Brief report: Using global positioning system (GPS) enabled cell phones to examine adolescent travel patterns and time in proximity to alcohol outlets.

As adolescents gain freedom to explore new environments unsupervised, more time in proximity to alcohol outlets may increase risks for alcohol and marijuana use. This pilot study: 1) Describes variations in adolescents' proximity to outlets by time of day and day of the week, 2) Examines variations in outlet proximity by drinking and marijuana use status, and 3) Tests feasibility of obtaining real-time data to study adolescent proximity to outlets. U.S. adolescents (N = 18) aged 16-17 (50% female) carried GPS-enabled smartphones for one week with their locations tracked. The geographic areas where adolescents spend time, activity spaces, were created by connecting GPS points sequentially and adding spatial buffers around routes. Proximity to outlets was greater during after school and evening hours. Drinkers and marijuana users were in proximity to outlets 1½ to 2 times more than non-users. Findings provide information about where adolescents spend time and times of greatest risk, informing prevention efforts.

Tracking Adolescents With Global Positioning System-Enabled Cell Phones to Study Contextual Exposures and Alcohol and Marijuana Use: A Pilot Study.

PURPOSE: Measuring activity spaces, places adolescents spend time, provides information about relations between contextual exposures and risk behaviors. We studied whether contextual exposures in adolescents' activity spaces differ from contextual risks present in residential contexts and examined relationships between contextual exposures in activity spaces and alcohol/marijuana use. METHODS: Adolescents (N = 18) aged 16-17 years carried global positioning system (GPS)-enabled smartphones for 1 week, with locations tracked. Activity spaces were created by connecting global positioning system points sequentially and adding buffers. Contextual exposure data (e.g., alcohol outlets) were connected to routes. Adolescents completed texts regarding behaviors. RESULTS: Adolescent activity spaces intersected 24.3 census tracts and contained nine times more alcohol outlets than that of residential census tracts. Outlet exposure in activity spaces was related to drinking. Low-socioeconomic status exposure was related to marijuana use. CONCLUSIONS: Findings suggest substantial differences between activity spaces and residential contexts and suggest that activity spaces are relevant for adolescent risk behaviors.

The economic geography of medical cannabis dispensaries in California.

BACKGROUND: The introduction of laws that permit the use of cannabis for medical purposes has led to the emergence of a medical cannabis industry in some US states. This study assessed the spatial distribution of medical cannabis dispensaries according to estimated cannabis demand, socioeconomic indicators, alcohol outlets and other socio-demographic factors. METHODS: Telephone survey data from 5940 residents of 39 California cities were used to estimate social and demographic correlates of cannabis consumption. These individual-level estimates were then used to calculate aggregate cannabis demand (i.e. market potential) for 7538 census block groups. Locations of actively operating cannabis dispensaries were then related to the measure of demand and the socio-demographic characteristics of census block groups using multilevel Bayesian conditional autoregressive logit models. RESULTS: Cannabis dispensaries were located in block groups with greater cannabis demand, higher rates of poverty, alcohol outlets, and in areas just outside city boundaries. For the sampled block groups, a 10% increase in demand within a block group was associated with 2.4% greater likelihood of having a dispensary, and a 10% increase in the city-wide demand was associated with a 6.7% greater likelihood of having a dispensary. CONCLUSION: High demand for cannabis within individual block groups and within cities is related to the location of cannabis dispensaries at a block-group level. The relationship to low income, alcohol outlets and unincorporated areas indicates that dispensaries may open in areas that lack the resources to resist their establishment.

Assessing the Validity of On-Premise Alcohol License Data in Six Communities in California: Operating Characteristics and Outlet Densities.

This study evaluated State of California alcohol license records as a measure of businesses selling alcohol for consumption on premise. In 2008, researchers attempted to visit all 799 licensed restaurants, bars, and pubs in six medium-sized cities near San Francisco. Surveys collected detailed business characteristics for a subsample of 151 bars or restaurants that included a separate bar area. Results suggest inaccuracies of official records regarding license locations and types (bar/pub vs. restaurant). Analyses also indicate that establishment characteristics are related to local alcohol outlet densities. Study implications and limitations are discussed.

