Youth activity spaces and daily exposure to tobacco outlets

Tobacco retailer density and smoking behaviour: how are exposure and outcome measures classified? A systematic review

INTRODUCTION

To date only a limited number of reviews have focused on how exposure and outcome measures are defined in the existing literature on associations between tobacco retailer density ('density') and smoking behaviour ('smoking'). Therefore this systematic review classified and summarised how both density and smoking variables are operationalised in the existing literature, and provides several methodological recommendations for future density and smoking research.

METHODS

Two literature searches between March and April 2018 and April 2022 were conducted across 10 databases. Inclusion and exclusion criteria were developed and keyword database searches were undertaken. Studies were imported into Covidence. Cross-sectional studies that met the inclusion criteria were extracted and a quality assessment was undertaken. Studies were categorised according to the density measure used, and smoking was re-categorised using a modified classification tool.

RESULTS

Large heterogeneity was found in the operationalisation of both measures in the 47 studies included for analysis. Density was most commonly measured directly from geocoded locations using circular buffers at various distances (n = 14). After smoking was reclassified using a smoking classification tool, past-month smoking was the most common smoking type reported (n = 26).

CONCLUSIONS

It is recommended that density is measured through length-distance and travel time using the street network and weighted (e.g. by the size of an area), or by using Kernel Density Estimates as these methods provide a more accurate measure of geographical to tobacco and e-cigarette retailer density. The consistent application of a smoking measures classification tool, such as the one developed for this systematic review, would enable better comparisons between studies. Future research should measure exposure and outcome measures in a way that makes them comparable with other studies.

IMPLICATIONS

This systematic review provides a strong case for improving data collection and analysis methodologies in studies assessing tobacco retailer density and smoking behaviour to ensure that both exposure and outcome measures are clearly defined and captured. As large heterogeneity was found in the operationalisation of both density and smoking behaviour measures in the studies included for analysis, there is a need for future studies to capture, measure and classify exposure measures accurately, and to define outcome measures in a manner that makes them comparable with other studies.

Objective and perceived measures of tobacco marketing are uniquely associated with cigar use

BACKGROUND

Few studies have examined associations between perceived and objective exposure to tobacco marketing and cigar use, which is the second most commonly used tobacco product by youth.

METHODS

We used Geographic Ecological Momentary Assessment data over 14 days from youth aged 16-20 years (n=83 participants, n=948 observations; 34% past month users of any tobacco product) in eight city areas in California. Tobacco outlets in study cities were visited by trained observers to record outlet Global Positioning System (GPS) point locations and outdoor tobacco marketing. We assessed daily perceived exposure to tobacco marketing within participants' activity spaces; daily objective exposure to tobacco outlets with outdoor marketing within 50 m of activity space polylines (number of outlets and time spent near outlets) and daily cigar use excluding and including blunts.

RESULTS

Controlling for demographics and baseline tobacco use, results from mixed logistic regression models showed that greater perceived exposure to tobacco marketing was positively associated with higher odds of cigar use each day, excluding blunts (adjusted odds ratios (aOR): 2.00; 95% CI 1.03 to 3.87) and including blunts (aOR: 1.87; 95% CI 1.26 to 2.77). Also, exposure to a greater number of tobacco outlets with outdoor marketing was associated with higher odds of cigar use each day, excluding blunts (aOR: 1.34; 95% CI 1.01 to 1.78), but not including blunts.

CONCLUSIONS

Tobacco control efforts should consider both perceived and objective exposure to tobacco marketing and unique associations with blunt use to prevent cigar use.

Feasibility and acceptability of mobile methods to assess home and neighborhood environments related to adolescent sleep

OBJECTIVE

A growing evidence base suggests home and neighborhood environmental exposures may influence adolescent sleep, but few studies have assessed these relationships using methods that account for time-varying, location-specific exposures, or multiple neighborhood contexts. This study aimed to assess the feasibility and acceptability of using smartphone global positioning system (GPS) tracking and ecological momentary assessment (EMA) to assess time-varying home and neighborhood environmental exposures hypothesized to be associated with adolescent sleep.

METHODS

Adolescents aged 15-17 years in Philadelphia completed 7 days of continuous smartphone GPS tracking, which was used to identify daily levels of exposure to geocoded neighborhood factors (eg, crime, green space). Four daily EMA surveys assessed home sleep environment (eg, noise, light), stress, health behaviors, and neighborhood perceptions. Feasibility and acceptability of GPS tracking and EMA were assessed, and distributions of daily environmental exposures were examined.

RESULTS

Among 25 teens (mean age 16, 56% male), there was a high level of GPS location data captured (median daily follow-up: 24 hours). Seventy-eight percent of EMA surveys were completed overall. Most participants (96%) reported no privacy concerns related to GPS tracking and minimal burden from EMA surveys. Exposures differed between participants' home neighborhoods and locations visited outside the home neighborhood (eg, higher crime away from home). Sleep environment disruptions were present on 29% of nights (most common: uncomfortable temperature) and were reported by 52% of adolescents.

CONCLUSIONS

Results demonstrate the feasibility and acceptability of mobile methods for assessing time-varying home and neighborhood exposures relevant to adolescent sleep for up to 1 week.

Proximity of IQOS and JUUL points of sale to schools in Israel: a geospatial analysis

SIGNIFICANCE

Exploring proximity and density of heated tobacco product (HTP) and electronic nicotine delivery system (ENDS) points of sale (POS) to schools is critical for understanding youth marketing exposure and informing policy and enforcement to protect youth. This study examined IQOS and JUUL POS (prominent HTPs and ENDS), specifically their proximity to and density around schools in Israel.

METHODS

Using geospatial analysis and IQOS/JUUL website data, distance matrices were used to calculate distance from each school in Israel (grades 1-12) to the nearest POS and number of POS within 1 km, accounting for schools' neighbourhood socioeconomic status (SES) ranking.

RESULTS

An average of 8.7 IQOS POS and 5.2 JUUL POS were within walking distance (1 km) from schools. Average distances from schools to nearest IQOS and JUUL POS were 954 m (median=365 m) and 1535 m (median=579 m), respectively. The percentages of schools with at least one IQOS or JUUL POS within 1 km were 86% and 74%, respectively. The average numbers of POS within 1 km of schools in low-SES, middle-SES, and high-SES neighbourhoods were 7.5, 9.9, and 7.6 for IQOS and 4.1, 5.9, and 5.5 for JUUL, respectively. Median distances from schools in low-SES, middle-SES, and high-SES neighbourhoods to nearest POS were 428 m, 325 m, and 403 m for IQOS and 1044 m, 483 m, and 525 m for JUUL.

CONCLUSIONS

Youth experience high environmental exposure to IQOS and JUUL POS, particularly IQOS. POS were more densely located near schools in middle-SES neighbourhoods. Thus, regulating HTP and ENDS POS near schools and in certain neighbourhoods is key to reducing youth population impact in Israel and elsewhere.

Youth tobacco and cannabis use and co-use: Associations with daily exposure to tobacco marketing within activity spaces and by travel patterns

BACKGROUND

We investigated youth daily activity spaces, travel patterns, exposure to tobacco retail marketing, and tobacco and cannabis use and co-use.

METHODS

Data included 1,060 daily assessments from 100 participants (16-20 years old) in 8 California cities. Using GPS-enabled smartphones with a survey application, youth completed brief daily surveys, and location coordinates were obtained at one-minute intervals. Tobacco outlets in study cities were visited by observers to record outlet GPS point locations and data concerning tobacco marketing. Tobacco outlet addresses and GPS location coordinates were geocoded. Activity spaces were constructed by joining sequential location points. Measures included the number of outlets with outdoor tobacco marketing within 50 m of activity space polylines and the amount of time participants were within 50 m of these outlets each day. Participants also reported tobacco and cannabis use and whether they saw tobacco ads by their neighborhood, school, workplace, and anywhere else each day. Additionally each day they reported how much time they traveled by different modes of transportation, with parents/guardians, and with friends.

RESULTS

In mixed effects multinomial regression models, perceived exposure to tobacco marketing was associated with co-use of tobacco and cannabis on a given day (RRR = 1.66, p < 0.05). Although perceived exposure to tobacco marketing was not associated with tobacco use only, moderation analysis indicated that the likelihood of tobacco use was greater among youth who walked/biked/skated more (RRR = 5.22, p < 0.05).

CONCLUSION

Perceived exposure to tobacco marketing contributes to youth tobacco and cannabis use or co-use, especially for those who travel by walking/biking/skating.

Redefining Exposure: Using Mobile Technology and Geospatial Analysis to Explore When and Where Chicago Adolescents are Exposed to Neighborhood Characteristics

Differences in how individuals navigate and interact with physical space have clear implications for when and where they are exposed to environmental characteristics. To address this reality, we propose and test a novel method with a sample of Chicago adolescents that links individual GPS coordinates with locations of environmental characteristics as a strategy to increase precision in the measurement of environmental exposures. We use exposure to violent crime as an example and link the GPS coordinates of 51 youth collected over a one-week period during the summer of 2016 to locations and times of violent crime. We explore different spatial and temporal parameters to determine whether an exposure occurred. Using the 660-foot (201 m), 24-hour operationalization, we found that youth were exposed to a total of 126 violent crimes, with an average of 3.82 (SD = 3.24) per respondent. This was higher than the 12 that were identified when exposure was calculated as the number of violent crimes occurring within 660 feet (201 m) of youths' residential addresses during the week-long assessment period. Examining correlations between the different exposure variables and measures of youths' psychological functioning, we found the largest relationships when using the GPS-based indices. We present a strategy for measuring exposure to environmental characteristics using GPS data. Higher rates of crime exposure are found based on GPS coordinates than with residential address. GPS-based exposure measures are related to youths' psychological functioning.

Tobacco Retail Environment and Smoking: A Systematic Review of Geographic Exposure Measures and Implications for Future Studies

INTRODUCTION

To review the geographic exposure measures used to characterize the tobacco environment in terms of density of tobacco outlets and proximity to tobacco outlets, and its association with smoking-related outcomes.

METHODS

We used PubMed and Google Scholar to find articles published until December 2019. The search was restricted to studies that (1) measured the density of and/or proximity to tobacco outlets and (2) included associations with smoking outcomes. The extraction was coordinated by several observers. We gathered data on the place of exposure, methodological approaches, and smoking outcomes.

RESULTS

Forty articles were eligible out of 3002 screened papers. Different density and proximity measures were described. 47.4% density calculations were based on simple counts (number of outlets within an area). Kernel density estimations and other measures weighted by the size of the area (outlets per square kilometer), population, and road length were identified. 81.3% of the articles which assessed proximity to tobacco outlets used length distances estimated through the street network. Higher density values were mostly associated with higher smoking prevalence (76.2%), greater tobacco use and smoking initiation (64.3%), and lower cessation outcomes (84.6%). Proximity measures were not associated with any smoking outcome except with cessation (62.5%).

CONCLUSION

Associations between the density of tobacco outlets and smoking outcomes were found regardless of the exposure measure applied. Further research is warranted to better understand how proximity to tobacco outlets may influence the smoking outcomes. This systematic review discusses methodological gaps in the literature and provides insights for future studies exploring the tobacco environment.

IMPLICATIONS

Our findings pose some methodological lessons to improve the exposure measures on the tobacco outlet environment. Solving these methodological gaps is crucial to understand the influence of the tobacco environment on the smoking outcomes. Activity spaces should be considered in further analyses because individuals are exposed to tobacco beyond their residence or school neighborhood. Further studies in this research area demand density estimations weighted by the size of the area, population, or road length, or measured using Kernel density estimations. Proximity calculations should be measured through the street network and should consider travel times apart from the length distance.

The Association Between Tobacco Outlet Density and Smoking Among Young People: A Systematic Methodological Review

Aim

Evidence on the association between tobacco outlet density and proximity and smoking behavior among youth is inconsistent, which may be due to methodological problems in some studies. We assessed the association of outlet density or proximity with smoking behavior among young people while taking into account the methodological quality of studies.

Methods

MEDLINE, EMBASE, and Google Scholar were systematically searched for studies on the relationship between outlet density or proximity and smoking behavior among 12- to 25-year-olds, published between 1997 and 2017. Methodological quality of the included studies was evaluated independently by two reviewers.

Results

Twenty studies were included in the review. The quality assessment identified five primary sources of potential bias: overadjustment for mediators (problems identified in 14 studies), underadjustment for confounders (six studies), poor statistical model fit (four studies), selection bias (three studies), and misclassification of exposure measurements (eight studies). Four studies were of high methodological quality. In studies with relatively high quality, 10 associations were reported, of which seven were nonsignificant, two positive, and one negative. Similarly, the complete body of evidence demonstrated mostly nonsignificant associations, but a larger proportion of positive associations than negative.

Conclusion

Although there is some support for a positive direction, current literature does not provide consistent evidence for a positive association between outlet density and smoking among youth. This is not necessarily due to bias in specific studies, but more to fundamental challenges in study design and exposure measurements. These issues need to be addressed in future studies using more rigorous methods.

Implications

Our findings suggest that, although there is some evidence for a positive association, current scientific literature does not provide consistent support to claim an effect of tobacco outlet density or proximity on youth smoking. This underlines the need for more research with improved methodology. There is a need for quasiexperimental studies, in which the outlet density changes substantially, studies measuring the actual exposure of youth to tobacco outlets, and qualitative research on the mechanisms underlying any association.

Association between density and proximity of tobacco retail outlets with smoking: A systematic review of youth studies

BACKGROUND

Reducing the retail availability of tobacco has been proposed as a component of tobacco endgame, yet it is not known whether retail availability has a direct impact on smoking behaviours. A narrative review and a meta-analysis have been undertaken to examine the density and proximity of tobacco retail outlets, but were limited in scope, exposure and outcome variables. The aim of this current study was to undertake a systematic review of the international literature on the density and proximity of tobacco retail outlets to homes, schools and communities and their association with smoking behaviours among youth.

METHODS

We reviewed and critically appraised the evidence documenting the association between density or proximity of tobacco retail outlets and smoking behaviours among school-age youth (18 and under), between 1 January 1990 and 21 October 2019. We reviewed original quantitative research that examined the associations of tobacco retail outlet density and proximity with individual smoking status or population-level smoking prevalence; initiation of smoking; frequency of tobacco use; sales to minors; purchasing by minors; susceptibility to smoking among non-smokers; perceived prevalence of smoking, and quitting behaviours.

FINDINGS

Thirty-five peer-reviewed papers met the inclusion criteria. This review provided evidence of a relationship between density of tobacco retail outlets and smoking behaviours, particularly for the density near youths' home. A study using activity spaces also found a significant positive association between exposure to tobacco retail outlets and daily tobacco use. The review did not provide evidence of an association between the proximity of tobacco retail outlets to homes or schools and smoking behaviours among youth.

CONCLUSIONS

The existing evidence supports a positive association between tobacco retail outlet density and smoking behaviours among youth, particularly for the density near youths' home. This review provides evidence for the development and implementation of policies to reduce the density of tobacco retail outlets to reduce smoking prevalence among youth.

Is Smoking Cessation in Young Adults Associated With Tobacco Retailer Availability in Their Activity Space?

INTRODUCTION

The presence of tobacco retailers in residential neighborhoods has been inversely associated with residents' likelihood of quitting smoking. Few studies have yet explored whether this association holds when accounting for tobacco retailers found in the multiple environments where people conduct their daily activities, that is, their activity space.

METHODS

We analyzed cross-sectional data from 921 young adults (18- to 25-years old) participating in the Interdisciplinary Study of Inequalities in Smoking (Montreal, Canada). Respondents self-reported sociodemographic, smoking, and activity location data. Log-binomial regression was used to estimate prevalence ratios (PRs) for the association between smoking cessation and (1) the number of tobacco retailers (counts), and (2) the distance to the closest retailer (proximity) in participants' residential neighborhood and activity space.

RESULTS

Smoking cessation was positively associated with low and intermediate tertile levels of tobacco retailer counts in both the residential neighborhood and activity space, and with the furthest distance level in the activity space [PR (95% CI) = 1.21 (1.02 to 1.43)].

CONCLUSIONS

Individuals encounter resources in the course of their regular daily activities that may hamper smoking cessation. This study highlights the relevance of considering the tobacco retail environment of both individuals' residential neighborhood and activity space to understand its association with smoking cessation.

IMPLICATIONS

This article contributes to the literature on the association between the tobacco retail environment and smoking cessation in young adults by moving beyond the residential neighborhood to also assess individuals' access to tobacco retailers in the multiple areas where they regularly spend time, that is, their activity space. Findings suggest that lower numbers of tobacco retailers in both the residential neighborhood and activity space, and further distance to tobacco retailers in the activity space are associated with increased smoking cessation.

Youth daily exposure to tobacco outlets and cigarette smoking behaviors: does exposure within activity space matter?

AIMS

To examine whether daily exposure to tobacco outlets within activity spaces is associated with cigarette smoking and with the number of cigarettes smoked by youth that day.

DESIGN

The study used geographic ecological momentary assessment (GEMA) data that combined daily surveys with ecological momentary assessment of global positioning systems (GPS) using geographic information systems (GIS) to allow for real-time data collection of participants' environments and behaviors.

SETTING

Eight mid-sized California (USA) city areas.

PARTICIPANTS

The analytical sample included 1065 days, which were clustered within 100 smoker and non-smoker participants (aged 16-20 years, 60% female).

MEASUREMENTS

Any cigarette smoking and number of cigarettes smoked on a given day, the number of tobacco outlets within 100 m of activity space polylines each day, the number of minutes participants spent within 100 m of tobacco outlets each day and demographic characteristics (age, sex, race/ethnicity and perceived socio-economic status).

FINDINGS

Controlling for demographic characteristics, the findings of multi-level mixed effects logistic models were inconclusive, whether or not the number of tobacco outlets within 100 m of youths' activity space polylines or the number of minutes spent within 100 m of tobacco outlets were associated with whether the participant smoked cigarettes on a given day [odds ratio (OR) = 1.05, P = 0.24; OR = 0.99, P = 0.81, respectively]. However, in multi-level zero-inflated negative binomial models, the risk of smoking an additional cigarette on a given day increased with each additional tobacco outlet [incidence rate ratio (IRR) = 1.04, P < 0.05] and each additional minute spent within 100 m of tobacco outlets (IRR = 1.01, P < 0.001) each day.

CONCLUSIONS

Among young people in urban California, differences in day-to-day exposure to tobacco outlets within activity spaces does not seem to be significantly associated with whether a person smokes a cigarette on a given day, but higher exposure to tobacco outlets appears to be positively associated with the number of cigarettes smoked on that day.

The Potential of Smartphone Apps in Informing Protobacco and Antitobacco Messaging Efforts Among Underserved Communities: Longitudinal Observational Study

Background

People from underserved communities such as those from lower socioeconomic positions or racial and ethnic minority groups are often disproportionately targeted by the tobacco industry, through the relatively high levels of tobacco retail outlets (TROs) located in their neighborhood or protobacco marketing and promotional strategies. It is difficult to capture the smoking behaviors of individuals in actual locations as well as the extent of exposure to tobacco promotional efforts. With the high ownership of smartphones in the United States—when used alongside data sources on TRO locations—apps could potentially improve tobacco control efforts. Health apps could be used to assess individual-level exposure to tobacco marketing, particularly in relation to the locations of TROs as well as locations where they were most likely to smoke. To date, it remains unclear how health apps could be used practically by health promotion organizations to better reach underserved communities in their tobacco control efforts.

Objective

This study aimed to demonstrate how smartphone apps could augment existing data on locations of TROs within underserved communities in Massachusetts and Texas to help inform tobacco control efforts.

Methods

Data for this study were collected from 2 sources: (1) geolocations of TROs from the North American Industry Classification System 2016 and (2) 95 participants (aged 18 to 34 years) from underserved communities who resided in Massachusetts and Texas and took part in an 8-week study using location tracking on their smartphones. We analyzed the data using spatial autocorrelation, optimized hot spot analysis, and fitted power-law distribution to identify the TROs that attracted the most human traffic using mobility data.

Results

Participants reported encountering protobacco messages mostly from store signs and displays and antitobacco messages predominantly through television. In Massachusetts, clusters of TROs (Dorchester Center and Jamaica Plain) and reported smoking behaviors (Dorchester Center, Roxbury Crossing, Lawrence) were found in economically disadvantaged neighborhoods. Despite the widespread distribution of TROs throughout the communities, participants overwhelmingly visited a relatively small number of TROs in Roxbury and Methuen. In Texas, clusters of TROs (Spring, Jersey Village, Bunker Hill Village, Sugar Land, and Missouri City) were found primarily in Houston, whereas clusters of reported smoking behaviors were concentrated in West University Place, Aldine, Jersey Village, Spring, and Baytown.

Conclusions

Smartphone apps could be used to pair geolocation data with self-reported smoking behavior in order to gain a better understanding of how tobacco product marketing and promotion influence smoking behavior within vulnerable communities. Public health officials could take advantage of smartphone data collection capabilities to implement targeted tobacco control efforts in these strategic locations to reach underserved communities in their built environment.

How Is Exposure to Tobacco Outlets Within Activity Spaces Associated With Daily Tobacco Use Among Youth? A Mediation Analysis

INTRODUCTION

We investigated associations between exposure to tobacco outlets within activity spaces and daily tobacco use, and whether exposure to adults or peers using tobacco mediate these relationships.

METHODS

We used Geographic Ecological Momentary Assessment data over 14 days from 85 youth aged 16-20 years in eight mid-sized California city areas. Tobacco outlet addresses and global positioning systems locations were geocoded and activity spaces were constructed by joining sequential points. We assessed daily number of tobacco outlets within 50 or 100 m of activity space polylines and number of minutes participants were within 50 or 100 m of tobacco outlets each day; daily use of tobacco; and whether participants saw (1) adults and (2) people their age (peers) using tobacco each day.

RESULTS

Controlling for demographics, results of multilevel structural equation models showed no association between number of tobacco outlets within 50 m of polylines and tobacco use (probit regression coefficient: 0.01, p = .82). However, we found evidence of an indirect effect (p = .001) through daily exposure to peers using tobacco. Specifically, greater number of tobacco outlets within 50 m of polylines was positively associated with seeing peers use tobacco (probit regression coefficient: 0.10, p < .001). In turn, seeing peers use tobacco was positively associated with tobacco use on that day (probit regression coefficient: 2.23, p < .001). Similar results were found for number of tobacco outlets within 100 m of polylines.

CONCLUSIONS

Exposure to tobacco outlets within activity spaces affects youth tobacco use through daily exposure to peers who use tobacco.

IMPLICATIONS

Using real-time-ordered data, this article examines whether exposure to adults and peers using tobacco mediate associations between exposure to tobacco outlets within activity spaces and daily tobacco use among youth. Results suggest that exposure to tobacco outlets within activity spaces affects daily tobacco use through exposure to peers who use tobacco. These findings provide additional significant support for policy makers who are considering regulating the number and density of tobacco retailers and point to the importance of interventions focused on peer tobacco use and youths' daily environments to reduce tobacco use.

GIS-modelled built-environment exposures reflecting daily mobility for applications in child health research

Background

Inaccurately modelled environmental exposures may have important implications for evidence-based policy targeting health promoting or hazardous facilities. Travel routes modelled using GIS generally use shortest network distances or Euclidean buffers to represent journeys with corresponding built-environment exposures calculated along these routes. These methods, however, are an unreliable proxy for calculating child built-environment exposures as child route choice is more complex than shortest network routes.

Methods

We hypothesised that a GIS model informed by characteristics of the built-environment known to influence child route choice could be developed to more accurately model exposures. Using GPS-derived walking commutes to and from school we used logistic regression models to highlight built-environment features important in child route choice (e.g. road type, traffic light count). We then recalculated walking commute routes using a weighted network to incorporate built-environment features. Multilevel regression analyses were used to validate exposure predictions to the retail food environment along the different routing methods.

Results

Children chose routes with more traffic lights and residential roads compared to the modelled shortest network routes. Compared to standard shortest network routes, the GPS-informed weighted network enabled GIS-based walking commutes to be derived with more than three times greater accuracy (38%) for the route to school and more than 12 times greater accuracy (92%) for the route home.

Conclusions

This research advocates using weighted GIS networks to accurately reflect child walking journeys to school. The improved accuracy in route modelling has in turn improved estimates of children’s exposures to potentially hazardous features in the environment. Further research is needed to explore if the built-environment features are important internationally. Route and corresponding exposure estimates can be scaled to the population level which will contribute to a better understanding of built-environment exposures on child health and contribute to mobility-based child health policy.

Socioeconomic inequalities in children's exposure to tobacco retailing based on individual-level GPS data in Scotland

BACKGROUND

Identifying factors shaping knowledge of and attitudes towards tobacco products in preadolescence is a key component supporting tobacco control policies aimed at preventing smoking initiation. This study quantified exposure to tobacco retailing environments within the individual-level activity spaces of children across a socioeconomic gradient.

METHODS

One week of global positioning system (GPS) tracking data were collected at 10 s intervals from a nationally representative sample of 10-11-year olds (n=692). Proximity of GPS locations (n=~16 M) to the nearest tobacco retailer (n=9030) was measured and exposure defined when a child came within 10 m of a retailer. Duration, frequency, timing and source of exposure were compared across income deprivation quintiles, along with retail density within children's home neighbourhoods.

RESULTS

On average, children were exposed to tobacco retailing for 22.7 min (95% CI 16.8 to 28.6) per week in 42.7 (35.2-50.1) independent encounters. However, children from the most deprived areas accumulated six times the duration and seven times the frequency of exposure as children from the least deprived areas. Home neighbourhood retail densities were 2.6 times higher in deprived areas, yet the average number of businesses encountered did not differ. Most exposure came from convenience stores (35%) and newsagents (15%), with temporal peaks before and after school hours.

CONCLUSIONS

By accounting for individual mobility, we showed that children in socially disadvantaged areas accumulate higher levels of exposure to tobacco retailing than expected from disparities in home neighbourhood densities. Reducing tobacco outlet availability, particularly in areas frequently used by children, might be crucial to policies aimed at creating 'tobacco-free' generations.

Assessing Individuals' Exposure to Environmental Conditions Using Residence-based Measures, Activity Location-based Measures, and Activity Path-based Measures

BACKGROUND

Many approaches are available to researchers who wish to measure individuals' exposure to environmental conditions. Different approaches may yield different estimates of associations with health outcomes. Taking adolescents' exposure to alcohol outlets as an example, we aimed to (1) compare exposure measures and (2) assess whether exposure measures were differentially associated with alcohol consumption.

METHODS

We tracked 231 adolescents 14-16 years of age from the San Francisco Bay Area for 4 weeks in 2015/2016 using global positioning systems (GPS). Participants were texted ecologic momentary assessment surveys six times per week, including assessment of alcohol consumption. We used GPS data to calculate exposure to alcohol outlets using three approach types: residence-based (e.g., within the home census tract), activity location-based (e.g., within buffer distances of frequently attended places), and activity path-based (e.g., average outlets per hour within buffer distances of GPS route lines). Spearman correlations compared exposure measures, and separate Tobit models assessed associations with the proportion of ecologic momentary assessment responses positive for alcohol consumption.

RESULTS

Measures were mostly strongly correlated within approach types (ρ ≥ 0.7), but weakly (ρ < 0.3) to moderately (0.3 ≤ ρ < 0.7) correlated between approach types. Associations with alcohol consumption were mostly inconsistent within and between approach types. Some of the residence-based measures (e.g., census tract: β = 8.3, 95% CI = 2.8, 13.8), none of the activity location-based approaches, and most of the activity path-based approaches (e.g., outlet-hours per hour, 100 m buffer: β = 8.3, 95% CI = 3.3, 13.3) were associated with alcohol consumption.

CONCLUSIONS

Methodologic decisions regarding measurement of exposure to environmental conditions may affect study results.

How many days of global positioning system (GPS) monitoring do you need to measure activity space environments in health research?

This study examined the number of days of global positioning system (GPS) monitoring needed to measure attributes of an individual's routine activity space. Multiple alternative activity space representations (cumulative, mean daily), measures (kernel density, route buffer, convex hull), and attributes (area size, supermarkets, fast food restaurants, parks) were examined. Results suggested wide variability in required GPS days to obtain valid estimates of activity space attributes (1-23 days). In general, fewer days were needed for mean daily activity space representations, kernel density measures, and densities of environmental exposures (vs. counts). While kernel density measures reliably estimated between-person differences in attributes after just a few days, most variability in environmental attributes for convex hull and route buffer measures was within-person. Based on these results, a minimum of 14 days of valid GPS data is recommended to measure activity spaces.

Tobacco outlet density and adolescents' cigarette smoking: a meta-analysis

OBJECTIVE

We conducted meta-analyses of studies that investigated the associations between tobacco outlet density around homes and schools and adolescents' past-month cigarette smoking.

DATA SOURCES

Systematic literature searches of eight databases were carried out in February 2017. Searches were not limited by date, language, country or peer-reviewed status.

STUDY SELECTION

After screening for quality, studies that examined the relationship between tobacco outlet density and adolescents' past-month smoking were selected for inclusion.

DATA EXTRACTION

Two investigators screened study abstracts and full texts and independently extracted data. Consensus was reached at each stage.

DATA SYNTHESIS

Random-effects meta-analyses were conducted on 11 studies that provided 13 effect sizes. Results showed that there was a significant association between tobacco outlet density around homes and adolescents' past-month smoking behaviour, with an overall effect size of OR=1.08 (95% CI 1.04 to 1.13; P<0.001; I2=0%). For density around schools, the association was not statistically significant (OR=1.01, 95% CI 0.98 to 1.03; P=0.53; I2=39%).

CONCLUSIONS

These findings suggest that exposure to tobacco outlets near home environments may be important for understanding adolescents' past-month smoking. Restricting access to tobacco outlets and controlling the number of outlets in residential areas may be an effective preventive strategy to help reduce adolescents' smoking.

An Analytical Framework for Integrating the Spatiotemporal Dynamics of Environmental Context and Individual Mobility in Exposure Assessment: A Study on the Relationship between Food Environment Exposures and Body Weight

In past studies, individual environmental exposures were largely measured in a static manner. In this study, we develop and implement an analytical framework that dynamically represents environmental context (the environmental context cube) and effectively integrates individual daily movement (individual space-time tunnel) for accurately deriving individual environmental exposures (the environmental context exposure index). The framework is applied to examine the relationship between food environment exposures and the overweight status of 46 participants using data collected with global positioning systems (GPS) in Columbus, Ohio, and binary logistic regression models. The results indicate that the proposed framework generates more reliable measurements of individual food environment exposures when compared to other widely used methods. Taking into account the complex spatial and temporal dynamics of individual environmental exposures, the proposed framework also helps to mitigate the uncertain geographic context problem (UGCoP). It can be used in other environmental health studies concerning environmental influences on a wide range of health behaviors and outcomes.

The tobacco endgame: The neglected role of place and environment

An increasing number of countries across the world are planning for the eradication of the tobacco epidemic. The actions necessary to realise this ambition have been termed the tobacco endgame. The focus of this paper is on the intersection between the tobacco endgame with place, a neglected theme in recent academic and policy debates. We begin with an overview of the key themes in the literature on endgame strategies before detailing the international landscape of engame initiatives, paying particular attention to the opportunities and challenges of endgame strategies in low and middle income countries. Finally, we critically assess the current endgame debates and suggest a novel agenda for integrating geographical perspectives into research on the endgame that provides enhanced understanding of the challenges associated with this important global health vision.

Using Individual GPS Trajectories to Explore Foodscape Exposure: A Case Study in Beijing Metropolitan Area

With the growing interest in studying the characteristics of people’s access to the food environment and its influence upon individual health, there has been a focus on assessing individual food exposure based on GPS trajectories. However, existing studies have largely focused on the overall activity space using short-period trajectories, which ignores the complexity of human movements and the heterogeneity of the spaces that are experienced by the individual over daily life schedules. In this study, we propose a novel framework to extract the exposure areas consisting of the localized activity spaces around daily life centers and non-motorized commuting routes from long-term GPS trajectories. The newly proposed framework is individual-specific and can incorporate the internal heterogeneity of individual activities (spatial extent, stay duration, and timing) in different places as well as the dynamics of the context. A pilot study of the GeoLife dataset suggests that there are significant variations in the magnitude as well as the composition of the food environment in different parts of the individual exposure area, and residential environment is not representative of the overall foodscape exposure.

Tobacco outlet density and tobacco knowledge, beliefs, purchasing behaviours and price among adolescents in Scotland

Despite long-term falls in global adult smoking prevalence and over 50 years of tobacco control policies, adolescent smoking persists. Research suggests greater densities of tobacco retail outlets in residential neighbourhoods are associated with higher adolescent smoking rates. Policies to reduce retail outlets have therefore been identified by public health researchers as a potential 'new frontier' in tobacco control. Better understanding of the pathways linking density of tobacco retailers and smoking behaviour could support these policies. In this study we use path analysis to assess how outlet density in the home environment is related to adolescent tobacco knowledge, beliefs, retail purchases and price in Scotland. We assessed 22,049 13 and 15 year old respondents to the nationally representative cross-sectional 2010 Scottish School Adolescent Lifestyle and Substance Use Survey. Outlet density was based on Scottish Tobacco Retailers Register, 2012, data. A spatially-weighted Kernel Density Estimation measure of outlet density within 400 m of respondents' home postcode was grouped into tertiles. The analysis considered whether outlet density was associated with the number of cigarette brands adolescents could name, positive beliefs about smoking, whether smokers purchased cigarettes from shops themselves or through adult proxies and perceived cost of cigarettes. Models were stratified by adolescent smoking status. The path analyses indicated that outlet density was not associated with most outcomes, but small, significant direct effects on knowledge of cigarette brands among those who had never smoked were observed. With each increase in outlet density tertile the mean number of brands adolescents could name rose by 0.07 (mean = 1.60; SD = 1.18; range = 4). This suggests greater outlet densities may have affected adolescents' knowledge of cigarette brands but did not encourage positive attitudes to smoking, purchases from shops or lower cigarette prices. Exposure to tobacco outlets may influence adolescents' awareness of tobacco products, a potential pathway to smoking behaviour.

The places parents go: understanding the breadth, scope, and experiences of activity spaces for parents

Neighborhood environments are related to parenting behaviors, which in turn have a life-long effect on children's health and well-being. Activity spaces, which measure individual routine patterns of movement, may be helpful in assessing how physical and social environments shape parenting. In this study we use qualitative data and GIS mapping from 4 California cities to examine parental activity spaces. Parents described a number of factors that shape their activity spaces including caregiving status, the age of their children, and income. Parental activity spaces also varied between times (weekends vs. weekdays) and places (adult-only vs. child-specific places). Knowing how to best capture and study parental activity spaces could identify mechanisms by which environmental factors influence parenting behaviors and child health.

A momentary exposures analysis of proximity to alcohol outlets and risk for assault

AIMS

This study estimated, with high spatial and temporal specificity, individuals' risk of being assaulted relative to their momentary proximity to alcohol outlets during daily activities.

DESIGN

Case-control study.

SETTING

Philadelphia, PA, USA.

PARTICIPANTS

Cases were 194 non-gun assault victims and 135 gun assault victims aged between 10 and 24 years. Age-matched controls (n = 274) were selected using random-digit dialing.

MEASUREMENTS

Participants described minute-by-minute movements (i.e. activity paths) during the course of the day of the assault (cases) or a recent randomly selected day within 3 days of interview (controls). The dependent measure was being an assault case compared with a non-assault control. The main independent measures were participants' momentary proximity to alcohol outlets. The units of analysis were 10-minute segments beginning at 4:00 a.m.

FINDINGS

Proximity to bars and restaurants was associated with decreased odds of non-gun assault before 1 p.m. [e.g. 7 a.m. to 9:59 a.m.: odds ratio (OR) = 0.78; 95% confidence interval (CI) = 0.64, 0.94; P = 0.008], and increased odds after 7 p.m. (e.g. 1 a.m. to 3:59 a.m.: OR = 1.96; 95% CI = 1.24, 3.09; P = 0.004). Proximity to beer stores was associated with increased odds before 1 p.m. (e.g. 7 a.m. to 9:59 a.m.: OR = 2.34; 95% CI = 1.58, 3.46; P < 0.001) and from 4 p.m. to 6:59 p.m. (OR = 1.50; 95% CI = 1.14, 1.96; P = 0.004), but decreased odds after 7 p.m. (e.g. 1 a.m. to 3:59 a.m.: OR = 0.28; 95% CI = 0.12, 0.63; P = 0.002). Proximity to alcohol outlets was mostly unrelated to risks for gun assault.

CONCLUSIONS

Individuals in areas with greater densities of bars and restaurants and beer stores appear to be at increased risk for non-gun assault at times when these outlets are likely to be patronized most heavily.

Tobacco outlet density, retailer cigarette sales without ID checks and enforcement of underage tobacco laws: associations with youths' cigarette smoking and beliefs

AIMS

To estimate the relationships of tobacco outlet density, cigarette sales without ID checks and local enforcement of underage tobacco laws with youth's life-time cigarette smoking, perceived availability of tobacco and perceived enforcement of underage tobacco laws and changes over time.

DESIGN

The study involved: (a) three annual telephone surveys, (b) two annual purchase surveys in 2000 tobacco outlets and (c) interviews with key informants from local law enforcement agencies. Analyses were multi-level models (city, individual, time).

SETTING

A sample of 50 mid-sized non-contiguous cities in California, USA.

PARTICIPANTS

A total of 1478 youths (aged 13-16 at wave 1, 52.2% male); 1061 participated in all waves.

MEASUREMENTS

Measures at the individual level included life-time cigarette smoking, perceived availability and perceived enforcement. City-level measures included tobacco outlet density, cigarette sales without ID checks and compliance checks.

FINDINGS

Outlet density was associated positively with life-time smoking [OR = 1.12, P < 0.01]. An interaction between outlet density and wave (OR = 0.96, P < 0.05) suggested that higher density was associated more closely with life-time smoking at the earlier waves when respondents were younger. Greater density was associated positively with perceived availability (β = 0.02, P < 0.05) and negatively with perceived enforcement (β = -0.02, P < 0.01). Sales rate without checking IDs was related to greater perceived availability (β = 0.01, P < 0.01) and less perceived enforcement (β = -0.01, P < 0.01). Enforcement of underage tobacco laws was related positively to perceived enforcement (β = 0.06, P < 0.05).

CONCLUSIONS

Higher tobacco outlet density may contribute to life-time smoking among youths. Density, sales without ID checks and enforcement levels may influence beliefs about access to cigarettes and enforcement of underage tobacco sales laws.

The role of tobacco outlet density in a smoking cessation intervention for urban youth

This study investigates the role of tobacco outlet density in a randomized controlled trial of a text messaging-based smoking cessation intervention conducted among a sample of 187 primarily African American youth in a midsize U.S. city. A moderated mediation model was used to test whether the indirect effect of residential tobacco outlet density on future smoking was mediated by the intention to smoke, and whether this indirect effect differed between adolescents who received the intervention and those who did not. Results indicated that tobacco outlet density is associated with intention to smoke, which predicts future smoking, and that the indirect effect of tobacco outlet density on future smoking is moderated by the intervention. Tobacco outlet density and the intervention can be viewed as competing forces on future smoking behavior, where higher tobacco outlet density acts to mitigate the sensitivity of an adolescent to the intervention's intended effect. Smoking cessation interventions applied to youth should consider tobacco outlet density as a contextual condition that can influence treatment outcomes.

The added value of accounting for activity space when examining the association between tobacco retailer availability and smoking among young adults

BACKGROUND

Despite a declining prevalence in many countries, smoking rates remain consistently high among young adults. Targeting contextual influences on smoking, such as the availability of tobacco retailers, is one promising avenue of intervention. Most studies have focused on residential or school neighbourhoods, without accounting for other settings where individuals spend time, that is, their activity space. We investigated the association between tobacco retailer availability in the residential neighbourhood and in the activity space, and smoking status.

METHODS

Cross-sectional baseline data from 1994 young adults (aged 18-25) participating in the Interdisciplinary Study of Inequalities in Smoking (Montreal, Canada, 2011-2012) were analysed. Residential and activity locations served to derive two measures of tobacco retailer availability: counts within 500 m buffers and proximity to the nearest retailer. Prevalence ratios for the association between each tobacco retailer measure and smoking status were estimated using log-binomial regression.

RESULTS

Participants encountering high numbers of tobacco retailers in their residential neighbourhood, and both medium and high retailer counts in their activity space, were more likely to smoke compared to those exposed to fewer retailers. While residential proximity was not associated with smoking, we found 36% and 42% higher smoking prevalence among participants conducting activities within medium and high proximity to tobacco retailers compared to those conducting activities further from such outlets.

CONCLUSIONS

This study adds to the sparse literature on contextual correlates of smoking among young adults, and illustrates the added value of considering individuals' activity space in contextual studies of smoking.