as well as the rate of change in HRQL. Individuals who were inactive or sedentary had much steeper declines in HRQL as they aged, as compared with individuals who were active in their leisure time.

CONCLUSIONS

The results underscore the importance of LTPA in shaping trajectories of HRQL.

A call for caution and transparency in the calculation of land use mix: measurement bias in the estimation of associations between land use mix and physical activity

There is evidence that land use mix based on the Shannon (1948) entropy formula may be misspecified in some studies. The aim of this study was to quantify the bias arising from this misspecification. Spatial coordinates were obtained from Statistics Canada for 9348 unique point locations. Five hundred-metre polygon-based network buffers were drawn around each coordinate (ArcGIS 10.1). Land use mix was calculated for each buffer using the true and misspecified land use mix formulas. Linear regression models were used to estimate the associations between a simulated dataset of daily steps and the true and misspecified measures. Misspecification of the land use mix formula resulted in a systematic underestimation of the true association by 26.4% (95% CI 25.8-27.0%). To minimize measurement bias in future studies, researchers are encouraged to use a constant definition of N in the denominator of the Shannon entropy formula.

How do neighborhoods affect depression outcomes? A realist review and a call for the examination of causal pathways

PURPOSE

This realist review seeks to elucidate the modifiable causal pathways through which neighborhoods affect depressive symptoms in adult populations.

METHODS

Studies were identified using Medline, PubMed, PsycInfo, Geobase, and Web of Science databases, and chosen using reproducible selection criteria and systematic critical appraisal.

RESULTS

A total of 14 longitudinal studies, published between 2003 and 2011, were included. Eleven of the articles observed a significant relationship between depression and at least one of the following neighborhood-level variables: neighborhood deprivation, disorder, instability, and social ties. Proposed modifiable pathways linking neighborhood characteristics and depression include: (1) the level of neighborhood-based stress that is placed on individuals, (2) the formation and strength of protective and supportive social networks, (3) the level of resiliency to negative affectivity and stress, (4) the perceptions of the esthetic and form of residential space, and (5) the sense of control and agency in place of residence. These pathways represent potential areas for future research and intervention.

CONCLUSIONS

Further research requires a more systematic use of longitudinal design and a diversity of physical and social environmental measures. Interventions aimed at improving affective resiliency need to be tested.

The association between alcohol use and long-term care placement among older Canadians: a 14-year population-based study

Studies have shown that moderate alcohol use confers protection against some of the dominant predictors of long-term care placement, including diminished cognitive functioning, physical disability, and injury. But little is known about the association between alcohol use and the likelihood of placement in long-term care facilities. A nationally representative sample of 5404 community-dwelling Canadians ages 50 years and older at baseline (1994/95) was obtained from the longitudinal National Population Health Survey. Alcohol use categories were developed based on the quantity and frequency of use in the 12 months before the interview. Cox proportional hazards models were used to estimate the association between alcohol use at baseline and subsequent placement in long-term care facilities after adjusting for covariates measured at baseline. During the 14-year follow-up period, 14% of lifetime abstainers, 10% of former drinkers, 7% of infrequent drinkers, 4% of moderate drinkers, and 3% of heavy drinkers were placed in long-term care facilities. Furthermore, the multivariate analysis revealed that abstainers, former drinkers, and infrequent drinkers were more than twice as likely to be placed in long-term care as moderate drinkers. Moderate drinking was protective against placement in long-term care facilities even after adjusting for an array of well-known confounders. The strong protective effect of moderate alcohol use on long-term care entry is likely due to a complex mix of physical, cognitive and psychosocial health factors.

A review of protective factors and causal mechanisms that enhance the mental health of Indigenous Circumpolar youth

OBJECTIVES

To review the protective factors and causal mechanisms which promote and enhance Indigenous youth mental health in the Circumpolar North.

STUDY DESIGN

A systematic literature review of peer-reviewed English-language research was conducted to systematically examine the protective factors and causal mechanisms which promote and enhance Indigenous youth mental health in the Circumpolar North.