Testing a social ecological model of alcohol use: the California 50-city study.

BACKGROUND AND AIMS: Social ecological theories suggest that greater community alcohol availability and individual drinker characteristics should jointly affect drinking patterns and the use of drinking contexts. We assessed relationships of demographic and personality characteristics of individual drinkers and environmental characteristics at the city-level to measures of drinking patterns and use of drinking contexts. DESIGN: Multi-level statistical analyses of archival and survey data from 50 cities in California, USA. SETTINGS: An ecological sample of 50 geographically distinct cities with populations from 50 000 to 500 000 people. PARTICIPANTS: General population telephone survey of 8553 adults 18 years of age and older stratified by cities. MEASUREMENTS: Archival data on city-level alcohol outlet densities were combined with individual survey data identifying community conditions, individual demographic and psychosocial characteristics, frequencies of use of drinking contexts and drinking patterns. FINDINGS: Greater on-premise outlet densities were related to greater drinking frequencies (b = 2.9671, z = 4.688, P < 0.001) and volumes (b = 0.6274, z = 3.394, P < 0.001) and use of on-premises drinking places (bars, b = 0.3340, z = 2.645, P < 0.006 and restaurants, b = 0.1712, z = 2.770, P = 0.005). Individual demographic and personality characteristics were related to drinking and use of drinking contexts. For example, greater impulsivity was related to greater drinking frequencies (b = 0.2001, z = 2.088, P = 0.023) and logged quantities (b = 0.0151, z = 2.009, P = 0.026) and proportionately more drinking at bars (b = 0.0332, z = 2.016, P = 0.026) and parties (b = 0.1712, z = 2.770, P = 0.004). CONCLUSION: Community availability of alcohol and individual drinker characteristics appear to act jointly to affect drinking levels and use of drinking contexts. These effects may increase risks related to drinking in some contexts (e.g. bars) much more than others (e.g. at friends' or relatives' homes).

Exploring the Spread of Methamphetamine Problems within California, 1980 to 2006.

BACKGROUND: The introduction and spread of high potency methamphetamine has led to dramatic increases in drug-related problems in California. Prior research suggests that drug abuse rates are related to local demographic and economic characteristics, law enforcement activities, and sentencing practices. Methamphetamine abuse in particular has been shown to be reduced by laws regulating the raw materials needed for its production. This research models the regional effects of such laws on the spatio-temporal patterns of growth of methamphetamine-related problems across California from 1980 to 2006. METHODS: Amphetamine-related arrests and hospital discharges related to amphetamine abuse / dependence were assembled for California counties over the years 1980 through 2006. Varying-parameter Bayesian space-time models were used to relate the implementation of major laws controlling the distribution of methamphetamine precursors to observed patterns of arrests and discharges and to allow such associations to vary by location. The models used conditionally autoregressive (CAR) Bayesian spatial priors to allow spatial correlation in estimation of county-specific growth in these measures over three distinct time periods: before the 1989 law, between the 1989 and 1997 laws, and after the 1997 law. Growth of arrests and discharges were related to demographic and economic indicators to determine geographic areas more or less susceptible to the spread of methamphetamine problems. RESULTS: Although both problem measures increased during all three periods, each of the precursor laws was associated with short-term reductions in the growth of arrests and discharges. Growth was greatest in central California counties prior to 1989 and increased in coastal counties in later years. From 1980 to 1989 growth was highest for counties with low incomes and high proportions of white residents, while 1989-1997 growth was highest in counties with fewer whites and more Hispanics. Growth after 1997 was not significantly associated with county characteristics. CONCLUSION: This research demonstrates that the precursor laws did suppress the growth of methamphetamine related arrests and hospital discharges. It also demonstrates specific geographic patterns in the growth of methamphetamine arrests and abuse across California during this time. Early patterns of growth were related to economic and demographic characteristics, while later patterns were not. This suggests that some counties were uniquely susceptible to the early spread of the methamphetamine epidemic, although problems eventually grew dramatically in all California counties.

