Geospatial technology and the "exposome": new perspectives on addiction

Lifestyle differences between co-twins are associated with decreased similarity in their internal and external exposome profiles

Whether differences in lifestyle between co-twins are reflected in differences in their internal or external exposome profiles remains largely underexplored. We therefore investigated whether within-pair differences in lifestyle were associated with within-pair differences in exposome profiles across four domains: the external exposome, proteome, metabolome and epigenetic age acceleration (EAA). For each domain, we assessed the similarity of co-twin profiles using Gaussian similarities in up to 257 young adult same-sex twin pairs (54% monozygotic). We additionally tested whether similarity in one domain translated into greater similarity in another. Results suggest that a lower degree of similarity in co-twins' exposome profiles was associated with greater differences in their behavior and substance use. The strongest association was identified between excessive drinking behavior and the external exposome. Overall, our study demonstrates how social behavior and especially substance use are connected to the internal and external exposomes, while controlling for familial confounders.

A Qualitative Exploration of Attitudes Toward Global Positioning System Tracking and Ecological Momentary Assessment Among Individuals in Substance Use Treatment

BACKGROUND

The use of tracking technology in substance use research can uncover the role of contextual factors, such as social networks and environmental cues, in triggering cravings and precipitating return to use. Few studies have explored the opinions of individuals in substance use treatment related to tracking technology.

METHODS

We conducted 30 semi-structured interviews with individuals in substance use treatment facilities in Connecticut and Georgia. Interviews were not limited to individuals with any specific substance use disorder. Interviewers described a hypothetical study involving ecological momentary assessment and global positioning system tracking to examine place-based predictors of substance use. Participants were invited to share reactions to this description. We used thematic analysis to identify themes in participant perceptions of this hypothetical research study.

RESULTS

Most participants shared positive opinions about study participation and expressed little to no concern about the tracking components. Participant concerns focused on the security of their information and the potential burden of responding to study questions. Participants largely understood the importance of study participation for promoting greater understanding of substance use and identified potential therapeutic effects of study participation on their own recovery.

CONCLUSIONS

Individuals in substance use treatment expressed little concern with research studies or interventions incorporating mobile-tracking elements. Future studies should explore the responsible use of tracking elements in recovery support interventions.

Lifestyle differences between co-twins are associated with decreased similarity in their internal and external exposome profiles

Whether differences in lifestyle between co-twins are reflected in differences in their internal or external exposome profiles remains largely underexplored. We therefore investigated whether within-pair differences in lifestyle were associated with within-pair differences in exposome profiles across four domains: the external exposome, proteome, metabolome and epigenetic age acceleration (EAA). For each domain, we assessed the similarity of co-twin profiles using Gaussian similarities in up to 257 young adult same-sex twin pairs (54% monozygotic). We additionally tested whether similarity in one domain translated into greater similarity in another. Results suggest that a lower degree of similarity in co-twins' exposome profiles was associated with greater differences in their behavior and substance use. The strongest association was identified between excessive drinking behavior and the external exposome. Overall, our study demonstrates how social behavior and especially substance use are connected to the internal and external exposomes, while controlling for familial confounders.

An external exposome-wide association study of opioid use disorder diagnosed during pregnancy in Florida

The prevalence of opioid use disorder (OUD) during pregnancy has quadrupled in recent years and widely varies geographically in the US. However, few studies have examined which environmental factors are associated with OUD during pregnancy. We conducted an external exposome-wide association study (ExWAS) to investigate the associations between external environmental factors and OUD diagnosed during pregnancy. Data were obtained from a unique, statewide database in Florida comprising linked individual-level birth and electronic health records. A total of 255,228 pregnancies with conception dates between 2012 and 2016 were included. We examined 82 exposome measures characterizing seven aspects of the built and social environment and spatiotemporally linked them to each individual record. A two-phase procedure was utilized for the external ExWAS. In Phase 1, we randomly divided the data into a discovery set (50 %) and a replication set (50 %). Associations between exposome measures (normalized and standardized) and OUD initially diagnosed during pregnancy were examined using logistic regression. A total of 15 variables were significant in both the discovery and replication sets. In Phase 2, multivariable logistic regression was used to fit all variables selected from Phase 1. Measures of walkability (the national walkability index, OR: 1.23, 95 % CI: 1.17, 1.29), vacant land (the percent vacant land for 36 months or longer, OR: 1.06, 95 % CI: 1.00, 1.12) and food access (the percentage of low food access population that are seniors at 1/2 mile, OR: 1.47, 95 % CI: 1.38, 1.57) were each associated with diagnosis of OUD during pregnancy. This is the first external ExWAS of OUD during pregnancy, and the results suggest that low food access, high walkability, and high vacant land in under-resourced neighborhoods are associated with diagnosis of OUD during pregnancy. These findings could help develop complementary tools for universal screening for substance use and provide direction for future studies.

The co-occurrence of smoking and alcohol use disorder in a hospital-based population: Applying a multimorbidity framework using geographic information system methods

Tobacco and alcohol use are leading causes of premature mortality in the US and concurrent use is associated with even greater health risks. A cross-sectional study of 20,310 patients admitted to a Mid-Atlantic acute health care system between July 1, 2018 and June 30, 2019 were categorized according to smoking and alcohol use disorder (AUD) status. Of the total admissions, 1464 (7.2%) were current smokers with an AUD. These patients were younger (52.4 vs. 63.9), more likely to be male (64.1% vs. 38.0%) and covered by Medicaid (46.9% vs. 11.6%), and resided in proximity to higher counts of tobacco (10.3 vs. 4.72) and alcohol (2.24 vs. 1.14) retailers than never smokers without an AUD. Clinically, these patients had higher rates of other substance use disorders (60.4% vs. 6.1%), depression (64.6% vs. 34.8%), HIV/AIDS (3.3% vs. 0.6%), and liver disease (40.7% vs. 13.2%) than never smokers without an AUD. Patients who concurrently smoke and have an AUD face unique and serious health risks. A multimorbidity framework can guide clinical and community-based interventions for individuals with concurrent psychiatric and chronic medical conditions, complex social needs, and adverse environmental exposures.

Interstitial Lung Diseases and Air Pollution: Narrative Review of Literature

Air pollution has been associated with respiratory diseases such as chronic obstructive pulmonary disease (COPD) and lung malignancies. The aim of this narrative review is to analyze the current data on the possible association between air pollution and interstitial lung disease (ILD). There are multiple studies showing the association of ILD with air pollution but the mechanism remains unclear. Although some of the environmental factors have been associated with idiopathic pulmonary fibrosis (IPF), hypersensitivity pneumonitis (HP), and pneumoconiosis, data about other ILDs are scarce and not well known. Air pollution as an etiology for ILD may act in multiple ways, leading to disease pathogenesis or exacerbation of underlying ILD. Clinical implications of this association are manifold; limiting the exposure to poor-quality air could possibly reduce the fall in lung functions and the risk of acute exacerbations of the underlying ILD.

Air pollution is a major problem worldwide. Pollutants are vented out in the ambient air by sources like vehicular fume exhaust, factory pollution, combustion by burning of biomass fuels, and indoor pollution. The probable constituents responsible for respiratory diseases are particulate matter 2.5 and 10, nitrogen dioxide (NO₂), and ozone present in polluted air. The role of these pollutants in pathogenesis of interstitial lung disease (ILD) is complex. The probable pathways include: oxidative stress, inflammation, and telomere shortening. ILD is a heterogeneous group of diseases, and the effect of pollution on various types is also varied. Air pollution has been associated with poor lung function and exacerbations in idiopathic pulmonary fibrosis (IPF), increased prevalence of hypersensitivity pneumonitis (HP), and presence of pulmonary fibrosis in healthy adults and children. The incidence rate of IPF has also been associated with pollutant levels such as NO₂. Thus, patients with ILD should be cautious during bad-quality air days and they are advised to avoid outdoor activities and use facemasks during this period.

Within- and between-person associations of neighborhood poverty with alcohol use and consequences: A monthly study of young adults

BACKGROUND

Studies have shown associations between neighborhood disadvantage and alcohol misuse among adults. Less is known about the role of neighborhood context in young adults (YAs), who engage in more disordered forms of alcohol use compared to other age groups. Using data collected monthly, this study examined whether YAs reported more alcohol use and consequences when they were living in neighborhoods with greater concentration of poverty.

METHOD

This study used data from 746 participants aged 18-23 years living in the Seattle, WA, region. Surveys were administered each month for 24 consecutive months. Measures included typical number of drinks per week and past month count of alcohol-related consequences. Residential addresses at each month were geocoded and linked to census-tract level percentage of households living at or below poverty threshold. Multilevel over-dispersed Poisson models were used to estimate associations between standardized monthly deviations in tract-level poverty from one's average and alcohol outcomes.

RESULTS

Across 14,247 monthly observations, the mean number of typical drinks per week was 4.8 (SD = 7.4) and the mean number of alcohol consequences was 2.1 (SD = 3.5). On months when they were living in neighborhoods with higher levels of poverty than their average, participants reported significantly higher levels of alcohol consequences (Count Ratio = 1.05; p = .045).

CONCLUSION

YAs may engage in more problematic forms of drinking when they reside in neighborhoods with higher levels of disadvantage. During a time of frequent residential changes, YAs moving to more disadvantaged neighborhoods may benefit from additional supports.

Privacy, Confidentiality, and Safety Considerations for Conducting Geographic Momentary Assessment Studies Among Persons Who Use Drugs and Men Who Have Sex with Men

Geographic momentary assessments (GMA) collect real-time behavioral data in one's natural environment using a smartphone and could potentially increase the ecological validity of behavioral data. Several studies have evaluated the feasibility and acceptability of GMA among persons who use drugs (PWUD) and men who have sex with men (MSM), but fewer have discussed privacy, confidentiality, and safety concerns, particularly when illegal or stigmatized behavioral data were collected. This study explores perceptions regarding privacy, confidentiality, and safety of GMA research among PWUD and MSM recruited in three different settings (rural Appalachia, a mid-sized city in the South, and a mid-Atlantic city). Between November 2014 and April 2017, we recruited 35 PWUD from rural Appalachian Kentucky (N = 20) and Baltimore, Maryland (N = 15) and 20 MSM from Lexington, Kentucky to complete semi-structured qualitative interviews. Through thematic analyses, we identified and compared privacy, confidentiality, and safety concerns by demographic characteristics, risk behaviors, and setting. Privacy, confidentiality, and safety concerns varied by setting, age, smartphone ownership, use of illegal drugs, and history of drug-related arrests. Among those who used drugs, participants reported concerns with being tracked and burden associated with carrying and safeguarding study phones and responding to survey prompts. Privacy and confidentiality concerns were noted in each setting, but tracking concerns were greatest among Baltimore participants and led many to feel that they (or others) would be unwilling to participate or comply with study procedures. While locations considered to be sensitive varied by setting, participants in all settings said they would take measures to prevent sensitive information from being collected (i.e., intentionally disable devices, leave phones at home, alter response times). Privacy, confidentiality, and safety concerns may limit the accuracy of risk location information, study compliance, and participation. As concerns were often greatest among those engaging in illegal behaviors and with the highest risk behaviors, selection bias and non-response bias could negatively influence the representativeness and validity of study findings.

Advancing Treatment of Depression and Other Mood Disorders Through Innovative Models of Telepsychiatry

Rapid changes in health care technology are advancing mental health care. Telepsychiatry, in the form of live interactive videoconferencing, has demonstrated its ability to improve access to high-quality mental health care, specifically in the treatment of patients with depression and mood disorders. This article reviews the advances in telepsychiatry in the treatment of depression and mood disorders. Telepsychiatry is significantly reconfiguring the structures and models of psychiatric care delivery. Such changes include direct-to-home services, blending telepsychiatry with other technologies, and using a team-based care approach. This article also examines the evolving and innovative models of care, synthesizes literature and lessons learned about telehealth, and considers current and future pragmatic implications for the treatment of depression and mood disorders in various clinical settings. Telepsychiatry has an important and expanding role in addressing the individual and societal psychiatric burdens of depression and mood disorders.

Geographic Imputation of Missing Activity Space Data from Ecological Momentary Assessment (EMA) GPS Positions

This research presents a pilot study to develop and compare methods of geographic imputation for estimating the location of missing activity space data collected using geographic ecological momentary assessment (GEMA). As a demonstration, we use data from a previously published analysis of the effect of neighborhood disadvantage, captured at the U.S. Census Bureau tract level, on momentary psychological stress among a sample of 137 urban adolescents. We investigate the impact of listwise deletion on model results and test two geographic imputation techniques adapted for activity space data from hot deck and centroid imputation approaches. Our results indicate that listwise deletion can bias estimates of place effects on health, and that these impacts are mitigated by the use of geographic imputation, particularly regarding inflation of the standard errors. These geographic imputation techniques may be extended in future research by incorporating approaches from the non-spatial imputation literature as well as from conventional geographic imputation and spatial interpolation research that focus on non-activity space data.

Geographic Information Science and the Analysis of Place and Health

The representation of place is a key theoretical advancement that Geographic Information Science can offer to improve the understanding of environmental determinants of health, but developing robust computational representations of place requires a substantial departure from conventional notions of geographic representation in Geographic Information Systems (GIS). Unlike conventional GIS representations based on either objects or locations, we suggest place representation should incorporate dynamic subjective, experiential, and relational aspects of place, as the influence of place on health behavior concerns not only the features that can be objectively observed at a particular location but also the environmental perceptions of the individual, as molded by biological, social, and experiential characteristics. In addition, assessments of environmental exposures on health outcomes should focus on individuals' time-activity patterns and microenvironment profiles, which form a potentially unique personalized exposure environment for each individual. Addressing these representational challenges via collaborative research has the potential to advance both Geographic Information Science and health research.

The spatial accuracy of geographic ecological momentary assessment (GEMA): Error and bias due to subject and environmental characteristics

BACKGROUND

Geographic ecological momentary assessment (GEMA) combines ecological momentary assessment (EMA) with global positioning systems (GPS) and geographic information systems (GIS). This study evaluates the spatial accuracy of GEMA location data and bias due to subject and environmental data characteristics.

METHODS

Using data for 72 subjects enrolled in a study of urban adolescent substance use, we compared the GPS-based location of EMA responses in which the subject indicated they were at home to the geocoded home address. We calculated the percentage of EMA locations within a sixteenth, eighth, quarter, and half miles from the home, and the percentage within the same tract and block group as the home. We investigated if the accuracy measures were associated with subject demographics, substance use, and emotional dysregulation, as well as environmental characteristics of the home neighborhood.

RESULTS

Half of all subjects had more than 88% of their EMA locations within a half mile, 72% within a quarter mile, 55% within an eighth mile, 50% within a sixteenth of a mile, 83% in the correct tract, and 71% in the correct block group. There were no significant associations with subject or environmental characteristics.

CONCLUSIONS

Results support the use of GEMA for analyzing subjects' exposures to urban environments. Researchers should be aware of the issue of spatial accuracy inherent in GEMA, and interpret results accordingly. Understanding spatial accuracy is particularly relevant for the development of 'ecological momentary interventions' (EMI), which may depend on accurate location information, though issues of privacy protection remain a concern.

How Sensors Might Help Define the External Exposome

The advent of the exposome concept, the advancement of mobile technology, sensors, and the “internet of things” bring exciting opportunities to exposure science. Smartphone apps, wireless devices, the downsizing of monitoring technologies, along with lower costs for such equipment makes it possible for various aspects of exposure to be measured more easily and frequently. We discuss possibilities and lay out several criteria for using smart technologies for external exposome studies. Smart technologies are evolving quickly, and while they provide great promise for advancing exposure science, many are still in developmental stages and their use in epidemiology and risk studies must be carefully considered. The most useable technologies for exposure studies at this time relate to gathering exposure-factor data, such as location and activities. Development of some environmental sensors (e.g., for some air pollutants, noise, UV) is moving towards making the use of these more reliable and accessible to research studies. The possibility of accessing such an unprecedented amount of personal data also comes with various limitations and challenges, which are discussed. The advantage of improving the collection of long term exposure factor data is that this can be combined with more “traditional” measurement data to model exposures to numerous environmental factors.

Geospatial Approaches to Cancer Control and Population Sciences

Cancer incidence and mortality display strong geographic patterns worldwide and in the United States (1, 2). The environment where individuals live, work, and play is increasingly being recognized as important across the cancer control continuum, including the risk of cancer development, detection, diagnosis, treatment, mortality, and survivorship (3-5). At the same time, emergent technological capacity in geographic information systems (GIS) and mapping, along with increasing sophistication in applied spatial methods, has resulted in a growing research community developing and applying geospatial approaches in health research (5). Through collaborative, transdisciplinary efforts, and continued data collection efforts, there is great potential to apply these emerging geospatial approaches to various aspects of cancer prevention and control to inform etiology and target interventions and implementation of efficacious risk-reducing strategies. Cancer Epidemiol Biomarkers Prev; 26(4); 472-5. ©2017 AACRSee all the articles in this CEBP Focus section, "Geospatial Approaches to Cancer Control and Population Sciences."

Ethical considerations and potential threats to validity for three methods commonly used to collect geographic information in studies among people who use drugs

BACKGROUND

Analyses with geographic data can be used to identify "hot spots" and "health service deserts", examine associations between proximity to services and their use, and link contextual factors with individual-level data to better understand how environmental factors influence behaviors. Technological advancements in methods for collecting this information can improve the accuracy of contextually-relevant information; however, they have outpaced the development of ethical standards and guidance, particularly for research involving populations engaging in illicit/stigmatized behaviors. Thematic analysis identified ethical considerations for collecting geographic data using different methods and the extent to which these concerns could influence study compliance and data validity.

METHODS

In-depth interviews with 15 Baltimore residents (6 recruited via flyers and 9 via peer-referral) reporting recent drug use explored comfort with and ethics of three methods for collecting geographic information: (1) surveys collecting self-reported addresses/cross-streets, (2) surveys using web-based maps to find/confirm locations, and (3) geographical momentary assessments (GMA), which collect spatiotemporally referenced behavioral data.

RESULTS

Survey methods for collecting geographic data (i.e., addresses/cross-streets and web-based maps) were generally acceptable; however, participants raised confidentiality concerns regarding exact addresses for illicit/stigmatized behaviors. Concerns specific to GMA included burden of carrying/safeguarding phones and responding to survey prompts, confidentiality, discomfort with being tracked, and noncompliance with study procedures. Overall, many felt that confidentiality concerns could influence the accuracy of location information collected for sensitive behaviors and study compliance.

CONCLUSIONS

Concerns raised by participants could result in differential study participation and/or study compliance and questionable accuracy/validity of location data for sensitive behaviors.

Does substance use moderate the association of neighborhood disadvantage with perceived stress and safety in the activity spaces of urban youth?

BACKGROUND

This study investigates the association of activity space-based exposure to neighborhood disadvantage with momentary perceived stress and safety, and the moderation of substance use on those associations, among a sample of 139 urban, primarily African American, adolescents.

METHOD

Geospatial technologies are integrated with Ecological Momentary Assessment (EMA) to capture exposure to neighborhood disadvantage and perceived stress and safety in the activity space. A relative neighborhood disadvantage measure for each subject is calculated by conditioning the neighborhood disadvantage observed at the EMA location on that of the home neighborhood. Generalized estimating equations (GEE) are used to model the effect of relative neighborhood disadvantage on momentary perceived stress and safety, and the extent to which substance use moderates those associations.

RESULTS

Relative neighborhood disadvantage is significantly associated with higher perceived stress, lower perceived safety, and greater substance use involvement. The association of relative neighborhood disadvantage with stress is significantly stronger among those with greater substance use involvement.

CONCLUSION

This research highlights the value of integrating geospatial technologies with EMA and developing personalized measures of environmental exposure for investigating neighborhood effects on substance use, and suggests substance use intervention strategies aimed at neighborhood conditions. Future research should seek to disentangle the causal pathways of influence and selection that relate neighborhood environment, stress, and substance use, while also accounting for the role of gender and family and peer social contexts.

Emerging technologies to measure neighborhood conditions in public health: implications for interventions and next steps

Adverse neighborhood conditions play an important role beyond individual characteristics. There is increasing interest in identifying specific characteristics of the social and built environments adversely affecting health outcomes. Most research has assessed aspects of such exposures via self-reported instruments or census data. Potential threats in the local environment may be subject to short-term changes that can only be measured with more nimble technology. The advent of new technologies may offer new opportunities to obtain geospatial data about neighborhoods that may circumvent the limitations of traditional data sources. This overview describes the utility, validity and reliability of selected emerging technologies to measure neighborhood conditions for public health applications. It also describes next steps for future research and opportunities for interventions. The paper presents an overview of the literature on measurement of the built and social environment in public health (Google Street View, webcams, crowdsourcing, remote sensing, social media, unmanned aerial vehicles, and lifespace) and location-based interventions. Emerging technologies such as Google Street View, social media, drones, webcams, and crowdsourcing may serve as effective and inexpensive tools to measure the ever-changing environment. Georeferenced social media responses may help identify where to target intervention activities, but also to passively evaluate their effectiveness. Future studies should measure exposure across key time points during the life-course as part of the exposome paradigm and integrate various types of data sources to measure environmental contexts. By harnessing these technologies, public health research can not only monitor populations and the environment, but intervene using novel strategies to improve the public health.

