Conceptualization and measurement of environmental exposure in epidemiology: Accounting for activity space related to daily mobility

A brief review of methods for determining time-activity patterns in California

Air pollution exposure has been found to be linked with numerous adverse human health effects. Because both air pollution concentrations and the location of human individuals change spatiotemporally, understanding the time-activity patterns (TAPs) is of utmost importance for the mitigation of adverse exposures and to improve the accuracy of air pollution and health analyses. "Time-activity patterns" outlined here broadly refer to the spatiotemporal positions of individuals. In this review paper, we briefly review past efforts on collecting individual TAP information for air pollution and health studies, with a specific focus on California efforts. We also critically summarize emerging technologies and approaches for collecting TAP data. Specifically, we critically reviewed five types of emerging TAP data sources, including call detail record, social media location data, Google Location History, iPhone Significant Location, and crowd-sourced location data. This review provides a comprehensive summary and critique of different methods to collect TAP information and offers recommendations for use in retrospective air pollution and health studies.Implications: In this review paper, we provide a comprehensive overview of approaches for collecting time-activity pattern (TAP) data from individuals, a crucial component in understanding human behavior and its implications across various fields such as urban planning, environmental science, and, particularly, public health in relation to air pollution exposures.Furthermore, our paper introduces and critically evaluates several emerging methods for TAP data collection. These novel approaches, including but not limited to Google Location History, iPhone Significant Locations, and crowdsourced smartphone location data, offer unprecedented granularity in tracking human activities. By showcasing these methodologies and their often not well-recognized weaknesses, we highlight both the potential and limitations of these tools to advance our understanding of human behavior patterns, especially in terms of how individuals interact with their environments. This discussion not only showcases the originality of our work but also sets the stage for future research directions that can benefit from these innovative data collection strategies.

Activity Space Mapping and Pre-Exposure Prophylaxis Uptake Among Gay, Bisexual, and Other Sexual Minority Men in Small Cities and Towns in the United States

In the US, gay, bisexual, and other sexual minoritized men (GBSMM) remain disproportionately impacted by HIV, and continue to experience unmet needs for pre-exposure prophylaxis (PrEP). A growing body of literature has underscored the need to consider the geographic factors of HIV prevention, particularly beyond administrative boundaries and towards localized spaces that influence the accessibility and utilization of health-promoting resources. Therefore, the purpose of this study is to examine the associations of driving times from activity spaces to PrEP offering facilities and individual PrEP uptake. A total of 218 GBSMM (ages 18-34) from Connecticut and Georgia were sampled from a longitudinal cohort study. We used the getis-ord-gi statistic to examine the spatial clustering of PrEP offering facilities, and generalized estimating equations (GEE) and post-hoc moderation analyses to explore the state interactions on driving time and PrEP uptake. Our main findings suggest that for participants in Connecticut, state of residence was a significant moderator on driving time and ever hearing of PrEP and ever taking PrEP. Whereas for participants in Georgia, state of residence moderated the likelihood of returning to activity spaces of participants in both Connecticut and Georgia on PrEP uptake. These findings provide important direction for geographic inequities on PrEP use, but also a pragmatic method for co-creating and re-imagining place-health research. These results also offer an avenue to leverage the dynamic nuance of activity spaces as indicators to inform structural interventions for PrEP that are more equitable for GBSMM in small cities and towns in the U.S.

Social inequalities in green exposure in small- and medium-sized U.S. cities: A mobility-based approach

BACKGROUND

Green space exposure has been considered essential for people's physical and mental health. Researchers have investigated uneven exposure to green space based on individuals' home locations, which may exacerbate health disparities. A mobility-based approach enables a more accurate assessment of green exposure in daily activity patterns. In addition, social inequalities may vary by geographical context and should be examined to address environmental justice concerns.

OBJECTIVE

Study objectives are twofold: to address methodological challenges in exposure assessment studies through mobility-based assessment of green exposure; and to explore whether mobility-based approach can better assess green exposure inequality than home-based measurement.

METHODS

We selected 25 small- and medium-sized U.S. cities as study sites, from which street-view images were collected along 50,823 walk-based commute trajectories. We applied a semantic segmentation technique to street-view images to estimate individual home- and mobility-based green exposure levels.

RESULTS

Results revealed that mobility-based green exposure significantly differs from home-based green exposure. Globally, wealthier individuals and non-minority groups experience significantly greater exposure to green space through both home- and mobility-based approaches compared to their counterparts. Locally, we found more nuanced pictures of green space inequalities when compared at the county level, suggesting locally varying relationships.

SIGNIFICANCE

This study suggests empirical evidence on how mobility-based measurements could help us assess inequality problems in exposure to urban green elements.

IMPACT

Creating urban green corridors that comply with locally varying contexts can contribute to achieving equitable provision of green infrastructure for low-income and racially disadvantaged populations who have undesirable green exposure in their residential locations.

Interplay between genetic risk and built neighborhood conditions as predictor of BMI across the transition into adulthood

OBJECTIVE

We examined BMI development across changes in the built environment during the transition from adolescence to young adulthood and explored the moderating role of genetic risk.

METHODS

We used longitudinal data from individuals aged 16 to 25 years in the TRacking Adolescents' Individual Lives Survey (TRAILS) that we linked to built environment data for 2006, 2010, and 2016 from the Geoscience and Health Cohort Consortium (GECCO). We fitted a latent growth model of BMI and examined associations of changes in fast-food restaurant density and walkability with changes in BMI (n = 2735), as well as interactions of changes in fast-food restaurant density and walkability with genetic risk (n = 1676).

RESULTS

Changes in fast-food restaurant density (e.g., Δ2010-2006: β = -0.04, 95% CI: -0.11 to 0.03) and walkability (e.g., Δ2010-2006: β = -0.05, 95% CI: -0.14 to 0.05) were not associated with BMI changes. Additionally, genetic risk did not moderate these associations.

CONCLUSIONS

We found limited evidence that moving to neighborhoods with higher fast-food restaurant density or less walkability was associated with BMI changes or that genetic risk moderated these associations. Our findings suggest that associations between the built environment and BMI changes during the transition into young adulthood are likely small.

A comprehensive GPS-based analysis of activity spaces in early and late pregnancy using the ActMAP framework

Health implications of mobility during pregnancy entail a need to understand pregnant women's activity spaces. We present ActMAP, a framework for quantifying multiple aspects of activity spaces from distinct trips and stays derived from GPS data. We applied ActMAP to data from 238 pregnant women in Barcelona, Spain (2018-2020) and explored weekday, weekend and intraday associations between pregnancy trimester and activity spaces. Activities were more centred around the home later in pregnancy. However, the number of visited places and daily trips remained largely constant throughout pregnancy. By constructing activity spaces from individual trips and stays, ActMAP could provide a framework for GPS-based holistic assessments of mobility.

Measuring associations between the food environment and dietary habits: comparing the proportion and density of food outlets

BACKGROUND

The food environment plays a crucial role in shaping our dietary choices and overall health. Spatial measures provide distinct perspectives on the physical food environment and its impact on diet. While proportion measures are theoretically considered to provide a more accurate representation of the overall physical food environment than density measures, it is important to recognize that the association between food environments and diet can vary depending on the context. Therefore, relying solely on one measure may not be appropriate.

METHODS

We systematically assessed the density and proportion of multiple food outlet types (fast-food outlets, convenience stores, supermarkets, and restaurants) around individuals homes using a large cross-sectional Danish study (N = 71,840). Densities were modeled in separate multilevel linear regression models, incorporating random intercepts from linear splines for each of the four food outlet types. Proportions were modeled without splines. Through the association with a dietary quality score (DQS), we examined the impact of quantifying the foodscape from density versus proportion measures. Associations were compared using parameter estimates, p-values, Akaike Information Criterion (AIC) values, and Akaike weights.

RESULTS

AIC values and Akaike weights were in favor of models including density measures. Across all outlet types, density measures were consistently negatively associated with the DQS until reaching densities of 3-5 (count/km2), at which point the direction of association became positive, indicating a shift towards a healthier DQS. After correcting for multiple comparisons, the most significant effect was observed for the sole significant proportion measure. A 10% increase in the proportion of fast-food outlets among "eating out options" was associated with a 7% decrease in the DQS, towards poorer dietary quality.

CONCLUSIONS

The associations highlight that choosing food outlet density versus proportions to quantify the foodscape impact findings of substantial importance when considering the significance level and direction of association. Findings suggests a threshold effect when using density measures indicating abundance of many food outlets, at which the association with dietary quality alters significantly towards healthier diet quality.