Spatial panel analyses of alcohol outlets and motor vehicle crashes in California: 1999-2008.

Although past research has linked alcohol outlet density to higher rates of drinking and many related social problems, there is conflicting evidence of density's association with traffic crashes. An abundance of local alcohol outlets simultaneously encourages drinking and reduces driving distances required to obtain alcohol, leading to an indeterminate expected impact on alcohol-involved crash risk. This study separately investigates the effects of outlet density on (1) the risk of injury crashes relative to population and (2) the likelihood that any given crash is alcohol-involved, as indicated by police reports and single-vehicle nighttime status of crashes. Alcohol outlet density effects are estimated using Bayesian misalignment Poisson analyses of all California ZIP codes over the years 1999-2008. These misalignment models allow panel analysis of ZIP-code data despite frequent redefinition of postal-code boundaries, while also controlling for overdispersion and the effects of spatial autocorrelation. Because models control for overall retail density, estimated alcohol-outlet associations represent the extra effect of retail establishments selling alcohol. The results indicate a number of statistically well-supported associations between retail density and crash behavior, but the implied effects on crash risks are relatively small. Alcohol-serving restaurants have a greater impact on overall crash risks than on the likelihood that those crashes involve alcohol, whereas bars primarily affect the odds that crashes are alcohol-involved. Off-premise outlet density is negatively associated with risks of both crashes and alcohol involvement, while the presence of a tribal casino in a ZIP code is linked to higher odds of police-reported drinking involvement. Alcohol outlets in a given area are found to influence crash risks both locally and in adjacent ZIP codes, and significant spatial autocorrelation also suggests important relationships across geographical units. These results suggest that each type of alcohol outlet can have differing impacts on risks of crashing as well as the alcohol involvement of those crashes.

Mapping the spread of methamphetamine abuse in California from 1995 to 2008.

OBJECTIVES: From 1983 to 2008, the incidence of methamphetamine abuse and dependence (MA) presenting at hospitals in California increased 13-fold. We assessed whether this growth could be characterized as a drug epidemic. METHODS: We geocoded MA discharges to residential zip codes from 1995 through 2008. We related discharges to population and environmental characteristics using Bayesian Poisson conditional autoregressive models, correcting for small area effects and spatial misalignment and enabling an assessment of contagion between areas. RESULTS: MA incidence increased exponentially in 3 phases interrupted by implementation of laws limiting access to methamphetamine precursors. MA growth from 1999 through 2008 was 17% per year. MA was greatest in areas with larger White or Hispanic low-income populations, small household sizes, and good connections to highway systems. Spatial misalignment was a source of bias in estimated effects. Spatial autocorrelation was substantial, accounting for approximately 80% of error variance in the model. CONCLUSIONS: From 1995 through 2008, MA exhibited signs of growth and spatial spread characteristic of drug epidemics, spreading most rapidly through low-income White and Hispanic populations living outside dense urban areas.

Assessing correlates of the growth and extent of methamphetamine abuse and dependence in California.

Using aggregate-level data, this study performed cross-sectional analyses on all 1,628 populated California zip code areas and longitudinal analyses on 581 consistently defined zip codes over six years (1995-2000), relating place and population characteristics of these areas to rates of hospital discharges for amphetamine dependence/abuse using linear spatial models. Analyzing the data in two ways, spatial time series cross-sections and spatial difference models, amphetamine dependence/abuse were greatest in rural areas with more young low-income whites, larger numbers of retail and alcohol outlets, and smaller numbers of restaurants. Growth rates of these problems were greater in areas with higher income and larger non-White and Hispanic populations. This suggests that there was some change in the penetration of the methamphetamine epidemic into different population groups during this time. Study implications and limitations are discussed.

Suicide and alcohol: do outlets play a role?