Risky Substance Use Environments and Addiction: A New Frontier for Environmental Justice Research

Substance use disorders are widely recognized as one of the most pressing global public health problems, and recent research indicates that environmental factors, including access and exposure to substances of abuse, neighborhood disadvantage and disorder, and environmental barriers to treatment, influence substance use behaviors. Racial and socioeconomic inequities in the factors that create risky substance use environments may engender disparities in rates of substance use disorders and treatment outcomes. Environmental justice researchers, with substantial experience in addressing racial and ethnic inequities in environmental risk from technological and other hazards, should consider similar inequities in risky substance use environments as an environmental justice issue. Research should aim at illustrating where, why, and how such inequities in risky substance use environments occur, the implications of such inequities for disparities in substance use disorders and treatment outcomes, and the implications for tobacco, alcohol, and drug policies and prevention and treatment programs.

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.

Socioeconomic and Geographic Inequalities of Internet Addiction in Korean Adolescents

The aim of this study was to evaluate the social economic and geographic influences on Internet addiction in Korean youth using the Korean Youth Risk Behavior Web-Based Survey. Middle and high school students (n=73,238) were randomly selected from the respondents to a web-based survey using two-stage stratified complex sampling. A Geographical Information System was used to generate a Korean map of the level of Internet addiction for each province and complex sampling lower case logistic regression was used to investigate the relationship between social economic status (SES) and Internet addiction. Gyeonggi-do and Gyeongsang-namdo provinces have a higher total scores of Internet addiction. There were associations between Internet addiction and low SES (OR=1.504, 95% CI 1.156-1.956, p<0.01). There may need to be at multilevel approach which recognizes the different levels of need in provinces as well as trying to understand why the differences arise at an individual level.

Air pollution exposure: a novel environmental risk factor for interstitial lung disease?

Air pollution exposure is a well-established risk factor for several adverse respiratory outcomes, including airways diseases and lung cancer. Few studies have investigated the relationship between air pollution and interstitial lung disease (ILD) despite many forms of ILD arising from environmental exposures. There are potential mechanisms by which air pollution could cause, exacerbate, or accelerate the progression of certain forms of ILD via pulmonary and systemic inflammation as well as oxidative stress. This article will review the current epidemiologic and translational data supporting the plausibility of this relationship and propose a new conceptual framework for characterizing novel environmental risk factors for these forms of lung disease.

Real-time tracking of neighborhood surroundings and mood in urban drug misusers: application of a new method to study behavior in its geographical context

BACKGROUND

Maladaptive behaviors may be more fully understood and efficiently prevented by ambulatory tools that assess people's ongoing experience in the context of their environment.

METHODS

To demonstrate new field-deployable methods for assessing mood and behavior as a function of neighborhood surroundings (geographical momentary assessment; GMA), we collected time-stamped GPS data and ecological momentary assessment (EMA) ratings of mood, stress, and drug craving over 16 weeks at randomly prompted times during the waking hours of opioid-dependent polydrug users receiving methadone maintenance. Locations of EMA entries and participants' travel tracks calculated for the 12 before each EMA entry were mapped. Associations between subjective ratings and objective environmental ratings were evaluated at the whole neighborhood and 12-h track levels.

RESULTS

Participants (N=27) were compliant with GMA data collection; 3711 randomly prompted EMA entries were matched to specific locations. At the neighborhood level, physical disorder was negatively correlated with negative mood, stress, and heroin and cocaine craving (ps<.0001-.0335); drug activity was negatively correlated with stress, heroin and cocaine craving (ps .0009-.0134). Similar relationships were found for the environments around respondents' tracks in the 12h preceding EMA entries.

CONCLUSIONS

The results support the feasibility of GMA. The relationships between neighborhood characteristics and participants' reports were counterintuitive and counter-hypothesized, and challenge some assumptions about how ostensibly stressful environments are associated with lived experience and how such environments ultimately impair health. GMA methodology may have applications for development of individual- or neighborhood-level interventions.