Relationship of Community Mobility, Vital Space, and Faller Status in Older Adults

Community mobility, encompassing both active (e.g., walking) and passive (e.g., driving) transport, plays a crucial role in maintaining autonomy and social interaction among older adults. This study aimed to quantify community mobility in older adults and explore the relationship between GPS- and accelerometer-derived metrics and fall risk.

METHODS

A total of 129 older adults, with and without a history of falls, were monitored over an 8 h period using GPS and accelerometer data. Three experimental conditions were evaluated: GPS data alone, accelerometer data alone, and a combination of both. Classification models, including Random Forest (RF), Support Vector Machines (SVMs), and K-Nearest Neighbors (KNN), were employed to classify participants based on their fall history.

RESULTS

For GPS data alone, RF achieved 74% accuracy, while SVM and KNN reached 67% and 62%, respectively. Using accelerometer data, RF achieved 95% accuracy, and both SVM and KNN achieved 90%. Combining GPS and accelerometer data improved model performance, with RF reaching 97% accuracy, SVM achieving 95%, and KNN 87%.

CONCLUSION

The integration of GPS and accelerometer data significantly enhances the accuracy of distinguishing older adults with and without a history of falls. These findings highlight the potential of sensor-based approaches for accurate fall risk assessment in community-dwelling older adults.

Using confirmatory principal component analysis to uncover the interplay between social and spatial factors among older adults: An exploratory study

This study examines the complex interplay between social and spatial structures among older adults, emphasizing the interest in considering the social composition of activity spaces and the spatial characteristics of social networks. There is a growing interest in the collection and analysis of both social and daily mobility spatial information to better understand people-place interactions and determinants of health. Yet, few analyses have explored how the social and spatial dimensions of people's lives relate. In this exploratory study, we analyze how social and spatial indicators collected with the VERITAS-Social questionnaire among 98 older adults in Montréal, Canada, relate, using confirmatory principal component analysis. The aim of the article is to provide empirical evidence on the reduction of dimensions of measures related to social networks, activity spaces, and combined socio-spatial structures.

Objective Neighborhood-Level Disorder Versus Subjective Safety as Predictors of HIV Transmission Risk and Momentary Well-Being

Mental health and HIV risk behavior have been studied with ecological momentary assessment (EMA), but this approach has not been combined with tracking of activity space (where people go and what they encounter there) in people with HIV and their social relations, who may be HIV+ or HIV-. Activity space represents a modifiable risk or protective factor for behavior related to health status and quality of life, in both clinical and nonclinical populations. We conducted an observational study with 286 participants (243 HIV+ and 43 HIV-), roughly matched for socioeconomic status and neighborhood of residence via three waves of snowball sampling. Each participant carried a smartphone for up to 4 weeks, making 5 randomly prompted entries and 1 end-of-day entry each day, plus self-initiated event-contingent entries for sexual activity and drug use. Responses to randomly prompted items provided subjective evaluations of the safety of the participant's current social and physical environment (the place they were and the people they were with). GPS-based location tracking-coupled with publicly available statistic indicating neighborhood-level physical disorder and socioeconomic disadvantage-provided an indicator of each participant's exposure to objective psychosocial hazard. We examined possible relationships of these objective and subjective environmental exposures with risky sexual and intravenous drug-use behavior, knowledge and utilization of antiretroviral treatment and prophylaxis, and momentary mental health (mood and stress, which relate to risky behavior and overall well-being). We found that both risky behavior and mental health were more related to participants' subjective evaluations of their activity space than to objective measures of neighborhood-level disorder, suggesting that, even within an objectively hazardous neighborhood, people who find a niche they perceive as socially and physically safe may engage in less risky behavior and have better well-being.Trial registration Clinicaltrials.gov Identifier NCT01571752.

Is home where the heat is? comparing residence-based with mobility-based measures of heat exposure in San Diego, California

BACKGROUND

Heat can vary spatially within an urban area. Individual-level heat exposure may thus depend on an individual's day-to-day travel patterns (also called mobility patterns or activity space), yet heat exposure is commonly measured based on place of residence.

OBJECTIVE

In this study, we compared measures assessing exposure to two heat indicators using place of residence with those defined considering participants' day-to-day mobility patterns.

METHODS

Participants (n = 599; aged 35-80 years old [mean =59 years]) from San Diego County, California wore a GPS device to measure their day-to-day travel over 14-day intervals between 2014-10-17 and 2017-10-06. We measured exposure to two heat indicators (land-surface temperature [LST] and air temperature) using an approach considering their mobility patterns and an approach considering only their place of residence. We compared participant mean and maximum exposure values from each method for each indicator.

RESULTS

The overall mobility-based mean LST exposure (34.7 °C) was almost equivalent to the corresponding residence-based mean (34.8 °C; mean difference in means = -0.09 °C). Similarly, the mean difference between the overall mobility-based mean air temperature exposure (19.2 °C) and the corresponding residence-based mean (19.2 °C) was negligible (-0.02 °C). Meaningful differences emerged, however, when comparing maximums, particularly for LST. The mean mobility-based maximum LST was 40.3 °C compared with a mean residence-based maximum of 35.8 °C, a difference of 4.51 °C. The difference in maximums was considerably smaller for air temperature (mean = 0.40 °C; SD = 1.41 °C) but nevertheless greater than the corresponding difference in means.

IMPACT

As the climate warms, assessment of heat exposure both at and away from home is important for understanding its health impacts. We compared two approaches to estimate exposure to two heat measures (land surface temperature and air temperature). The first approach only considered exposure at home, and the second considered day-to-day travel. Considering the average exposure estimated by each approach, the results were almost identical. Considering the maximum exposure experienced (specific definition in text), the differences between the two approaches were more considerable, especially for land surface temperature.

Racial, ethnic, and neighborhood socioeconomic disparities in local cannabis retail policy in California

BACKGROUND

Policies governing legal cannabis commerce can vary widely within a U.S. state when local control exists. Disproportionate distribution of policies allowing retail sale, protecting public health, or promoting equity in licensing may contribute to differences in health and economic outcomes between sociodemographic subgroups. This cross-sectional study jointly examined racial, ethnic, and neighborhood socioeconomic characteristics of Californians subject to specific local cannabis policies to identify such disparities.

METHODS

Local laws in effect January 1, 2020, governing retail cannabis sales (bans, expanding buffers from youth-serving sites, restricting advertising, promoting equity in licensing, and capping outlets) were determined for California's 539 jurisdictions. The number of Asian, Black, Latinx, and white residents in socioeconomic advantaged versus disadvantaged neighborhoods (Census block groups) was determined using 2015-2019 American Community Survey data. We estimated proportions of the sociodemographic subpopulations covered by specific policies based on the block group's jurisdiction. To ascertain disparities in coverage proportions were compared across subgroups using Z-tests with the Bonferroni correction.

RESULTS

Residents of socioeconomically advantaged neighborhoods were more likely to live in jurisdictions allowing retail cannabis commerce than those in disadvantaged neighborhoods (61.7 % versus 54.8 %). Black residents in advantaged neighborhoods were most likely to live where retailing was allowed (69 %), and white residents in disadvantaged neighborhoods least likely (49 %). Latinx and Black populations from disadvantaged neighborhoods were most likely to live in jurisdictions with stronger advertising restrictions (66 %). Equity in licensing policy was more prevalent for Black residents living in advantaged neighborhoods (57 %) than disadvantaged neighborhoods (49 %).

CONCLUSIONS

Local cannabis policies potentially protecting public health and social equity are unequally distributed across race, ethnicity, and socioeconomic characteristics in California. Research examining whether differential policy exposure reduces, creates, or perpetuates cannabis-related health and socioeconomic disparities is needed.

Local retail food environment exposure and diet quality in rural and urban adults: A longitudinal analysis of the ORISCAV-LUX cohort study

Despite growing interest in understanding how food environments shape dietary behaviors, European longitudinal evidence is scarce. We aimed to investigate the associations of 9-year average and change in exposure to local retail food environments with the diet quality of residents in Luxembourg. We used data from 566 adults enrolled in both waves of the nationwide ORISCAV-LUX study (2007-2017). Dietary quality was assessed by the Diet Quality Index-International (DQI-I). Exposure to "healthy" and "less healthy" food outlets was assessed by both absolute and relative GIS-based measurements. The results showed a 56.3% increase in less healthy food outlets over the period. In adjusted linear mixed models, high (vs. low) 9-year average exposure to less healthy food outlets was associated with lower DQI-I, when examining spatial access (β = -1.25, 95% CI: -2.29, -0.22) and proportions (β = -1.24, 95% CI: -2.15, -0.33). Stratified analyses showed these associations to be significant only among urban residents. There was no association between change in exposure to less healthy food outlets and DQI-I. Increased exposure to healthy outlets in rural areas, using absolute measurements, was associated with worsened DQI-I. Neighborhood socioeconomic status did not moderate the above associations. Findings suggest that the proliferation of less healthy food outlets may have contributed to the deterioration of the diet quality of urban residents, and support the use of relative measurements to fully capture the healthiness of food environments.

Urban environment and health: a cross-sectional multiregional project based on population health surveys in Spain (DAS-EP project) - study protocol

INTRODUCTION

The European Environment Agency estimates that 75% of the European population lives in cities. Despite the many advantages of city life, the risks and challenges to health arising from urbanisation need to be addressed in order to tackle the growing burden of disease and health inequalities in cities. This study, Urban environment and health: a cross-sectional multiregional project based on population health surveys in Spain (DAS-EP project), aims to investigate the complex association between the urban environmental exposures (UrbEEs) and health.

METHODS AND ANALYSIS

DAS-EP is a Spanish multiregional cross-sectional project that combines population health surveys (PHS) and geographical information systems (GIS) allowing to collect rich individual-level data from 17 000 adult citizens participating in the PHS conducted in the autonomous regions of the Basque Country, Andalusia, and the Valencian Community, and the city of Barcelona in the years 2021-2023. This study focuses on the population living in cities or metropolitan areas with more than 100 000 inhabitants. UrbEEs are described by objective estimates at participants' home addresses by GIS, and subjective indicators present in PHS. The health outcomes included in the PHS and selected for this study are self-perceived health (general and mental), prevalence of chronic mental disorders, health-related quality of life, consumption of medication for common mental disorders and sleep quality. We aim to further understand the direct and indirect effects between UrbEEs and health, as well as to estimate the impact at the population level, taking respondents' sociodemographic and socioeconomic characteristics, and lifestyle into consideration.

ETHICS AND DISSEMINATION

The study was approved by the regional Research Ethics Committee of the Basque Country (Ethics Committee for Research Involving Medicinal Products in the Basque Country; PI2022138), Andalusia (Biomedical Research Ethics Committee of the Province of Granada; 2078-N-22), Barcelona (CEIC-PSMar; 2022/10667) and the Valencian Community (Ethics Committee for Clinical Research of the Directorate General of Public Health and Center for Advanced Research in Public Health; 20221125/04). The results will be communicated to the general population, health professionals, and institutions through conferences, reports and scientific articles.

Global positioning system-based food environment exposures, diet-related, and cardiometabolic health outcomes: a systematic review and research agenda

BACKGROUND

Geographic access to food may affect dietary choices and health outcomes, but the strength and direction of associations may depend on the operationalization of exposure measures. We aimed to systematically review the literature on up-to-date evidence on the association between food environment exposures based on Global Positioning System (GPS) and diet-related and cardiometabolic health outcomes.

METHODS

The databases PubMed, Embase.com, APA PsycInfo (via Ebsco), Cinahl (via Ebsco), the Web of Science Core Collection, Scopus, and the International Bibliography of the Social Sciences (via ProQuest) were searched from inception to October 31, 2022. We included studies that measured the activity space through GPS tracking data to identify exposure to food outlets and assessed associations with either diet-related or cardiometabolic health outcomes. Quality assessment was evaluated using the criteria from a modified version of the Newcastle-Ottawa Scale (NOS) for cross-sectional studies. We additionally used four items from a quality assessment tool to specifically assess the quality of GPS measurements.

RESULTS

Of 2949 studies retrieved, 14 studies fulfilled our inclusion criteria. They were heterogeneous and represent inconsistent evidence. Yet, three studies found associations between food outlets and food purchases, for example, more exposure to junk food outlets was associated with higher odds of junk food purchases. Two studies found associations between greater exposure to fast food outlets and higher fast food consumption and out of three studies that investigated food environment in relation to metabolic outcomes, two studies found that higher exposure to an unhealthy food environment was associated with higher odds of being overweight.

CONCLUSIONS

The current and limited evidence base does not provide strong evidence for consistent associations of GPS-based exposures of the food environment with diet-related and cardiometabolic health outcomes.

Activity space during treatment with medication for opioid use disorder: Relationships with personality, mood, and drug use

INTRODUCTION

Activity space in people with substance use disorders (SUDs) has been assessed for theoretical reasons and for detection/prevention of relapse. In this observational study, we relate passively obtained activity space measures to mental states and behaviors relevant to the success of treatment for opioid use disorder. Our long-term goal is to use such data to assess risk in real time and to recognize when SUD patients might benefit from a just-in-time intervention.

METHODS

We used GPS data from 238 urban residents in the first 16 weeks of stabilization on medication for opioid use disorder to test preregistered hypotheses about activity space (distance traveled, number of locations, time spent moving, and psychosocial-hazard levels of neighborhoods where participants spent time) in relation to certain static variables (personality, mood propensities) and time-varying treatment-relevant behaviors such as craving and use of opioids and cocaine.

RESULTS

The most consistent findings were that 1) mobility decreased over the course of the study; 2) neuroticism was associated with overall lower mobility; 3) trait-like positive mood (averaged from momentary ratings) was associated with higher mobility; 4) participants who used cocaine more frequently had lower mobility; 5) early in treatment, participants spent less time moving (i.e., were more sedentary) on days when they were craving. Some of these findings were in the expected direction (i.e., the ones involving neuroticism and positive mood), and some were opposite to the expected direction (i.e., we expected cocaine use to be associated with higher mobility); others (e.g., changes in mobility over time or in relation to craving) involved nondirectional hypotheses.

CONCLUSIONS

Real-time information that patients actively provide is valuable for assessing their current state, but providing this information can be burdensome. The current results indicate that certain static or passively obtained data (personality variables and GPS-derived mobility information) are relevant to time-varying, treatment-relevant mental states and drug-related behavior, and therefore might be useful when incorporated into algorithms for detecting need for intervention in real time. Further research should assess how population-specific these relationships are, and how these passive measures can best be combined with low temporal-density, actively-provided data to obtain valid, reliable assessments with minimal burden.

Measuring environmental exposures in people's activity space: The need to account for travel modes and exposure decay

BACKGROUND

Accurately quantifying people's out-of-home environmental exposure is important for identifying disease risk factors. Several activity space-based exposure assessments exist, possibly leading to different exposure estimates, and have neither considered individual travel modes nor exposure-related distance decay effects.

OBJECTIVE

We aimed (1) to develop an activity space-based exposure assessment approach that included travel modes and exposure-related distance decay effects and (2) to compare the size of such spaces and the exposure estimates derived from them across typically used activity space operationalizations.

METHODS

We used 7-day-long global positioning system (GPS)-enabled smartphone-based tracking data of 269 Dutch adults. People's GPS trajectory points were classified into passive and active travel modes. Exposure-related distance decay effects were modeled through linear, exponential, and Gaussian decay functions. We performed cross-comparisons on these three functional decay models and an unweighted model in conjunction with four activity space models (i.e., home-based buffers, minimum convex polygons, two standard deviational ellipses, and time-weighted GPS-based buffers). We applied non-parametric Kruskal-Wallis tests, pair-wise Wilcoxon signed-rank tests, and Spearman correlations to assess mean differences in the extent of the activity spaces and correlations across exposures to particulate matter (PM2.5), noise, green space, and blue space.

RESULTS

Participants spent, on average, 42% of their daily life out-of-home. We observed that including travel modes into activity space delineation resulted in significantly more compact activity spaces. Exposure estimates for PM2.5 and blue space were significantly (p < 0.05) different between exposure estimates that did or did not account for travel modes, unlike noise and green space, for which differences did not reach significance. While the inclusion of distance decay effects significantly affected noise and green space exposure assessments, the decay functions applied appear not to have had any impact on the results. We found that residential exposure estimates appear appropriate for use as proxy values for the overall amount of PM2.5 exposure in people's daily lives, while GPS-based assessments are suitable for noise, green space, and blue space.

SIGNIFICANCE

For some exposures, the tested activity space definitions, although significantly correlated, exhibited differing exposure estimate results based on inclusion or exclusion of travel modes or distance decay effect. Results only supported using home-based buffer values as proxies for individuals' daily short-term PM2.5 exposure.

Neighborhood-level Residential Isolation and Neighborhood Composition: Similar but Different

Residential segregation has been considered as a potential cause of racial and/or ethnic disparities in health. Among the five dimensions of residential segregation, the isolation dimension has been conceived to play an essential role in disproportionately shaping the health of racial and ethnic minorities, particularly in urban or metropolitan areas. However, a noticeable amount of research studies has been using informal measures of neighborhood composition (i.e., proportions or percentages), which do not capture any of the five dimensions of residential segregation. Since the inappropriateness of measurement may obstruct a meaningful interpretation and an effective dissemination of research findings, a combination of graphical and non-graphical techniques was used to demonstrate the similarities and differences between formal measures of neighborhood-level residential isolation and informal measures of neighborhood composition. These were intended to provide intuitive and mutual understandings across academic disciples (e.g., city or urban planning, geography, public health, and sociology) and practitioners or professionals in multiple fields (e.g., community development workers, health service providers, policymakers, and social workers). Conceptual and methodological explanations with analytical discussions are also provided to differentiate and/or distinguish the two types of measures. While the concepts, methodologies, and research implications discussed herein are most relevant for research studies in urban or metropolitan areas of the United States, the general framework is also applicable to those of other industrialized counties.

Does the built environment influence location- and trip-based sedentary behaviors? Evidence from a GPS-based activity space approach of neighborhood effects on older adults

OBJECTIVE

Evidence on the influence of built environments on sedentary behaviors remains unclear and is often contradictory. The main limitations encompass the use of self-reported proxies of sedentary time (ST), the scarce consideration of the plurality of sedentary behaviors, and environmental exposures limited to the residential neighborhood. We investigated the relationships between GPS-based activity space measures of environmental exposures and accelerometer-based ST measured in total, at the place of residence, at all locations, and during trips.

METHODS

This study is part of the CURHA project, based on 471 older adults residing in Luxembourg, who wore a GPS receiver and a tri-axial accelerometer during 7 days. Daily ST was computed in total, at the residence, at all locations and during trips. Environmental exposures included exposure to green spaces, walking, biking, and motorized transportation infrastructures. Associations between environments and ST were examined using linear and negative binomial mixed models, adjusted for demographics, self-rated health, residential self-selection, weather conditions and wear time.

RESULTS

Participants accumulated, on average, 8 h and 14 min of ST per day excluding sleep time. ST spent at locations accounted for 83 % of the total ST. ST spent at the residence accounted for 87 % of the location-based ST and 71 % of the total ST. Trip-based ST represents 13 % of total ST, and 4 % remained unclassified. Higher street connectivity was negatively associated with total ST, while the density of parking areas correlated positively with total and location-based ST. Stronger associations were observed for sedentary bouts (uninterrupted ST over 20 and 30 min).

CONCLUSION

Improving street connectivity and controlling the construction of new parking, while avoiding the spatial segregation of populations with limited access to public transport, may contribute to limit ST. Such urban planning interventions may be especially efficient in limiting the harmful uninterrupted bouts of ST among older adults.

Subjective and objective indicators of neighbourhood safety and physical activity among UK adolescents

BACKGROUND

The health benefits of regular physical activity in adolescence are well-documented and many health-related behaviours are established in adolescence. The neighbourhood environment is a key setting for physical activity for adolescents and feeling unsafe in their neighbourhood may be a potential barrier to physical activity.

AIM

This study aimed to examine associations between neighbourhood safety and physical activity using objective and subjective measures for both.

METHODS

Participants (n = 10,913) came from the Millennium Cohort Study, a nationally representative UK longitudinal birth cohort. Linear regression and Zero Inflated Poisson models were used to examine associations between subjective and objective indicators of safety (self-reported safety, Index of Multiple Deprivation crime, Reported Crime Incidence) and physical activity (self-reported weekly and device-measured physical activity).

RESULTS

Adolescents who feel unsafe in their neighbourhood, or who live in areas with high IMD crime or violent crime rates report 0.29 (95% CI -0.49, -0.09) 0.32 (95% CI -0.47, -0.16) and 0.20 (95% CI -0.39, -0.20) fewer days of physical activity, respectively. No associations were found between Reported Crime Incidence and either objective or subjective measures of physical activity.

CONCLUSIONS

This study demonstrates varying associations between subjective safety and objective crime with physical activity levels in adolescence, highlighting the complexities around subjective and objective measurements and their associations with health outcomes.

A detour for snacks and beverages? A cross-sectional assessment of selective daily mobility bias in food outlet exposure along the commuting route and dietary intakes

The evidence of selective daily mobility bias distorting exposure-health associations is limited. Using 7-day smartphone-based global positioning system (GPS) tracking data for 67 Dutch adults aged 25-45, we conducted paired Wilcoxon tests to compare the absolute and relative exposure to food outlets along actual and modelled commuting routes. We fitted Tobit regressions to examine their associations with three daily snack and soft drink intake outcomes. We found significant differences in absolute food outlet exposure between two types of routes. Adjusted regression analyses yielded unexpected associations between dietary intakes and food outlet exposures. Our results suggested no evidence of a selective daily mobility bias in the association between the food environment along commuting routes and adults' snacks and soft drink consumption in this sample.

Impact of native-plants policy scenarios on premature mortality in Denver: A quantitative health impact assessment

BACKGROUND

Cities often use non-native plants such as turf grass to expand green space. Native plants, however, may require less water and maintenance and have co-benefits for local biodiversity, including pollinators. Previous studies estimating mortality averted by adding green space have not considered the provision of native plants as part of the greening policies.

AIM

We aim to estimate premature deaths that would be prevented by the implementation of native-plants policy scenarios in the City of Denver, Colorado, USA.

METHODS

After conducting interviews with local expert stakeholders, we designed four native-plants policy scenarios: (1) greening 30% of all city census-block groups to the greenness level of native plants, (2) adding 200-foot native-plants buffers around riparian areas, (3) constructing large water retention ponds landscaped with native plants, and (4) greening parking lots. We defined the normalized difference vegetation index (NDVI) corresponding to native plants by measuring the NDVI at locations with known native or highly diverse vegetation. Using a quantitative health-impact assessment approach, we estimated premature mortality averted under each scenario, comparing alternative NDVI with the baseline value.

RESULTS

In the most ambitious scenario, we estimated that 88 (95% uncertainty interval (UI): 20, 128) annual premature deaths would be prevented by greening 30% of the area of census block groups with native plants. We estimated that greening 30% of parking-lot surface with native plants would prevent 14 annual deaths (95% UI: 7, 18), adding the native buffers around riparian areas would prevent 13 annual deaths (95% UI: 2, 20), and adding the proposed stormwater retention ponds would prevent no annual deaths (95% UI: 0, 1).

CONCLUSION

Using native plants to increase green spaces has the potential to prevent premature deaths in the City of Denver, but results were sensitive to the definition of native plants and the policy scenario.

Novel Location-Based Survey Using Cognitive Interviews to Assess Geographic Networks and Hotspots of Sex and Drug Use: Implementation and Validation Study

BACKGROUND

The Ending the HIV Epidemic initiative in the United States relies on HIV hotspots to identify where to geographically target new resources, expertise, and technology. However, interventions targeted at places with high HIV transmission and infection risk, not just places with high HIV incidence, may be more effective at reducing HIV incidence and achieving health equity.

OBJECTIVE

We described the implementation and validation of a web-based activity space survey on HIV risk behaviors. The survey was intended to collect geographic information that will be used to map risk behavior hotspots as well as the geography of sexual networks in Los Angeles County.

METHODS

The survey design team developed a series of geospatial questions that follow a 3-level structure that becomes more geographically precise as participants move through the levels. The survey was validated through 9 cognitive interviews and iteratively updated based on participant feedback until the saturation of topics and technical issues was reached.

RESULTS

In total, 4 themes were identified through the cognitive interviews: functionality of geospatial questions, representation and accessibility, privacy, and length and understanding of the survey. The ease of use for the geospatial questions was critical as many participants were not familiar with mapping software. The inclusion of well-known places, landmarks, and road networks was critical for ease of use. The addition of a Google Maps interface, which was familiar to many participants, aided in collecting accurate and precise location information. The geospatial questions increased the length of the survey and warranted the inclusion of features to simplify it and speed it up. Using nicknames to refer to previously entered geographic locations limited the number of geospatial questions that appeared in the survey and reduced the time taken to complete it. The long-standing relationship between participants and the research team improved comfort to disclose sensitive geographic information related to drug use and sex. Participants in the cognitive interviews highlighted how trust and inclusive and validating language in the survey alleviated concerns related to privacy and representation.

CONCLUSIONS

This study provides promising results regarding the feasibility of using a web-based mapping survey to collect sensitive location information relevant to ending the HIV epidemic. Data collection at several geographic levels will allow for insights into spatial recall of behaviors as well as future sensitivity analysis of the spatial scale of hotspots and network characteristics. This design also promotes the privacy and comfort of participants who provide location information for sensitive topics. Key considerations for implementing this type of survey include trust from participants, community partners, or research teams to overcome concerns related to privacy and comfort. The implementation of similar surveys should consider local characteristics and knowledge when crafting the geospatial components.

Dengue transmission dynamics prediction by combining metapopulation networks and Kalman filter algorithm

Predicting the specific magnitude and the temporal peak of the epidemic of individual local outbreaks is critical for infectious disease control. Previous studies have indicated that significant differences in spatial transmission and epidemic magnitude of dengue were influenced by multiple factors, such as mosquito population density, climatic conditions, and population movement patterns. However, there is a lack of studies that combine the above factors to explain their complex nonlinear relationships in dengue transmission and generate accurate predictions. Therefore, to study the complex spatial diffusion of dengue, this research combined the above factors and developed a network model for spatiotemporal transmission prediction of dengue fever using metapopulation networks based on human mobility. For improving the prediction accuracy of the epidemic model, the ensemble adjusted Kalman filter (EAKF), a data assimilation algorithm, was used to iteratively assimilate the observed case data and adjust the model and parameters. Our study demonstrated that the metapopulation network-EAKF system provided accurate predictions for city-level dengue transmission trajectories in retrospective forecasts of 12 cities in Guangdong province, China. Specifically, the system accurately predicts local dengue outbreak magnitude and the temporal peak of the epidemic up to 10 wk in advance. In addition, the system predicted the peak time, peak intensity, and total number of dengue cases more accurately than isolated city-specific forecasts. The general metapopulation assimilation framework presented in our study provides a methodological foundation for establishing an accurate system with finer temporal and spatial resolution for retrospectively forecasting the magnitude and temporal peak of dengue fever outbreaks. These forecasts based on the proposed method can be interoperated to better support intervention decisions and inform the public of potential risks of disease transmission.

Distributional environmental justice of residential walking space: The lens of urban ecosystem services supply and demand

Urban ecosystem services (UES), as an important concept in nature-based solutions, can effectively mitigate adverse environmental burdens and have great potential in addressing environmental justice issues. However, few studies linking UES with environmental justice have considered both supply and demand sides of UES, particularly at the spatial scale of residential walking space. Against this backdrop, we investigated the distributional justice of supply and demand for urban cooling, flood mitigation, air purification, and outdoor recreation in residential walking spaces in Shanghai among socially vulnerable groups (i.e., elderly residents, children, females, low-income residents, no-hukou residents, and ethnic minorities). We found that (1) the UES supply of residential walking space was much lower than that of non-residential walking space, while the UES demand was much higher than that of non-residential walking space. (2) Higher proportions of ethnic minorities, no-hukou residents, and females in Shanghai were positively correlated with several UES demands but were not positively correlated with ES supply, indicating a higher possibility of unsatisfied UES demand for these disadvantaged groups. Future urban blue-green space planning should pay more attention to the spatial allocation of blue-green space, especially placing more blue-green space around residential walking spaces with high UES demand and with a high proportion of socially disadvantaged groups.

Accounting for space, time, and behavior using GPS derived dynamic measures of environmental exposure

Time-weighted spatial averaging approaches (TWSA) are an increasingly utilized method for calculating exposure using global positioning system (GPS) mobility data for health-related research. They can provide a time-weighted measure of exposure, or dose, to various environments or health hazards. However, little work has been done to compare existing methodologies, nor to assess how sensitive these methods are to mobility data inputs (e.g., walking vs driving), the type of environmental data being assessed as the exposure (e.g., continuous surfaces vs points of interest), and underlying point-pattern clustering of participants (e.g., if a person is highly mobile vs predominantly stationary). Here we contrast three TWSA approaches that have been previously used or recently introduced in the literature: Kernel Density Estimation (KDE), Density Ranking (DR), and Point Overlay (PO). We feed GPS and accelerometer data from 602 participants through each method to derive time-weighted activity spaces, comparing four mobility behaviors: all movement, stationary time, walking time, and in-vehicle time. We then calculate exposure values derived from the various TWSA activity spaces with four environmental layer data types (point, line, area, surface). Similarities and differences across TWSA derived exposures for the sample and between individuals are explored, and we discuss interpretation of TWSA outputs providing recommendations for researchers seeking to apply these methods to health-related studies.

What triggers selective daily mobility among older adults? A study comparing trip and environmental characteristics between observed path and shortest path

Interest is growing in neighborhood effects on health beyond individual's home locations. However, few studies accounted for selective daily mobility bias. Selective mobility of 470 older adults (aged 67-94) living in urban and suburban areas of Luxembourg, was measured through detour percentage between their observed GPS-based paths and their shortest paths. Multilevel negative binomial regression tested associations between detour percentage, trips characteristics and environmental exposures. Detour percentage was higher for walking trips (28%) than car trips (16%). Low-speed areas and connectivity differences between observed and shortest paths vary by transport mode, indicating a potential selective daily mobility bias. The positive effects of amenities, street connectivity, low-speed areas and greenness on walking detour reinforce the existing evidence on older adults' active transportation. Urban planning interventions favoring active transportation will also promote walking trips with longer detours, helping older adults to increase their physical activity levels and ultimately promote healthy aging.

The temporality of geographic contexts: Individual environmental exposure has time-related effects on mood

Research on environmental exposure and its impacts on people's mood has attracted increasing attention. Most studies focus on the spatiality of geographic contexts, but they neglect the influence of temporality in the relationships between environments and mood. To this end, a survey was conducted in January 2019 in Guangzhou, China, and measured data (micro-environments, built environments, EMA records, GPS trajectories, and activity logs) covering a weekday were collected from 125 participants. Then, multiple linear regression models are employed to examine and compare the associations between environments and mood based on three possible types of temporal responses (cumulative response, momentary response, and time-lagged response). The results indicate that there are great differences in environmental mood effects based on different types of temporal responses. Specifically, (i) for three types of temporal responses, exposure to PM_2.5 and noise have mood-blunting effects, whereas exposure to green spaces has mood-augmenting effects. (ii) For two types of temporal responses, higher temperature (in winter) may positively influence individual mood based on cumulative and time-lagged response, and higher POI density can positively affect mood based on cumulative and momentary response. (iii) Relative humidity may not have time-related effects on mood. Although all three types of temporal responses are observed in this study, the most significant manifestation is momentary response. These findings not only enrich theoretical research on environmental mood effects and temporality, but also inform the practice of more refined and humanistic urban planning, environmental governance, and public services.

Survey-derived activity space-based exposures to fast food outlets and their cross-sectional associations with use of fast food outlets, diet quality and BMI

There is a need for conceptual and methodological innovation in food environment-health research. We compared different operationalizations of survey-derived activity space exposures to fast food outlets (FFOs) in associations with use of FFO, diet quality and body mass index (BMI). FFO exposure was determined for home, work and a maximum of sixteen other locations reported by 1728 Dutch adults. Considerable differences in count of FFO between locations were found. Adjusted linear regression analyses resulted in small, unexpected associations with use of FFO, diet quality and BMI, whereby the strength of associations differed between exposure measures. Using home and work areas may be a cost-efficient compromise to capture large parts of the exposure to FFOs.

Investigating where adolescents engage in moderate to vigorous physical activity and sedentary behaviour: An exploratory study

BACKGROUND

There is a persistent lack of understanding on the influence of the environment on behaviour and health. While the environment is considered an important modifiable determinant of health behaviour, past research assessing environments often relies on static, researcher-defined buffers of arbitrary distance. This likely leads to misrepresentation of true environmental exposures. This exploratory study aims to compare researcher-defined and self-drawn buffers in reflecting the spaces and time adolescents engage in physical activity (PA) and sedentary behaviour. It also investigates if adolescent's access the PA facility and greenspace nearest their home or school for PA, as well as examine how much time adolescents spent in PA at any PA facilities and greenspaces.

METHODS

Adolescents (aged 14-18 years; n = 34) were recruited from schools in West Yorkshire, England. Seven consecutive days of global positioning system (GPS) and accelerometer data were collected at 15 second intervals. Using ArcGIS, we compared 30 different researcher-defined buffers including: radial, network and ellipse buffers at 400m, 800m, 1000m, 1600m and 3000m and participant-defined self-drawn neighbourhoods to objectively measured PA and sedentary space and PA time. Location of PA was also compared to Points of Interest data to determine if adolescents use the nearest PA facility or greenspace to their home or school and to examine how much PA was undertaken within these locations.

RESULTS

Our exploratory findings show the inadequacy of researcher-defined buffer size in assessing MVPA space or sedentary space. Furthermore, less than 35% of adolescents used the greenspaces or PA facilities nearest to their home or school. Approximately 50% of time spent in PA did not occur within the home, school, PA facility, or greenspace environments.

CONCLUSION

Our exploratory findings help to begin to quantify the inadequacy of researcher-defined, and self-drawn buffers in capturing adolescent MVPA and sedentary space, as well as time spent in PA. Adolescents often do not use PA facilities and greenspaces nearest their home and school and a large proportion of PA is achieved outside PA facilities and greenspaces. Further research with larger samples are needed to confirm the findings of this exploratory study.

Is social-ecological risk associated with individual HIV risk beliefs and behaviours?: An analysis of Kenyan adolescents' local communities and activity spaces

The places where adolescents live, learn, and play are thought to influence behaviours and health, but we have limited tools for measuring environmental risk on a hyperlocal (e.g. neighbourhood) level. Working with 218 adolescents and their parents/guardians in rural western Kenya, we combined participatory mapping activities with satellite imagery to identify adolescent activity spaces and create a novel measure of social-ecological risks. We then examined the associations between social-ecological risk and individual HIV risk beliefs and behaviours. We found support for the conjecture that social-ecological risks may be associated with individual beliefs and behaviours. As social-ecological risk increased for a sample of Kenyan adolescents, so did their reports of riskier sex beliefs and behaviours, as well as unsupervised outings at night. This study reinforces calls for disease prevention approaches that go beyond emphasising individual behaviour change.

Investigating how researcher-defined buffers and self-drawn neighbourhoods capture adolescent availability to physical activity facilities and greenspaces: An exploratory study

BACKGROUND

Modifying the environment is considered an effective population-level approach for increasing healthy behaviours, but associations remain ambiguous. This exploratory study aims to compare researcher-defined buffers and self-drawn neighbourhoods (SDN) to objectively measured availability of physical activity (PA) facilities and greenspaces in adolescents.

METHODS

Seven consecutive days of GPS data were collected in an adolescent sample of 14-18 year olds (n = 69). Using Points of Interest and greenspace data, availability of PA opportunities within activity spaces were determined. We compared 30 different definitions of researcher-defined neighbourhoods and SDNs to objectively measured availability.

RESULTS

Findings showed low agreement for all researcher-defined buffers in measuring the availability of PA facilities in activity spaces. However, results were less clear for greenspace. SDNs also demonstrate low agreement for capturing availability to the PA environment.

CONCLUSION

This exploratory study highlights the inadequacy of researcher-defined buffers and SDNs to define availability to environmental features.

Who shops at their nearest grocery store? A cross-sectional exploration of disparities in geographic food access among a low-income, racially/ethnically diverse cohort in Central Texas

We examined whether Central Texans shop at their nearest supermarket, how far they travel for groceries, and explored differences by race/ethnicity, urbanicity, motivations for store selection and other demographic characteristics. Using cross-sectional data and GIS, continuous network distances from participants' homes to nearest and usual supermarkets were calculated and multivariate linear regression assessed differences. <19% shopped at their nearest supermarket. Regression models found that urbanicity played a large role in distance traveled to preferred supermarket, but other factors varied by race/ethnicity. Our findings demonstrate racial/ethnic and urbanicity disparities in food access and multiple domains of food access need greater consideration.

Inequalities in children's exposure to alcohol outlets in Scotland: a GPS study

BACKGROUND

Alcohol use is a leading cause of harm in young people and increases the risk of alcohol dependence in adulthood. Alcohol use is also a key driver of rising health inequalities. Quantifying inequalities in exposure to alcohol outlets within the activity spaces of pre-adolescent children-a vulnerable, formative development stage-may help understand alcohol use in later life.

METHODS

GPS data were collected from a nationally representative sample of 10-and-11-year-old children (n = 688, 55% female). The proportion of children, and the proportion of each child's GPS, exposed to alcohol outlets was compared across area-level income-deprivation quintiles, along with the relative proportion of exposure occurring within 500 m of each child's home and school.

RESULTS

Off-sales alcohol outlets accounted for 47% of children's exposure, which was higher than expected given their availability (31% of alcohol outlets). The proportion of children exposed to alcohol outlets did not differ by area deprivation. However, the proportion of time children were exposed showed stark inequalities. Children living in the most deprived areas were almost five times more likely to be exposed to off-sales alcohol outlets than children in the least deprived areas (OR 4.83, 3.04-7.66; P < 0.001), and almost three times more likely to be exposed to on-sales alcohol outlets (OR 2.86, 1.11-7.43; P = 0.03). Children in deprived areas experienced 31% of their exposure to off-sales outlets within 500 m of their homes compared to 7% for children from less deprived areas. Children from all areas received 22-32% of their exposure within 500 m of schools, but the proportion of this from off-sales outlets increased with area deprivation.

CONCLUSIONS

Children have little control over what they are exposed to, so policies that reduce inequities in alcohol availability should be prioritised to ensure that all children have the opportunity to lead healthy lives.

Mental health in urban environments: Uncovering the black box of person-place interactions requires interdisciplinary approaches (Preprint)

Living in urban environments affects individuals' mental health through different pathways. For instance, physical activity and social participation are seen as mediators. However, aiming to understand underlying mechanisms, it is necessary to consider that the individual is interacting with its environment. In this regard, this viewpoint discusses how urban health research benefits from integration of socioecological and interdisciplinary perspectives, combined with innovative ambulatory data assessments that enable researchers to integrate different data sources. It is stated that neither focusing on the objective and accurate assessment of the environment (from the perspective of spatial sciences) nor focusing on subjectively measured individual variables (from the public health as well as a psychosocial perspective) alone is suitable to further develop the field. Addressing person-place interactions requires an interdisciplinary view on the level of theory (eg, which variables should be focused on?), assessment methods (eg, combination of time-varying objective and subjective measures), as well as data analysis and interpretation. Firstly, this viewpoint gives an overview on previous findings addressing the relationship of environmental characteristics to physical activity and mental health outcomes. We emphasize the need for approaches that allow us to appropriately assess the real-time interaction between a person and a specific environment and examine within-subject associations. This requires the assessment of environmental features, the spatial-temporal behavior of the individual, and the subjective experiences of the situation together with other individual factors, such as momentary affective states. Therefore, we finally focused on triggered study designs as an innovative ambulatory data assessment approach that allows us to capture real-time data in predefined situations (eg, while walking through a specific urban area).

Changes in activity locations during the COVID-19 pandemic and associations with depression, anxiety, loneliness, and alcohol use

INTRODUCTION

Restrictions and guidelines to limit the spread of COVID-19 caused considerable and rapid changes to individuals' daily routines. This study examines how activity locations changed during the COVID-19 pandemic and associated social distancing restrictions, and whether these changes were associated with depression, anxiety, loneliness, and alcohol use.

METHODS

A web-based survey was conducted early in the COVID-19 pandemic (May-June 2020) in Allegheny County (Pittsburgh), Pennsylvania. Participants (n = 265) reported visits to activity locations in the last 30 days and retrospectively for February 2020 (pre-pandemic). A principal components analysis was conducted to assess change in utilization of activity locations. Component scores of changes to activity locations were compared by sociodemographics. Poisson and zero-inflated negative binomial models were used to examine the relationship between component scores and pandemic depression symptoms, anxiety symptoms, loneliness, and drinking days.

RESULTS

Five distinct principal components of activity location changes were identified. The first component, characterizing broad reductions in activity locations during the early phases of the pandemic, was associated with increased depression and loneliness.

CONCLUSIONS

Results indicate non-uniform shifts in routine activities during the pandemic and highlight the importance of understanding how changes to the social environment affect individuals' psychological wellbeing and alcohol use.

Engaging Public Health Critical Race Praxis in Local Social Determinants of Health Research: The Youth Health Equity and Action Research Training Program in Portland, OR—yHEARTPDX

The social determinants of health (SDH) have long been considered a core mechanism through which racial health inequities are (re)produced and incubated in the U.S. Moreover, scholars have expressly—and appropriately—named structural racism as a precursor to inequities associated with SDH. However, while research on racial health inequities—SDH-related or otherwise—continues to grow, communities of color remain grossly underrepresented as public health researchers and practitioners. Additionally, although SDH are experienced in a very local sense, much research and practice fails to more deeply and thoroughly engage and center local community knowledges. Thus, much work around SDH and racial health inequities presents, ironically, as structurally racist itself—being done/led mostly by White scholars and in ways that do not “center the margins”. Moreover, in the context of public health practice, youth perspective is seldom centered within local health department (LHD) community SDH assessment efforts. With these challenges in mind, this paper introduces and discusses the development of the youth health equity and action research training (yHEART) program as a model for public health researchers/practitioners to engage public health critical race praxis (PHCRP) to better understand and respond to local SDH in communities of color. Specifically, we highlight the significance of PHCRP principles of “voice” and “social construction of knowledge” in advancing antiracism in research and LHD practice related to local SDH. First, we articulate core conceptual and theoretical groundings that informed the yHEART program’s development and animate its ongoing training and research activities. Second, we outline the program’s core training components and overall process, and provide some brief illustrative examples of work completed during the program’s first iteration—yHEART PDX, Vol.I: Youth Participatory Research on Local Social Determinants of Health. We then close with a discussion that reflects on program strengths, challenges, and implications for SDH and racial health equity research/practice in light of growing calls for an antiracist public health.

Clustering and mapping the first COVID-19 outbreak in France

BACKGROUND

With more than 160 000 confirmed COVID-19 cases and about 30 000 deceased people at the end of June 2020, France was one of the countries most affected by the coronavirus crisis worldwide. We aim to assess the efficiency of global lockdown policy in limiting spatial contamination through an in-depth reanalysis of spatial statistics in France during the first lockdown and immediate post-lockdown phases.

METHODS

To reach that goal, we use an integrated approach at the crossroads of geography, spatial epidemiology, and public health science. To eliminate any ambiguity relevant to the scope of the study, attention focused at first on data quality assessment. The data used originate from official databases (Santé Publique France) and the analysis is performed at a departmental level. We then developed spatial autocorrelation analysis, thematic mapping, hot spot analysis, and multivariate clustering.

RESULTS

We observe the extreme heterogeneity of local situations and demonstrate that clustering and intensity are decorrelated indicators. Thematic mapping allows us to identify five "ghost" clusters, whereas hot spot analysis detects two positive and two negative clusters. Our re-evaluation also highlights that spatial dissemination follows a twofold logic, zonal contiguity and linear development, thus determining a "metastatic" propagation pattern.

CONCLUSIONS

One of the most problematic issues about COVID-19 management by the authorities is the limited capacity to identify hot spots. Clustering of epidemic events is often biased because of inappropriate data quality assessment and algorithms eliminating statistical-spatial outliers. Enhanced detection techniques allow for a better identification of hot and cold spots, which may lead to more effective political decisions during epidemic outbreaks.

Using aggregated mobile phone location data to compare the realised foodscapes of different socio-economic groups

The foodscape (the built food environment) is considered one of the driving factors of the higher burden of obesity and chronic disease observed in low socio-economic status (SES) groups. Traditional data collection methods struggle to accurately capture actual access and exposure to the foodscape (realised foodscape). We assess the use of anonymised mobile phone location data (location data) in foodscape studies by applying them to a case study in Perth, Western Australia to test the hypothesis that lower SES groups have poorer realised foodscapes than high SES groups. Kernel density estimation was used to calculate realised foodscapes of different SES groups and home foodscape typologies, which were compared to home foodscapes of the different groups. The location data enabled us to measure realised foodscapes of multiple groups over an extended period and at the city scale. Low SES groups had poor availability of food outlets, including unhealthy outlets, in their home and realised foodscapes and may be more susceptible to a poor home foodscape because of low mobility.

Natural and built environments and blood pressure of Alpine schoolchildren

BACKGROUND

Early life environments may influence children's blood pressure (BP), but evidence on the combined effects of natural and built environment exposures is scarce. The present study investigates the associations of natural and built environment indicators, traffic noise, and air pollution with BP in children living in Alpine valleys.

METHODS

In 2004/2005, 1251 school children (8-12 years old) were sampled for a cross-sectional survey in several Austrian and Italian mountain valleys. Children's mothers completed a questionnaire. The outcomes of interest were systolic and diastolic BP measured with a calibrated oscillometric device. Indicators of land cover assigned to the residential and school coordinates within 100 and 1000 m included normalized difference vegetation index (NDVI), tree canopy cover, and a broader naturalness indicator titled distance to nature (D2N). The presence of a home garden was also measured via self-report. Imperviousness density served as a proxy for the built environment. Residential air pollution (NO₂) and noise (L_den) from traffic were calculated using bespoke modeling. NO₂, L_den, physical activity, and body mass index (BMI) were treated as mediating pathways.

RESULTS

Higher NDVI and tree cover levels in residential and school surroundings and home gardens were consistently associated with lower BP. The built environment was associated with higher BP. Counterintuitive inverse associations between NO₂ and L_den and BP were also found. Structural equation modeling showed that higher levels of greenspace and presence of a home garden were weakly associated with more outdoor play spaces, and in turn with lower BMI, and ultimately with lower BP.

CONCLUSIONS

Exposure to natural environments may help maintain normal BP in children, while built environment may increase children's BP. Outdoor play and less adiposity in greener areas may mediate some of these associations. Evidence on air pollution and noise remains controversial and difficult to explain.

Residential Food Environment, Household Wealth and Maternal Education Association to Preschoolers' Consumption of Plant-Based Vitamin A-Rich Foods: The EAT Addis Survey in Addis Ababa

Vitamin A deficiency is common among preschoolers in low-income settings and a serious public health concern due to its association to increased morbidity and mortality. The limited consumption of vitamin A-rich food is contributing to the problem. Many factors may influence children's diet, including residential food environment, household wealth, and maternal education. However, very few studies in low-income settings have examined the relationship of these factors to children's diet together. This study aimed to assess the importance of residential food availability of three plant-based groups of vitamin A-rich foods, household wealth, and maternal education for preschoolers' consumption of plant-based vitamin A-rich foods in Addis Ababa. A multistage sampling procedure was used to enroll 5467 households with under-five children and 233 residential food environments with 2568 vendors. Data were analyzed using a multilevel binary logistic regression model. Overall, 36% (95% CI: 34.26, 36.95) of the study children reportedly consumed at least one plant-based vitamin A-rich food group in the 24-h dietary recall period. The odds of consuming any plant-based vitamin A-rich food were significantly higher among children whose mothers had a higher education level (AOR: 2.55; 95% CI: 2.01, 3.25), those living in the highest wealth quintile households (AOR: 2.37; 95% CI: 1.92, 2.93), and in residentials where vitamin A-rich fruits were available (AOR: 1.20; 95% CI: 1.02, 1.41). Further research in residential food environment is necessary to understand the purchasing habits, affordability, and desirability of plant-based vitamin A-rich foods to widen strategic options to improve its consumption among preschoolers in low-income and low-education communities.

Delineating the geographic context of physical activities: A systematic search and scoping review of the methodological approaches used in social ecological research over two decades

BACKGROUND

The social ecological approach suggests that the spatial context among other factors influence physical activity behavior. Ample research documents physical environmental effects on physical activity. Yet, to date inconsistent associations remain, which might be explained by conceptual and methodological challenges in measuring the spatial dimensions of health behavior. We review methods applied to measure the spatial contexts in the social ecological physical activity literature.

METHODS

Online databases and selected reviews were used to identify papers published between 1990 and 2020. A total of 2167 records were retrieved, from which 412 studies that used physical activity as a primary outcome variable, included measures of the physical environment and applied the main principles of the social ecological approach, were included.

RESULTS

Subjective approaches were the dominant method to capture the spatial context of physical activities. These approaches were applied in 67% (n=279) of the studies. From the objective approaches an administrative unit was most prevalent and was applied in 29% (n=118) of the studies. The most comprehensive objective spatial methods that capture the true environmental exposure, were used only in 2% (n=10) of the studies.

CONCLUSIONS

Current social ecological physical activity research applies simple conceptualizations and methods of the spatial context. While conceptual and methodological concerns have been repeatedly expressed, no substantive progress has been made in the use of spatial approaches. To further our understanding on place effects on health, future studies should carefully consider the choice of spatial approaches, and their effect on study results.

Neighborhood disadvantage moderates the effect of a mobile health intervention on adolescent depression

This study leverages data from a pilot randomized controlled trial to investigate whether the effectiveness of a text-delivered mHealth intervention targeting adolescent depression and anxiety differs according to residential- and activity space-based measures of exposure to community-level socioeconomic disadvantage. For depression, we find that intervention efficacy is significantly stronger for youth residing in more disadvantaged neighborhoods, even after controlling for individual level socioeconomic status, as well as marginal moderating effects of activity space-based neighborhood disadvantage on treatment efficacy. We do not find evidence of treatment efficacy moderation by neighborhood disadvantage regarding anxiety. While the generalizability of our findings is restricted to this sample and for this intervention, this research serves as a motivating example and initial evidence for how mHealth intervention efficacy can vary by characteristics of the environment, in particular community-level disadvantage. Future clinical research should investigate whether the effectiveness of mHealth interventions may be enhanced by personalization based on an individual's contextual environmental exposures.

The health potential of neighborhoods: A population-wide study in the Netherlands

BACKGROUND

While differences in population health across neighborhoods with different socioeconomic characteristics are well documented, health disparities across neighborhoods with similar socioeconomic characteristics are less well understood. We aimed to estimate population health inequalities, both within and between neighborhoods with similar socioeconomic status, and assessed the association of neighborhood characteristics and socioeconomic spillover effects from adjacent neighborhoods.

METHODS

Based on Dutch whole-population data we determined the percentage of inhabitants with good or very good self-assessed health (SAH) and the percentage of inhabitants with at least one chronic disease (CD) in 11,504 neighborhoods. Neighborhoods were classified by quintiles of a composite neighborhoods socioeconomic status score (NSES). A set of spatial models was estimated accounting for spatial effects in the dependent, independent, and error components of the model.

RESULTS

Substantial population health disparities in SAH and CD both within and between neighborhoods NSES quintiles were observed, with the largest SAH variance in the lowest NSES group. Neighborhoods adjacent to higher SES neighborhoods showed a higher SAH and a lower prevalence of CD. Projected impacts from the spatial regressions indicate how modest changes in NSES among the lowest socioeconomic neighborhoods can contribute to population health in both low- and high-SES neighborhoods.

CONCLUSION

Population health differs substantially among neighborhoods with similar socioeconomic characteristics, which can partially be explained by a spatial socio-economic spillover effect.

Associations between neighbourhood built characteristics and sedentary behaviours among Canadian men and women: findings from Alberta's Tomorrow Project

Evidence of associations between neighbourhood built characteristics and sedentary behaviours is mixed. The study aim was to investigate the associations between objectively-derived neighbourhood built characteristics and self-reported sedentary behaviours among Canadian men and women. This study sourced survey data from Alberta's Tomorrow Project (2008; n = 14,785), in which sitting and motor vehicle travel times during the last 7 days was measured. Geographic Information System was used to calculate neighbourhood built characteristics within a 400 m buffer of participant's home and a walkability score was estimated. To estimate the associations between neighbourhood characteristics and sedentary behaviours, covariate-adjusted generalized linear regression models were used. Walkability, 3-way intersections, and population count were positively associated with sitting time. Business destinations and greenness were negatively associated with sitting time. Walkability, 3-way, and 4-way intersections were negatively associated with motor vehicle travel time. Sex-specific associations between neighbourhood characteristics and sedentary behaviour were found. Among men, business destinations were negatively associated with sitting time, and 3-way intersections, population count, and walkability were negatively associated with motor vehicle travel time. Among women, Normalized Difference Vegetation Index was negatively associated with sitting time. Interventions to reduce sedentary behaviours may need to target neighbourhoods that have built characteristics which might support these behaviours. More research is needed to disentangle the complex relationships between different neighbourhood built characteristics and specific types of sedentary behaviour.

Geospatial Analysis of Neighborhood Environmental Stress in Relation to Biological Markers of Cardiovascular Health and Health Behaviors in Women: Protocol for a Pilot Study

Background

Innovative analyses of cardiovascular (CV) risk markers and health behaviors linked to neighborhood stressors are essential to further elucidate the mechanisms by which adverse neighborhood social conditions lead to poor CV outcomes. We propose to objectively measure physical activity (PA), sedentary behavior, and neighborhood stress using accelerometers, GPS, and real-time perceived ecological momentary assessment via smartphone apps and to link these to biological measures in a sample of White and African American women in Washington, DC, neighborhoods.

Objective

The primary aim of this study is to test the hypothesis that living in adverse neighborhood social conditions is associated with higher stress-related neural activity among 60 healthy women living in high or low socioeconomic status neighborhoods in Washington, DC. Sub-aim 1 of this study is to test the hypothesis that the association is moderated by objectively measured PA using an accelerometer. A secondary objective is to test the hypothesis that residing in adverse neighborhood social environment conditions is related to differences in vascular function. Sub-aim 2 of this study is to test the hypothesis that the association is moderated by objectively measured PA. The third aim of this study is to test the hypothesis that adverse neighborhood social environment conditions are related to differences in immune system activation.

Methods

The proposed study will be cross-sectional, with a sample of at least 60 women (30 healthy White women and 30 healthy Black women) from Wards 3 and 5 in Washington, DC. A sample of the women (n=30) will be recruited from high-income areas in Ward 3 from census tracts within a 15% of Ward 3’s range for median household income. The other participants (n=30) will be recruited from low-income areas in Wards 5 from census tracts within a 15% of Ward 5’s range for median household income. Finally, participants from Wards 3 and 5 will be matched based on age, race, and BMI. Participants will wear a GPS unit and accelerometer and report their stress and mood in real time using a smartphone. We will then examine the associations between GPS-derived neighborhood variables, stress-related neural activity measures, and adverse biological markers.

Results

The National Institutes of Health Institutional Review Board has approved this study. Recruitment will begin in the summer of 2021.

Conclusions

Findings from this research could inform the development of multilevel behavioral interventions and policies to better manage environmental factors that promote immune system activation or psychosocial stress while concurrently working to increase PA, thereby influencing CV health.

International Registered Report Identifier (IRRID)

PRR1-10.2196/29191

Allostatic Load and Exposure Histories of Disadvantage

The stress pathway posits that those in disadvantaged circumstances are exposed to a higher degree of stressful experiences over time resulting in an accumulated biological burden which subsequently relates to poorer health. Trajectories of disadvantage, in the form of neighbourhood deprivation and structural social capital, are evaluated in their relation to allostatic load representing the cumulative “wear and tear” of chronic stress. This paper uses data from the British Household Panel Survey and Understanding Society in a latent class growth analysis. We identify groups of exposure trajectories over time using these classes to predict allostatic load at the final wave. The results show that persistent exposure to higher deprivation is related to worse allostatic load. High structural social capital over time relates to lower allostatic load, in line with a stress buffering effect, though this relationship is not robust to controlling for individual sociodemographic characteristics. By demonstrating a gradient in allostatic load by histories of deprivation, this analysis supports a biological embedding of disadvantage through chronic exposure to stressful environments as an explanation for social health inequalities.

Associations of the Neighborhood Built Environment With Physical Activity Across Pregnancy

BACKGROUND

Several features of the neighborhood built environment have been shown to promote leisure-time physical activity (PA) in the general population, but few studies have examined its impact on PA during pregnancy.

METHODS

Data were extracted from 8362 Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be cohort participants (2010-2013). Residential address information was linked to 3 built environment characteristics: number of gyms and recreation areas within a 3-km radius of residence and census block level walkability. Self-reported leisure-time PA was measured in each trimester and dichotomized as meeting PA guidelines or not. Relative risks for cross-sectional associations between neighborhood characteristics and meeting PA guidelines were estimated using Poisson regression.

RESULTS

More gyms and recreation areas were each associated with a greater chance of meeting PA guidelines in models adjusted for sociodemographic characteristics and preexisting conditions. Associations were strongest in the third trimester where each doubling in counts of gyms and recreation areas was associated with 10% (95% confidence interval, 1.07-1.13) and 8% (95% confidence interval, 1.03-1.12), respectively, greater likelihood of meeting PA guidelines. Associations were similar though weaker for walkability.

CONCLUSIONS

Results from a large, multisite cohort suggest that these built environment characteristics have similar PA-promoting benefits in pregnant women as seen in more general populations.