METHODS

This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, with elements of a realist review. From 160 records identified in the initial search of 3 databases, 15 met the inclusion criteria and were retained for full review. Data were extracted using a codebook to organize and synthesize relevant information from the articles.

RESULTS

More than 40 protective factors at the individual, family, and community levels were identified as enhancing Indigenous youth mental health. These included practicing and holding traditional knowledge and skills, the desire to be useful and to contribute meaningfully to one's community, having positive role models, and believing in one's self. Broadly, protective factors at the family and community levels were identified as positively creating and impacting one's social environment, which interacts with factors at the individual level to enhance resilience. An emphasis on the roles of cultural and land-based activities, history, and language, as well as on the importance of social and family supports, also emerged throughout the literature. More than 40 protective factors at the individual, family, and community levels were identified as enhancing Indigenous youth mental health. These included practicing and holding traditional knowledge and skills, the desire to be useful and to contribute meaningfully to one's community, having positive role models, and believing in one's self. Broadly, protective factors at the family and community levels were identified as positively creating and impacting one's social environment, which interacts with factors at the individual level to enhance resilience. An emphasis on the roles of cultural and land-based activities, history, and language, as well as on the importance of social and family supports, also emerged throughout the literature.

CONCLUSIONS

Healthy communities and families foster and support youth who are resilient to mental health challenges and able to adapt and cope with multiple stressors, be they social, economic, or environmental. Creating opportunities and environments where youth can successfully navigate challenges and enhance their resilience can in turn contribute to fostering healthy Circumpolar communities. Looking at the role of new social media in the way youth communicate and interact is one way of understanding how to create such opportunities. Youth perspectives of mental health programmes are crucial to developing appropriate mental health support and meaningful engagement of youth can inform locally appropriate and culturally relevant mental health resources, programmes and community resilience strategies.

Achieving recommended daily physical activity levels through commuting by public transportation: unpacking individual and contextual influences

This paper estimates the amount of daily walking associated with using public transportation in a large metropolitan area and examines individual and contextual characteristics associated with walking distances. Total walking distance to and from transit was calculated from a travel diary survey for 6913 individuals. Multilevel regression modelling was used to examine the underlying factors associated with walking to public transportation. The physical activity benefits of public transportation varied along gender and socio-economic lines. Recommended minutes of daily physical activity can be achieved for public transportation users, especially train users living in affluent suburbs.

Traffic-related air pollution and prostate cancer risk: a case-control study in Montreal, Canada

OBJECTIVES

There is a paucity of information on environmental risk factors for prostate cancer. We conducted a case-control study in Montreal to estimate associations with exposure to ground-level nitrogen dioxide (NO2), a marker for traffic-related air pollution.

METHODS

Cases were 803 men with incident prostate cancer, ≤75 years of age, and diagnosed across all French hospitals in Montreal. Concurrently, 969 controls were drawn from electoral lists of French-speaking individuals residing in the same electoral districts as the cases and frequency-matched by age. Concentrations of NO2 were measured across Montreal in 2005-2006. We developed a land use regression model to predict concentrations of NO2 across Montreal for 2006. These estimates were back-extrapolated to 1996. Estimates were linked to residential addresses at the time of diagnosis or interview. Unconditional logistic regression was used, adjusting for potential confounding variables.

RESULTS

For each increase of 5 parts per billion of NO2, as estimated from the original land use regression model in 2006, the OR5ppb adjusted for personal factors was 1.44 (95% CI 1.21 to 1.73). Adding in contextual factors attenuated the OR5ppb to 1.27 (95% CI 1.03 to 1.58). One method for back-extrapolating concentrations of NO2 to 1996 (about 10 years before the index date) gave the following OR5ppb: 1.41 (95% CI 1.24 to 1.62) when personal factors were included, and 1.30 (95% CI 1.11 to 1.52) when contextual factors were added.

CONCLUSIONS

Exposure to ambient concentrations of NO2 at the current address was associated with an increased risk of prostate cancer. This novel finding requires replication.

A spatial analysis of individual- and neighborhood-level determinants of malaria incidence in adults, Ontario, Canada

Imported malaria cases in adults are strongly patterned by neighborhood economic and immigration levels.

Malaria, once endemic in Canada, is now restricted to imported cases. Imported malaria in Canada has not been examined recently in the context of increased international mobility, which may influence incidence of imported and autochthonous cases. Surveillance of imported cases can highlight high-risk populations and help target prevention and control measures. To identify geographic and individual determinants of malaria incidence in Ontario, Canada, we conducted a descriptive spatial analysis. We then compared characteristics of case-patients and controls. Case-patients were significantly more likely to be male and live in low-income neighborhoods that had a higher proportion of residents who had emigrated from malaria-endemic regions. This method’s usefulness in clarifying the local patterns of imported malaria in Ontario shows its potential to help identify areas and populations at highest risk for imported and emerging infectious disease.

Trajectories of health-related quality of life by socio-economic status in a nationally representative Canadian cohort

BACKGROUND

Mortality and morbidity have been shown to follow a 'social gradient' in Canada and many other countries around the world. Comparatively little, however, is known about whether ageing amplifies, diminishes or sustains socio-economic inequalities in health.

METHODS

Growth curve analysis of seven cycles of the Canadian National Population Health Survey (n=13,682) for adults aged 20 and older at baseline (1994/95). The outcome of interest is the Health Utilities Index Mark 3, a measure of health-related quality of life (HRQL). Models include the deceased so as not to present overly optimistic HRQL values. Socio-economic position is measured separately by household-size-adjusted income and highest level of education attained.

RESULTS

HRQL is consistently highest for the most affluent and the most highly educated men and women, and is lower, in turn, for middle and lower income and education groups. HRQL declines with age for both men and women. The rate of the decline in HRQL, however, was related neither to income nor to education for men, suggesting stability in the social gradient in HRQL over time for men. There was a sharper decline in HRQL for upper-middle and highest-income groups for women than for the poorest women.

CONCLUSION

HRQL is graded by both income and education in Canadian men and women. The grading of HRQL by social position appears to be 'set' in early adulthood and is stable through mid- and later life.

Bodyweight, gender, and quality of life: a population-based longitudinal study

PURPOSE

The objective of the paper is to describe trajectories of health-related quality of life (HRQL) associated with categories of body mass index (BMI): underweight, normal weight, overweight, obese class I, and obese classes II and III.

METHODS

Data come from the longitudinal Canadian National Population Health Survey. Analyses are based on data for 3,864 men and 4,745 women who were 40+ in 1998/1999 and followed through 2006/2007. HRQL was measured with the Health Utilities Index Mark 3. Multi-level growth modeling was used.

RESULTS

HRQL declined with age. For men, there was a large HRQL decrement for being underweight; trajectories for all other BMI categories were very similar. For women being underweight was associated with higher HRQL at younger ages but lower at older ages. Otherwise, for women, HRQL was ordered from highest to lowest: normal, overweight, obese class I, and obese classes II and III.

CONCLUSIONS

Given that excess weight is a risk factor for mortality and the development of chronic conditions, the HRQL results for men are surprising. The HRQL results for women may reflect both the importance of body image on mental health and the health effects of excess weight.

Psychological distress among immigrants and visible minorities in Canada: a contextual analysis

BACKGROUND

Immigrants to Canada are less likely to report depression compared with the non-immigrant population. This healthy migrant effect has not so far been explained by demographic and socioeconomic determinants of health.

AIM

The present study examined whether the psychological health advantage of immigrants varied across Canadian health regions and investigated the hypothesis of immigrant density as a determinant of immigrant mental health advantage.

METHODS

Data from the 2000-2001 Canadian Community Health Survey were used to build multi-level models estimating variation in depression within and between health regions by immigrant/visible minority status.

RESULTS

Immigrant and visible minority residents were less likely to experience depression compared with the general population. Depression varied across health regions and the extent of variation was greater for visible minorities. The likelihood of depression decreased with increasing percentage of immigrants in the region among visible minority participants but not among whites.

CONCLUSIONS

The protection against depression afforded by immigrant and visible minority status in Canada appears to depend on contextual factors, notably the percentage of immigrants in the region. Future work should seek to better characterize the experiences of visible minorities in different settings.