BACKGROUND: The purpose of this study was to determine whether the number of alcohol outlets in local and adjacent areas, in particular bars, was related over time to completed suicide and suicide attempts. There is evidence both from studies of individuals and time series aggregate studies, mostly at the national level, of substantial alcohol involvement in suicide, but no small-area, longitudinal studies have been carried out. The present study is the first that is both longitudinal and based on a large number of small spatial units, California zip codes, a level of resolution permitting analysis of the relationship between local alcohol access and suicide rates over time. METHOD: Longitudinal data were obtained from 581 consistently defined zip code areas over 6 years (1995-2000) using data from the California Index Locations Database, a geographic information system that contains both population and place information with spatial attributes for the entire state. Measures obtained from each zip code included population characteristics (e.g., median age) and place characteristics (e.g., numbers of retail and alcohol outlets) which were related in separate analyses to (i) suicide mortality and (ii) the number of hospitalizations for injuries caused by suicide attempts. The effect of place characteristics in zip code areas adjacent to each of the 581 local zip codes (spatial lags) was also assessed. Analysis methods were random effects models corrected for spatial autocorrelation. RESULTS: Completed suicide rates were higher in zip code areas with greater local and lagged bar densities; and higher in areas with greater local but not lagged off-premise outlet densities. Whereas completed suicide rates were lower among blacks and Hispanics, completed suicide rates were higher among low income, older whites living in less densely populated areas, that is, rural areas. Rates of suicide attempts were higher in zip code areas with greater local but not lagged bar densities, and higher among low income younger whites living in smaller households and in rural areas. Rates of attempted suicide were also higher among blacks. Completed suicide and suicide attempt rates were lower in zip code areas with greater local restaurant densities; there were no lagged effects for restaurants. CONCLUSIONS: Bar densities in particular appear related to suicide, meaning, because this is an aggregate-level spatial analysis, that suicides, both attempted and completed, occur at greater rates in rural community areas with greater bar densities. Because the suicide rate is highest in rural areas, this study suggests that although the number of completed and attempted suicides is no doubt greater in absolute numbers in urban areas, the suicide rate, both completed and attempted, is greater in rural areas, which draws attention, perhaps much needed, to the problems of rural America.

Does alcohol outlet density affect youth access to alcohol?

PURPOSE: To investigate how community alcohol outlet density may be associated with alcohol access among adolescents. METHODS: Data were collected through a three-wave panel study with youth aged 14-16 at baseline using computer-assisted telephone interviews. Study participants were recruited from 50 zip codes with varying alcohol outlet density and median household income in California. Data analyses were conducted using multilevel, linear growth models and data from 1028 youth (52% male, 51% white). RESULTS: After taking into account individual-level factors and zip code median household income, zip code alcohol outlet density was significantly and positively related to the initial levels of the likelihood and frequency of getting alcohol through various sources including commercial outlets, shoulder tapping, home or family members, and underage acquaintances. CONCLUSIONS: High levels of alcohol outlets in the community enable youth access to alcohol through commercial outlets, family, and social networks.

Alcohol outlets, youth drinking, and self-reported ease of access to alcohol: a constraints and opportunities approach.

BACKGROUND: Despite recent research examining youth access to alcohol, the extent to which relative ease of access to alcohol from various sources translates into the use of these sources is not known. METHODS: Patterns of adolescent alcohol access in California were studied using a hierarchical analysis of self-reported and archival measures. A survey of 30 youths age 14 to 16 in each of 50 zip codes selected to maximize variability in median household income and off-premise outlet densities was conducted. RESULTS: (1) Both actual use of and perceived ease of access to formal sources were positively associated with off-premise outlet density (a measure of formal access). (2) Actual use of informal sources was negatively associated with outlet densities. (3) Perceived and realized informal access were associated positively with deviance and negatively with conventionality. (4) Deviance was associated with increased perceived and realized access from both formal and social sources, whereas conventionality was only associated with realized and perceived informal access. CONCLUSIONS: Correlates of perceived and actual alcohol access differ somewhat, and the differences between informal and formal access (both perceived and actual) are many, creating a complex picture of the patterns of underage access to alcohol. Youth drinking is affected by opportunities and constraints. