An application of the edge effect in measuring accessibility to multiple food retailer types in southwestern Ontario, Canada

Food environment research in Canada: a rapid review of methodologies and measures deployed between 2010 and 2021

Numerous research methodologies have been used to examine food environments. Existing reviews synthesizing food environment measures have examined a limited number of domains or settings and none have specifically targeted Canada. This rapid review aimed to 1) map research methodologies and measures that have been used to assess food environments; 2) examine what food environment dimensions and equity related-factors have been assessed; and 3) identify research gaps and priorities to guide future research. A systematic search of primary articles evaluating the Canadian food environment in a real-world setting was conducted. Publications in English or French published in peer-reviewed journals between January 1 2010 and June 17 2021 and indexed in Web of Science, CAB Abstracts and Ovid MEDLINE were considered. The search strategy adapted an internationally-adopted food environment monitoring framework covering 7 domains (Food Marketing; Labelling; Prices; Provision; Composition; Retail; and Trade and Investment). The final sample included 220 articles. Overall, Trade and Investment (1%, n = 2), Labelling (7%, n = 15) and, to a lesser extent, Prices (14%, n = 30) were the least studied domains in Canada. Among Provision articles, healthcare (2%, n = 1) settings were underrepresented compared to school (67%, n = 28) and recreation and sport (24%, n = 10) settings, as was the food service industry (14%, n = 6) compared to grocery stores (86%, n = 36) in the Composition domain. The study identified a vast selection of measures employed in Canada overall and within single domains. Equity-related factors were only examined in half of articles (n = 108), mostly related to Retail (n = 81). A number of gaps remain that prevent a holistic and systems-level analysis of food environments in Canada. As Canada continues to implement policies to improve the quality of food environments in order to improve dietary patterns, targeted research to address identified gaps and harmonize methods across studies will help evaluate policy impact over time.

Applicability of the Socioecological Model for Understanding and Reducing Consumption of Ultra-Processed Foods in Canada

Ultra-processed foods (UPFs) have become a major contributor to the diets of Canadians, with a recent report from Statistics Canada suggesting Canadians are consuming almost one-half of their calories from UPFs. Research has linked UPF consumption with increased risk for chronic diseases such as cardiovascular disease and type 2 diabetes, among others. This paper sought to investigate the popularity of UPFs, particularly among children and teens, utilizing the socioecological model as a framework to illustrate how influences at multiple levels (i.e., public policy, organizational, community, interpersonal, and individual) have played a role in the proliferation of UPFs. Evidence from previous studies is used to identify how factors at different levels may influence UPF consumption and discuss potential strategies for reducing UPF consumption. To meaningfully reduce UPF consumption among Canadians, all levels should be considered, with the goal of creating a healthier Canadian population.

A Vanishing Food Infrastructure: The Closure of Food Outlets in Flint in a Pandemic Era

Most food access studies focus on large cities, examine traditional grocery stores, and only consider operational food outlets. This siloed approach exposes a gap in food access literature. Therefore, as a part of our assessment of Flint’s food landscape, we examined closed food outlets in the city and surrounding townships. We investigated the relationship between the racial composition of census tracts and the number and type of defunct food outlets identified. We used Data Axle to collect and verify data on open and closed food outlets between September 2020 and December 2021. We made a final verification of the food outlet closures in June 2022. We used ArcGIS 10.8.1 and SPSS Version 28 to map and analyze the data. We used negative binomial regression models to determine differences in the likelihood of having an additional closed food outlet in census tracts with low and high percentages of Black residents. We also investigated the relationship between a census tract’s median income and the likelihood of having an additional closed food outlet. There were 173 closed food outlets; 81 were in Flint, and 92 were in surrounding townships. The most frequently closed food outlets were restaurants; they accounted for 45.1% of the closures. The mean number of closed food venues in census tracts where less than 40% of the residents were Black was 1.5. The mean was similar in census tracts where 40% or more of the residents were Black; it was 1.6. This difference was not significant. However, the median income of a census tract was a significant predictor of the likelihood of having an additional closed food outlet. Every one-thousand-dollar increase in median income resulted in a 2% less likelihood of having an additional closed food outlet. The results of this study show that there is more to the food landscape of a city than its operational food outlets. Focusing exclusively on active food outlets does not accurately depict a city's food infrastructure.

Incorporating Exercise Efficiency to Evaluate the Accessibility and Capacity of Medical Resources in Tibet, China

Accessibility and capacity of medical resources are key for the health care and emergency response, while the efficiency of the medical resources is very much limited by hypoxia in Tibet, China. Through introducing exercise efficiency, this study explores the accessibility of township residence to county-ship medical resources in Tibet using weighted mean travel time (WMT), and evaluates the medical capacity accordingly. The results show that: 1) the average travel time of township residence to county-level hospital is around 2 h by motor vehicle in Tibet. More than half of the population can not reach the county-ship hospital within 1 h, 33.24% of the population can not reach within 2 h, and 3.75% of the population can not reach within 6 h. 2) When considering the catchment of the medical resources and the population size, the WMT of the county-ship medical resources ranges from 0.25 h to 10.92 h. 3) After adjusted by travel time and exercise efficiency, the county-ship medical capacity became more unequal, with 38 out of 74 counties could not meet the national guideline of 1.8 medical beds per 1000. 4) In total, there are 17 counties with good WMT and sufficient medical resources, while 13 counties having very high WMT and low capacity of medical resources in Tibet. In the end, suggestions on medical resources relocation and to improve the capacity are provided. This study provides a method to incorporate exercise efficiency to access the accessibility and evaluate medical capacity that can be applied in high altitude ranges.

ELECTRONIC SUPPLEMENTARY MATERIAL

Supplementary material is available in the online version of this article at 10.1007/s11769-022-1321-1.

The Changing Landscape of Food Deserts and Swamps over More than a Decade in Flanders, Belgium

Food deserts and swamps have previously been mostly studied in Anglo-Saxon countries such as the USA and Great Britain. This research is one of the first studies to map food deserts and swamps in a mainland European, densely populated but heavily fragmented region such as Flanders. The evolution of food deserts and swamps between 2008 and 2020 was assessed. Special focus was given to areas where high numbers of elderly, young people and/or families with low income live. Food deserts were calculated based on supermarket access within 1000 m and bus stop availability, while food swamps were calculated using the Modified Food Environment Retail Index. The main cause behind the formation of food deserts in Flanders is its rapidly aging population. Food deserts with a higher number of older people increased from 2.5% to 3.1% of the residential area between 2008 and 2020, housing 2.2% and 2.8% of the population, respectively. Although the area that could become a food desert in the future due to these sociospatial and demographic evolutions is large, food deserts are currently a relatively small problem in Flanders in comparison to the widespread existence of food swamps. Unhealthy retailers outnumbered healthy retailers in 74% of residential areas in 2020, housing 88.2% of the population. These food swamps create an environment where unhealthy food choices predominate. Residential areas with a higher number of elderly people, young people and families with low incomes had healthier food environments than Flanders as a whole, because these areas are mostly found in dense urban centers where the ratio of healthy food retailers to all retailers is higher. This research showed that food deserts and swamps could be a growing problem in European regions with a high population density that experience the high pressures of competing land uses.

The quantity and composition of household food waste during the COVID-19 pandemic: A direct measurement study in Canada

The COVID-19 pandemic may have amplified the environmental, social, and economic implications of household food waste. A better understanding of household food wasting during the pandemic is needed to improve the management of waste and develop best practices for municipal waste management programs under crisis circumstances. A waste composition study was undertaken with 100 single-family households across the city of London, Ontario, Canada to determine the quantity and composition of household food waste disposed in June 2020, during the first wave of the COVID-19 pandemic. This study examines how household demographic, socioeconomic, and neighbourhood food environment characteristics influence household food wasting. On average, each household sent 2.81 kg of food waste to landfill per week, of which 52% was classified as avoidable food waste and 48% as unavoidable food waste. The quantity and composition of household food waste was found to be strongly influenced by the number of people and children in a household, and somewhat influenced by socioeconomic factors and neighbourhood food environment characteristics, including the availability, density, and proximity of retail food outlets.

Food Retail Network Spatial Matching and Urban Planning Policy Implications: The Case of Beijing, China

Food is the core of urban daily life and socio-economic activities but is rarely the focus of urban planning. The spatial layout of food retail outlets is important for optimizing the urban food system, improving land resource allocation, and encouraging healthy food consumption. Based on food retail POI data, this study employed kernel density estimation, road network centrality, spatial autocorrelation analysis, and locational entropy to analyze the spatial characteristics of supermarkets, produce markets, and small stores in an urban center in Beijing, and explored street coupling and supply-demand matching. The results indicated that within the study area: (1) supermarkets had an obvious “core-periphery” distribution, produce markets had a polycentric distribution, and small stores had a relatively uniform distribution; (2) road network centrality indices revealed a differentiated multi-core-edge distribution; (3) streets with high locational entropy values for supermarkets and produce markets were mostly concentrated in the central area, whereas the matching distribution of small stores was relatively balanced. From the perspective of urban planning, policy implications are proposed based on spatial and social equity, urban-rural differences, population structure and distribution status, and a resilient supply chain. The study findings have practical significance for guiding the development of urban food systems in a healthy, just, and sustainable direction, as well as rational urban land planning.

Association of community types and features in a case-control analysis of new onset type 2 diabetes across a diverse geography in Pennsylvania

OBJECTIVES

To evaluate associations of community types and features with new onset type 2 diabetes in diverse communities. Understanding the location and scale of geographic disparities can lead to community-level interventions.

DESIGN

Nested case-control study within the open dynamic cohort of health system patients.

SETTING

Large, integrated health system in 37 counties in central and northeastern Pennsylvania, USA.

PARTICIPANTS AND ANALYSIS

We used electronic health records to identify persons with new-onset type 2 diabetes from 2008 to 2016 (n=15 888). Persons with diabetes were age, sex and year matched (1:5) to persons without diabetes (n=79 435). We used generalised estimating equations to control for individual-level confounding variables, accounting for clustering of persons within communities. Communities were defined as (1) townships, boroughs and city census tracts; (2) urbanised area (large metro), urban cluster (small cities and towns) and rural; (3) combination of the first two; and (4) county. Community socioeconomic deprivation and greenness were evaluated alone and in models stratified by community types.

RESULTS

Borough and city census tract residence (vs townships) were associated (OR (95% CI)) with higher odds of type 2 diabetes (1.10 (1.04 to 1.16) and 1.34 (1.25 to 1.44), respectively). Urbanised areas (vs rural) also had increased odds of type 2 diabetes (1.14 (1.08 to 1.21)). In the combined definition, the strongest associations (vs townships in rural areas) were city census tracts in urban clusters (1.41 (1.22 to 1.62)) and city census tracts in urbanised areas (1.33 (1.22 to 1.45)). Higher community socioeconomic deprivation and lower greenness were each associated with increased odds.

CONCLUSIONS

Urban residence was associated with higher odds of type 2 diabetes than for other areas. Higher community socioeconomic deprivation in city census tracts and lower greenness in all community types were also associated with type 2 diabetes.

Linking historical discriminatory housing patterns to the contemporary food environment in Baltimore

Food access literature links disinvested communities with poor food access. Similarly, links are made between discriminatory housing practices and contemporary investment. Less work has examined the relationship between housing practices and food environment disparities. Our central premise is that these practices create distinctions in food environment quality, and that these disparities may have implications for food system advocacy and policymaking. In this paper, we link an objective food environment assessment with a spatial database highlighting redlining, blockbusting, and gentrification in Baltimore, Maryland, USA. Standard socioeconomic and housing characteristics are used to control for race, income, and housing composition in a multivariate regression analysis. Our findings highlight that blockbusting-rather than redlining-most strongly shapes poor food access. Redlining and gentrification, meanwhile, are associated with better food access. These findings raise important points about future policy discussions, which should instead be focused on ameliorating more contemporary patterns of housing inequality.

Elderly Sustainable Mobility: Scientific Paper Review

The number of elderly people as a proportion of the world’s population is growing significantly. Special attention to the accessibility and mobility requirements of this group is needed. The contribution of this paper is a review of travel patterns, mode preferences, infrastructure solutions, accessibility indices, mode choice models and datasets as they relate to elderly mobility. Key findings highlight the role of residential location characteristics in shaping elderly travel patterns, helping to explain why research on elderly travel has largely relied on case studies to date. The review also summarizes a range of indices that have been developed to measure public transport and walking accessibility among the elderly, including distance and time-based methods. Future research should consider the dominance of private transport in facilitating elderly mobility and its implications for cities experiencing an aging population.

How Neighbourhood Food Environments and a Pay-as-You-Throw (PAYT) Waste Program Impact Household Food Waste Disposal in the City of Toronto

Household food waste has negative, and largely unnecessary, environmental, social and economic impacts. A better understanding of current household food waste disposal is needed to help develop and implement effective interventions to reduce food wasting. A four-season waste characterization study was undertaken with 200 single-family households across eight neighbourhoods in Toronto, Ontario, Canada. The City of Toronto provides residents with a pay-as-you-throw (PAYT) waste program that includes a choice of four garbage cart sizes (Small [S], Medium [M], Large [L], Extra Large [XL]), with increasing annual user fees ($18.00–$411.00 CAD), as well as a green cart (organic waste) and blue cart (recycling). On average, each household disposed 4.22 kg/week of total food waste, 69.90% of which was disposed in the green cart, and disposal increased significantly (p = 0.03) by garbage cart size to L but not XL garbage carts. Of this total, 61.78% consisted of avoidable food waste, annually valued at $630.00–$847.00 CAD/household. Toronto’s PAYT waste program has been effective at diverting food waste into the green cart but not at reducing its generation. Higher median incomes were positively correlated, while higher neighbourhood dwelling and population density were negatively correlated, with total and avoidable food waste disposal. Regression analyses explained 40–67% of the variance in total avoidable food waste disposal. Higher supermarket density and distance to healthier food outlets were associated with more, while dwelling density was related to less, total and avoidable food waste disposal. Distance to fast food restaurants and less healthy food outlet density were both negatively associated with avoidable food waste disposal in the garbage and green cart, respectively. Avoidable food waste reduction interventions could include increasing garbage cart fees, weight-based PAYT, or messaging to households on the monetary value of avoidable food waste, and working with food retailers to improve how households shop for their food.

Healthy and unhealthy food environments are linked with neighbourhood socio-economic disadvantage: an innovative geospatial approach to understanding food access inequities

Objective:

This study examined the separate relationships between socio-economic disadvantage and the density of multiple types of food outlets, and relationships between socio-economic disadvantage and composite food environment indices.

Design:

Cross-sectional data were analysed using geospatial kernel density techniques. Food outlet data included convenience stores, discount stores, fast-food and fast casual restaurants, and grocery stores. Controlling for urbanicity and race/ethnicity, multivariate linear regression was used to examine the relationships between socio-economic disadvantage and density of food outlets.

Setting:

This study occurred in a large Southeastern US county containing 255 census block groups with a total population of 474 266, of which 77·1 % was Non-Hispanic White, the median household income was $48 886 and 15·0 % of residents lived below 125 % of the federal poverty line.

Participants:

The unit of analysis was block groups; all data about neighbourhood socio-economic disadvantage and food outlets were publicly available.

Results:

As block group socio-economic disadvantage increased, so too did access to all types of food outlets. The total food environment index, calculated as the ratio of unhealthy food outlets to all food outlets, decreased as block group disadvantage increased.

Conclusions:

Those who reside in more disadvantaged block groups have greater access to both healthy and unhealthy food outlets. The density of unhealthy establishments was greater in more disadvantaged areas; however, because of having greater access to grocery stores, disadvantaged populations have less obesogenic total food environments. Structural changes are needed to reduce access to unhealthy food outlets to ensure environmental injustice and reduce obesity risk.

Service deserts and service oases: Utilizing geographic information systems to evaluate service availability for individuals with autism spectrum disorder

LAY ABSTRACT

Autism spectrum disorder and co-occurring symptoms often require lifelong services. However, access to autism spectrum disorder services is hindered by a lack of available autism spectrum disorder providers. We utilized geographic information systems methods to map autism spectrum disorder provider locations in Michigan. We hypothesized that (1) fewer providers would be located in less versus more populated areas; (2) neighborhoods with low versus high socioeconomic status would have fewer autism spectrum disorder providers; and (3) an interaction would be found between population and socioeconomic status such that neighborhoods with low socioeconomic status and high population would have few available autism spectrum disorder providers. We compiled a list of autism spectrum disorder providers in Michigan, geocoded the location of providers, and used network analysis to assess autism spectrum disorder service availability in relation to population distribution, socioeconomic disadvantage, urbanicity, and immobility. Individuals in rural neighborhoods had fewer available autism spectrum disorder providers than individuals in suburban and urban neighborhoods. In addition, neighborhoods with greater socioeconomic status disadvantage had fewer autism spectrum disorder providers available. Finally, wealthier suburbs had good provider availability while few providers were available in poorer, urban neighborhoods. Knowing autism spectrum disorder providers' availability, and neighborhoods that are particularly poorly serviced, presents the opportunity to utilize evidence-based dissemination and implementation strategies that promote increased autism spectrum disorder providers for underserved individuals.

Using Zoning as a Public Health Tool to Reduce Oversaturation of Alcohol Outlets: an Examination of the Effects of the New "300 Foot Rule" on Packaged Goods Stores in a Mid-Atlantic City

The oversaturation of alcohol outlets can have disastrous public health consequences. The goal of this study was to evaluate the potential impact of new zoning legislation, TransForm Baltimore on locations of alcohol outlets. More specifically, the study sought to determine the effect of the new zoning code on the potential redistribution of alcohol outlets and also provide empirical support for the need to actively monitor redistribution of outlets to avoid further inequitable oversaturation in disadvantaged neighborhoods. Data on off-premise alcohol outlets (e.g., packaged goods stores) were obtained from the Board of Liquor License Commissioners for Baltimore City. The alcohol outlets were geocoded and assigned to zoning parcels. Churches and schools were also geocoded. The alcohol outlets were also assigned to census tracts to calculate socioeconomic statuses. One hundred seventy-two of the 263 off-premise packaged goods stores (PGS) were in violation of the new zoning law. TransForm will reduce the land parcels available to alcohol outlets by 27.2%. Areas containing non-conforming PGS were more likely to have a higher percentage of Black residents, single parent-families, unemployment, household poverty, and vacancy compared to Baltimore City averages and areas without non-conforming PGS. Planning enforcement efforts need to accompany related laws to prevent/reduce overconcentration of PGS in disadvantaged neighborhoods.

A Geospatial Analysis of Access to Ethnic Food Retailers in Two Michigan Cities: Investigating the Importance of Outlet Type within Active Travel Neighborhoods

To date, the research that examines food accessibility has tended to ignore ethnic food outlets. This void leaves us with a limited understanding of how such food stores may, or may not, impact food security. The study discussed herein addressed this by conducting a geospatial assessment of ethnic food outlet accessibility in two U.S. cities: Flint and Grand Rapids, Michigan. We used Geographic Information Systems (GIS) tools to create a revealed accessibility index for each food outlet, and used the index to determine access within active travel service areas. We utilized an ordinary least squares regression (OLS), and two local models: spatial autoregression (SAR) and geographically weighted regression (GWR) to enhance our understanding of global and localized relationships between outlet accessibility and type (while controlling for known covariates). The results show that the local models outperformed (R² max = 0.938) the OLS model. The study found that there was reduced access to ethnic restaurants in all service areas of Grand Rapids. However, in Flint, we observed this association in the bicycling areas only. Also notable were the influences that demographic characteristics had on access in each city. Ultimately, the findings tell us that nuanced planning and policy approaches are needed in order to promote greater access to ethnic food outlets and reduce overall food insecurity.

Measuring Rural Food Environments for Local Action in Australia: A Systematic Critical Synthesis Review

Poor diet is a significant contributor to obesity and chronic disease. With all being more prevalent in rural than urban Australia, modifying the food environment is a potential intervention point to improve the health of rural populations. This review examined the applicability of measurement tools used in rural food environment research for rural Australia. Six electronic databases were searched for peer-reviewed literature, published in English between 2006 and 2018, including at least one objective measure of the Community or Consumer Food Environment in a rural or mixed rural/urban context. One-hundred and seventy-seven papers were returned after removal of duplicates, with a final review of 25. Most studies were cross-sectional, with one intervention study of quasi-experimental design. Nine studies employed a conceptual model; there was considerable variability in tools used; and few described psychometric testing. The most common attribute measured was price, followed by available healthy options. The findings of this review do not offer a suite of ‘gold standard’ measurement tools known to be reliable, valid and sensitive to change to assess the community or consumer food environments in rural Australian towns. However, recommendations are proposed to progress this important area of research within a rural context.

A comparative analysis of the restaurant consumer food environment in Rochester (NY, USA) and London (ON, Canada): assessing children's menus by neighbourhood socio-economic characteristics

OBJECTIVE

To assess restaurant children's menus for content and nutritional quality; and to investigate the relationship between the restaurant consumer food environment for children and neighbourhood-level socio-economic characteristics within and between one Canadian city and one US city.

DESIGN

Cross-sectional observational study.

SETTING

London, ON, Canada and Rochester, NY, USA.ParticipantsRestaurant children's menus were assessed, scored and compared using the Children's Menu Assessment tool. We quantified neighbourhood accessibility to restaurants by calculating 800 m road-network buffers around the centroid of each city census block and created a new Neighbourhood Restaurant Quality Index for Children (NRQI-C) comprising the sum of restaurant menu scores divided by the total number of restaurants within each area. After weighting by population, we examined associations between NRQI-C and neighbourhood socio-economic characteristics using correlations and multiple regression analyses.

RESULTS

Nutritional quality of children's menus was greater, on average, in Rochester compared with London. Only one variable remained significant in the regression analyses for both cities: proportion of visible minorities had a positive effect on neighbourhood NRQI-C scores in London, whereas the reverse was true in Rochester.

CONCLUSIONS

Results suggest the presence of a socio-economic disparity within Rochester, where children in more disadvantaged areas have poorer access to better nutritional quality restaurant choices. In London, results suggest an inverse relationship across the city where children in more disadvantaged areas have better access to better nutritional quality restaurant choices. Given these disparate results, research on restaurant nutritional quality for children requires additional consideration.

Urban foodscape trends: Disparities in healthy food access in Chicago, 2007-2014

We investigated changes in supermarket access in Chicago between 2007 and 2014, spanning The Great Recession, which we hypothesized worsened local food inequity. We mapped the average street network distance to the nearest supermarket across census tracts in 2007, 2011, and 2014, and identified spatial clusters of persistently low, high or changing access over time. Although the total number of supermarkets increased city-wide, extremely low food access areas in segregated, low income regions did not benefit. Among black and socioeconomically disadvantaged residents of Chicago, access to healthy food is persistently poor and worsened in some areas following recent economic shocks.

Examining community and consumer food environments for children: An urban-suburban-rural comparison in Southwestern Ontario

The aim of this study is to evaluate how retail food environments for children in the City of London and Middlesex County, Ontario, Canada, vary according to level of urbanicity and level of socioeconomic distress. Urbanicity in this study is defined as a neighbourhood's designation as urban, suburban, or rural. We assessed community food environments (e.g., the type, location, and accessibility of food outlets) using 800m and 1600m network buffers (school zones) around all public and private elementary schools, and we calculated and compared density of junk food opportunities (JFO) (e.g., fast food and full-service restaurants, grocery stores, and convenience stores) within each school zone in urban, suburban and rural settings. The study also assessed consumer food environments (e.g., the price, promotion, placement, and availability of healthy options and nutrition information) through restaurant children's menu audits using the Children's Menu Assessment tool. Results suggest JFO density is greater around elementary schools in areas with higher levels of socioeconomic distress and urbanicity, while urbanicity is also associated with greater use of branded marketing and inclusion of an unhealthy dessert on children's menus.

Diving into the consumer nutrition environment: A Bayesian spatial factor analysis of neighborhood restaurant environment

Neighborhood restaurant environment (NRE) plays a vital role in shaping residents' eating behaviors. While NRE 'healthfulness' is a multi-facet concept, most studies evaluate it based only on restaurant type, thus largely ignoring variations of in-restaurant features. In the few studies that do account for such features, healthfulness scores are simply averaged over accessible restaurants, thereby concealing any uncertainty that attributed to neighborhoods' size or spatial correlation. To address these limitations, this paper presents a Bayesian Spatial Factor Analysis for assessing NRE healthfulness in the city of Kitchener, Canada. Several in-restaurant characteristics are included. By treating NRE healthfulness as a spatially correlated latent variable, the adopted modeling approach can: (i) identify specific indicators most relevant to NRE healthfulness, (ii) provide healthfulness estimates for neighborhoods without accessible restaurants, and (iii) readily quantify uncertainties in the healthfulness index. Implications of the analysis for intervention program development and community food planning are discussed.

Does the edge effect impact on the measure of spatial accessibility to healthcare providers?

BACKGROUND

Spatial accessibility indices are increasingly applied when investigating inequalities in health. Although most studies are making mentions of potential errors caused by the edge effect, many acknowledge having neglected to consider this concern by establishing spatial analyses within a finite region, settling for hypothesizing that accessibility to facilities will be under-reported. Our study seeks to assess the effect of edge on the accuracy of defining healthcare provider access by comparing healthcare provider accessibility accounting or not for the edge effect, in a real-world application.

METHODS

This study was carried out in the department of Nord, France. The statistical unit we use is the French census block known as 'IRIS' (Ilot Regroupé pour l'Information Statistique), defined by the National Institute of Statistics and Economic Studies. The geographical accessibility indicator used is the "Index of Spatial Accessibility" (ISA), based on the E2SFCA algorithm. We calculated ISA for the pregnant women population by selecting three types of healthcare providers: general practitioners, gynecologists and midwives. We compared ISA variation when accounting or not edge effect in urban and rural zones. The GIS method was then employed to determine global and local autocorrelation. Lastly, we compared the relationship between socioeconomic distress index and ISA, when accounting or not for the edge effect, to fully evaluate its impact.

RESULTS

The results revealed that on average ISA when offer and demand beyond the boundary were included is slightly below ISA when not accounting for the edge effect, and we found that the IRIS value was more likely to deteriorate than improve. Moreover, edge effect impact can vary widely by health provider type. There is greater variability within the rural IRIS group than within the urban IRIS group. We found a positive correlation between socioeconomic distress variables and composite ISA. Spatial analysis results (such as Moran's spatial autocorrelation index and local indicators of spatial autocorrelation) are not really impacted.

CONCLUSION

Our research has revealed minor accessibility variation when edge effect has been considered in a French context. No general statement can be set up because intensity of impact varies according to healthcare provider type, territorial organization and methodology used to measure the accessibility to healthcare. Additional researches are required in order to distinguish what findings are specific to a territory and others common to different countries. It constitute a promising direction to determine more precisely healthcare shortage areas and then to fight against social health inequalities.

Gardening in the desert: a spatial optimization approach to locating gardens in rapidly expanding urban environments

BACKGROUND

Food access is a global issue, and for this reason, a wealth of studies are dedicated to understanding the location of food deserts and the benefits of urban gardens. However, few studies have linked these two strands of research together to analyze whether urban gardening activity may be a step forward in addressing issues of access for food desert residents.

METHODS

The Phoenix, Arizona metropolitan area is used as a case to demonstrate the utility of spatial optimization models for siting urban gardens near food deserts and on vacant land. The locations of urban gardens are derived from a list obtained from the Maricopa County Cooperative Extension office at the University of Arizona which were geo located and aggregated to Census tracts. Census tracts were then assigned to one of three categories: tracts that contain a garden, tracts that are immediately adjacent to a tract with a garden, and all other non-garden/non-adjacent census tracts. Analysis of variance is first used to ascertain whether there are statistical differences in the demographic, socio-economic, and land use profiles of these three categories of tracts. A maximal covering spatial optimization model is then used to identify potential locations for future gardening activities. A constraint of these models is that gardens be located on vacant land, which is a growing problem in rapidly urbanizing environments worldwide.

RESULTS

The spatial analysis of garden locations reveals that they are centrally located in tracts with good food access. Thus, the current distribution of gardens does not provide an alternative food source to occupants of food deserts. The maximal covering spatial optimization model reveals that gardens could be sited in alternative locations to better serve food desert residents. In fact, 53 gardens may be located to cover 96.4% of all food deserts. This is an improvement over the current distribution of gardens where 68 active garden sites provide coverage to a scant 8.4% of food desert residents.

CONCLUSION

People in rapidly urbanizing environments around the globe suffer from poor food access. Rapid rates of urbanization also present an unused vacant land problem in cities around the globe. This paper highlights how spatial optimization models can be used to improve healthy food access for food desert residents, which is a critical first step in ameliorating the health problems associated with lack of healthy food access including heart disease and obesity.

Applications of geographic information systems (GIS) data and methods in obesity-related research

Geographic information systems (GIS) data/methods offer good promise for public health programs including obesity-related research. This study systematically examined their applications and identified gaps and limitations in current obesity-related research. A systematic search of PubMed for studies published before 20 May 2016, utilizing synonyms for GIS in combination with synonyms for obesity as search terms, identified 121 studies that met our inclusion criteria. We found primary applications of GIS data/methods in obesity-related research included (i) visualization of spatial distribution of obesity and obesity-related phenomena, and basic obesogenic environmental features, and (ii) construction of advanced obesogenic environmental indicators. We found high spatial heterogeneity in obesity prevalence/risk and obesogenic environmental factors. Also, study design and characteristics varied considerably across studies because of lack of established guidance and protocols in the field, which may also have contributed to the mixed findings about environmental impacts on obesity. Existing findings regarding built environment are more robust than those regarding food environment. Applications of GIS data/methods in obesity research are still limited, and related research faces many challenges. More and better GIS data and more friendly analysis methods are needed to expand future GIS applications in obesity-related research.

Measures of the food environment: A systematic review of the field, 2007-2015

BACKGROUND

Many studies have examined the relationship between the food environment and health-related outcomes, but fewer consider the integrity of measures used to assess the food environment. The present review builds on and makes comparisons with a previous review examining food environment measures and expands the previous review to include a more in depth examination of reliability and validity of measures and study designs employed.

METHODS

We conducted a systematic review of studies measuring the food environment published between 2007 and 2015. We identified these articles through: PubMed, Embase, Web of Science, PsycINFO, and Global Health databases; tables of contents of relevant journals; and the National Cancer Institute's Measures of the Food Environment website. This search yielded 11,928 citations. We retained and abstracted data from 432 studies.

RESULTS

The most common methodology used to study the food environment was geographic analysis (65% of articles) and the domination of this methodology has persisted since the last review. Only 25.9% of studies in this review reported the reliability of measures and 28.2% reported validity, but this was an improvement as compared to the earlier review. Very few of the studies reported construct validity. Studies reporting measures of the school or worksite environment have decreased since the previous review. Only 13.9% of the studies used a longitudinal design.

CONCLUSIONS

To strengthen research examining the relationship between the food environment and population health, there is a need for robust and psychometrically-sound measures and more sophisticated study designs.

Identifying rural food deserts: Methodological considerations for food environment interventions

OBJECTIVES

Food insecurity in an important public health issue and affects 13% of Canadian households. It is associated with poor accessibility to fresh, diverse and affordable food products. However, measurement of the food environment is challenging in rural settings since the proximity of food supply sources is unevenly distributed. The objective of this study was to develop a methodology to identify food deserts in rural environments.

METHODS

In-store evaluations of 25 food products were performed for all food stores located in four contiguous rural counties in Quebec. The quality of food products was estimated using four indices: freshness, affordability, diversity and the relative availability. Road network distance between all residences to the closest food store with a favourable score on the four dimensions was mapped to identify residential clusters located in deprived communities without reasonable access to a "good" food source. The result was compared with the food desert parameters proposed by the US Department of Agriculture (USDA), as well as with the perceptions of a group of regional stakeholders.

RESULTS

When food quality was considered, food deserts appeared more prevalent than when only the USDA definition was used. Objective measurements of the food environment matched stakeholders' perceptions.

CONCLUSION

Food stores' characteristics are different in rural areas and require an in-store estimation to identify potential rural food deserts. The objective measurements of the food environment combined with the field knowledge of stakeholders may help to shape stronger arguments to gain the support of decision-makers to develop relevant interventions.

Retail food environments research in Canada: A scoping review

OBJECTIVES

The field of retail food environments research is relatively new in Canada. The objective of this scoping review is to provide an overview of retail food environments research conducted before July 2015 in Canada. Specifically, this review describes research foci and key findings, identifies knowledge gaps and suggests future directions for research.

METHODS

A search of published literature concerning Canadian investigations of retail food environment settings (food stores, restaurants) was conducted in July 2015 using PubMed, Web of Science, Scopus, PsychInfo and ERIC. Studies published in English that reported qualitative or quantitative data on any aspect of the retail food environment were included, as were conceptual papers and commentaries.

SYNTHESIS

Eighty-eight studies were included in this review and suggest that the field of retail food environments research is rapidly expanding in Canada. While only 1 paper was published before 2005, 66 papers were published between 2010 and 2015. Canadian food environments research typically assessed either the socio-economic patterning of food environments (n = 28) or associations between retail food environments and diet, anthropometric or health outcomes (n = 33). Other papers profiled methodological research, qualitative studies, intervention research and critical commentaries (n = 27). Key gaps in the current literature include measurement inconsistency among studies and a lack of longitudinal and intervention studies.

CONCLUSION

Retail food environments are a growing topic of research, policy and program development in Canada. Consistent methods (where appropriate), longitudinal and intervention research, and close partnerships between researchers and key stakeholders would greatly advance the field of retail food environments research in Canada.

Spatial Supermarket Redlining and Neighborhood Vulnerability: A Case Study of Hartford, Connecticut

The disinclination of chain supermarkets to locate or pull out existing stores from impoverished neighborhoods is termed as "supermarket redlining". This paper attempts to map and understand the spatial effects of potential supermarket redlining on food vulnerability in urban disadvantaged neighborhoods of Hartford, Connecticut. Using a combination of statistical and spatial analysis functions, we first, built a Supermarket Redlining Index (SuRI) from five indicators such as sales volume, employee count, accepts food coupons from federally assisted programs, and size and population density of the service area to rank supermarkets in the order of their importance. Second, to understand the effect of redlining, a Supermarket Redlining Impact Model (SuRIM) was built with eleven indicators describing both the socioeconomic and food access vulnerabilities. The interaction of these vulnerabilities would identify the final outcome: neighborhoods where the impact of supermarket redlining would be critical. Results mapped critical areas in the inner-city of Hartford where if a nearby supermarket closes or relocates to a suburb with limited mitigation efforts to gill the grocery gap, a large number of minority, poor, and disadvantaged residents will experience difficulties to access healthy food leading to food insecurity or perhaps a food desert. We also suggest mitigation efforts to reduce the impact of large supermarket closures.

The geographic distribution of cardiovascular health in the stroke prevention in healthcare delivery environments (SPHERE) study

BACKGROUND

Community-level factors have been clearly linked to health outcomes, but are challenging to incorporate into medical practice. Increasing use of electronic health records (EHRs) makes patient-level data available for researchers in a systematic and accessible way, but these data remain siloed from community-level data relevant to health.

PURPOSE

This study sought to link community and EHR data from an older female patient cohort participating in an ongoing intervention at the Ohio State University Wexner Medical Center to associate community-level data with patient-level cardiovascular health (CVH) as well as to assess the utility of this EHR integration methodology.

MATERIALS AND METHODS

CVH was characterized among patients using available EHR data collected May through July of 2013. EHR data for 153 patients were linked to United States census-tract level data to explore feasibility and insights gained from combining these disparate data sources. Analyses were conducted in 2014.

RESULTS

Using the linked data, weekly per capita expenditure on fruits and vegetables was found to be significantly associated with CVH at the p<0.05 level and three other community-level attributes (median income, average household size, and unemployment rate) were associated with CVH at the p<0.10 level.

CONCLUSIONS

This work paves the way for future integration of community and EHR-based data into patient care as a novel methodology to gain insight into multi-level factors that affect CVH and other health outcomes. Further, our findings demonstrate the specific architectural and functional challenges associated with integrating decision support technologies and geographic information to support tailored and patient-centered decision making therein.

Comparing children's GPS tracks with geospatial proxies for exposure to junk food

Various geospatial techniques have been employed to estimate children's exposure to environmental cardiometabolic risk factors, including junk food. But many studies uncritically rely on exposure proxies which differ greatly from actual exposure. Misrepresentation of exposure by researchers could lead to poor decisions and ineffective policymaking. This study conducts a GIS-based analysis of GPS tracks--'activity spaces'--and 21 proxies for activity spaces (e.g. buffers, container approaches) for a sample of 526 children (ages 9-14) in London, Ontario, Canada. These measures are combined with a validated food environment database (including fast food and convenience stores) to create a series of junk food exposure estimates and quantify the errors resulting from use of different proxy methods. Results indicate that exposure proxies consistently underestimate exposure to junk foods by as much as 68%. This underestimation is important to policy development because children are exposed to more junk food than estimated using typical methods.

Diet-related chronic disease in the northeastern United States: a model-based clustering approach

BACKGROUND

Obesity and diabetes are global public health concerns. Studies indicate a relationship between socioeconomic, demographic and environmental variables and the spatial patterns of diet-related chronic disease. In this paper, we propose a methodology using model-based clustering and variable selection to predict rates of obesity and diabetes. We test this method through an application in the northeastern United States.

METHODS

We use model-based clustering, an unsupervised learning approach, to find latent clusters of similar US counties based on a set of socioeconomic, demographic, and environmental variables chosen through the process of variable selection. We then use Analysis of Variance and Post-hoc Tukey comparisons to examine differences in rates of obesity and diabetes for the clusters from the resulting clustering solution.

RESULTS

We find access to supermarkets, median household income, population density and socioeconomic status to be important in clustering the counties of two northeastern states. The results of the cluster analysis can be used to identify two sets of counties with significantly lower rates of diet-related chronic disease than those observed in the other identified clusters. These relatively healthy clusters are distinguished by the large central and large fringe metropolitan areas contained in their component counties. However, the relationship of socio-demographic factors and diet-related chronic disease is more complicated than previous research would suggest. Additionally, we find evidence of low food access in two clusters of counties adjacent to large central and fringe metropolitan areas. While food access has previously been seen as a problem of inner-city or remote rural areas, this study offers preliminary evidence of declining food access in suburban areas.

CONCLUSIONS

Model-based clustering with variable selection offers a new approach to the analysis of socioeconomic, demographic, and environmental data for diet-related chronic disease prediction. In a test application to two northeastern states, this method allows us to identify two sets of metropolitan counties with significantly lower diet-related chronic disease rates than those observed in most rural and suburban areas. Our method could be applied to larger geographic areas or other countries with comparable data sets, offering a promising method for researchers interested in the global increase in diet-related chronic disease.

Cross-sectional associations between residential environmental exposures and cardiovascular diseases

BACKGROUND

Prior research examining neighbourhood effects on cardiovascular diseases (CVDs) has focused on the impact of neighbourhood socio-economic status or a few selected environmental variables. No studies of cardiovascular disease outcomes have investigated a broad range of urban planning related environmental factors. This is the first study to combine multiple neighbourhood influences in an integrated approach to understanding the association between the built and social environment and CVDs. By modeling multiple neighbourhood level social and environmental variables simultaneously, the study improved the estimation of effects by accounting for potential contextual confounders.

METHODS

Data were collected using a cross-sectional survey (n = 2411) across 87 census tracts (CT) in Toronto, Canada, and commercial and census data were accessed to characterize the residential environment. Multilevel regressions were used to estimate the associations of neighbourhood factors on the risk of CVD.

RESULTS

Exposure to violent crimes, environmental noise, and proximity to a major road were independently associated with increased odds of CVDs (p < 0.05) in the fully adjusted model. While reduced access to food stores, parks/recreation, and increased access to fast food restaurants were associated with increased odds of CVDs in partially adjusted models (p < 0.05), these associations were fully attenuated after adjusting for BMI and physical activity. Housing disrepair was not associated with CVD risk.

CONCLUSIONS

These findings illustrate the importance of measuring and modeling a broad range of neighborhood factors--exposure to violent crimes, environmental noise, and traffic, and access to food stores, fast food, parks/recreation areas--to identify specific stressors in relation to adverse health outcomes. Further research to investigate the temporal order of events is needed to better understand the direction of causation for the observed associations.

What role do local grocery stores play in urban food environments? A case study of Hartford-Connecticut

Introduction

Research on urban food environments emphasizes limited access to healthy food, with fewer large supermarkets and higher food prices. Many residents of Hartford, Connecticut, which is often considered a food desert, buy most of their food from small and medium-sized grocery stores. We examined the food environment in greater Hartford, comparing stores in Hartford to those in the surrounding suburbs, and by store size (small, medium, and large).

Methods

We surveyed all small (over 1,000 ft²), medium, and large-sized supermarkets within a 2-mile radius of Hartford (36 total stores). We measured the distance to stores, availability, price and quality of a market basket of 25 items, and rated each store on internal and external appearance. Geographic Information System (GIS) was used for mapping distance to the stores and variation of food availability, quality, and appearance.

Results

Contrary to common literature, no significant differences were found in food availability and price between Hartford and suburban stores. However, produce quality, internal, and external store appearance were significantly lower in Hartford compared to suburban stores (all p<0.05). Medium-sized stores had significantly lower prices than small or large supermarkets (p<0.05). Large stores had better scores for internal (p<0.05), external, and produce quality (p<0.01). Most Hartford residents live within 0.5 to 1 mile distance to a grocery store.

Discussion

Classifying urban areas with few large supermarkets as ‘food deserts’ may overlook the availability of healthy foods and low prices that exist within small and medium-sized groceries common in inner cities. Improving produce quality and store appearance can potentially impact the food purchasing decisions of low-income residents in Hartford.

A food retail-based intervention on food security and consumption

The effect of the built environment on diet (and ensuing health outcomes) is less understood than the effect of diet on obesity. Natural experiments are increasingly advocated in place of cross-sectional studies unable to suggest causality. The central research question of this paper, therefore, asks whether a neighborhood-level food retail intervention will affect dietary habits or food security. The intervention did not have a significant impact on fruit and vegetable consumption, and the intervention population actually purchased prepared meals more frequently. More problematic, only 8% of respondents overall regularly consumed enough fruits and vegetables, and 34% were food insecure. Further complicating this public health issue, the new grocery store closed after 17 months of operation. Results indicate that geographic access to food is only one element of malnutrition, and that multi-pronged dietary interventions may be more effective. The economic failure of the store also suggests the importance of non-retail interventions to combat malnutrition.

Systems science and childhood obesity: a systematic review and new directions

As a public health problem, childhood obesity operates at multiple levels, ranging from individual health behaviors to school and community characteristics to public policies. Examining obesity, particularly childhood obesity, from any single perspective is likely to fail, and systems science methods offer a possible solution. We systematically reviewed studies that examined the causes and/or consequences of obesity from a systems science perspective. The 21 included studies addressed four general areas of systems science in obesity: (1) translating interventions to a large scale, (2) the effect of obesity on other health or economic outcomes, (3) the effect of geography on obesity, and (4) the effect of social networks on obesity. In general, little research addresses obesity from a true, integrated systems science perspective, and the available research infrequently focuses on children. This shortcoming limits the ability of that research to inform public policy. However, we believe that the largely incremental approaches used in current systems science lay a foundation for future work and present a model demonstrating the system of childhood obesity. Systems science perspective and related methods are particularly promising in understanding the link between childhood obesity and adult outcomes. Systems models emphasize the evolution of agents and their interactions; such evolution is particularly salient in the context of a developing child.

Effect of bednets and indoor residual spraying on spatio-temporal clustering of malaria in a village in south Ethiopia: a longitudinal study

BACKGROUND

Understanding the spatio-temporal pattern of malaria transmission where prevention and control measures are in place will help to fine-tune strategies. The objective of this study was to assess the effect of mass distribution of bednets and indoor residual spraying (IRS) with insecticides on the spatio-temporal clustering of malaria in one malaria endemic village in south Ethiopia.

METHODS

A longitudinal study was conducted from April 2009 to April 2011. The average population was 6631 in 1346 locations. We used active and passive searches for malaria cases for 101 weeks. SatScan v9.1.1 was used to identify statistically significant retrospective space-time clusters. A discrete Poisson based model was applied with the aim of identifying areas with high rates. PASW Statistics 18 was used to build generalized Poisson loglinear model.

RESULTS

The total number of both types of malaria episodes was 622, giving 45.1 episodes per 1000 persons per year; among these, episodes of Plasmodium falciparum and vivax infection numbered 316 (22.9 per 1000 per year) and 306 (22.2 per 1000 per year), respectively. IRS with Dichlorodiphenyltrichloroethane (DDT) and later with Deltamethrin and free mass distribution of insecticide-treated nets (ITNs) were carried out during the study period. There was space-time clustering of malaria episodes at a household level. The spatio-temporal clustering of malaria was not influenced by free mass distribution of ITNs; however, the time-span of the spatio-temporal clustering of malaria cases ended after IRS with Deltamethrin. The presence of clusters on the south-east edge of the village was consistent with the finding of an increasing risk of acquiring malaria infection for individuals who lived closer to the identified vector breeding site.

CONCLUSION

The risk of getting malaria infection varied significantly within one village. Free mass distribution of ITNs did not influence the spatio-temporal clustering of malaria, but IRS might have eliminated malaria clustering.

Quantifying the magnitude of environmental exposure misclassification when using imprecise address proxies in public health research

In spatial epidemiologic and public health research it is common to use spatially aggregated units such as centroids of postal/zip codes, census tracts, dissemination areas, blocks or block groups as proxies for sample unit locations. Few studies, however, address the potential problems associated with using these units as address proxies. The purpose of this study is to quantify the magnitude of distance errors and accessibility misclassification that result from using several commonly-used address proxies in public health research. The impact of these positional discrepancies for spatial epidemiology is illustrated by examining misclassification of accessibility to several health-related facilities, including hospitals, public recreation spaces, schools, grocery stores, and junk food retailers throughout the City of London and Middlesex County, Ontario, Canada. Positional errors are quantified by multiple neighborhood types, revealing that address proxies are most problematic when used to represent residential locations in small towns and rural areas compared to suburban and urban areas. Findings indicate that the shorter the threshold distance used to measure accessibility between subject population and health-related facility, the greater the proportion of misclassified addresses. Using address proxies based on large aggregated units such as centroids of census tracts or dissemination areas can result in very large positional discrepancies (median errors up to 343 and 2088 m in urban and rural areas, respectively), and therefore should be avoided in spatial epidemiologic research. Even smaller, commonly-used, proxies for residential address such as postal code centroids can have large positional discrepancies (median errors up to 109 and 1363 m in urban and rural areas, respectively), and are prone to misrepresenting accessibility in small towns and rural Canada; therefore, postal codes should only be used with caution in spatial epidemiologic research.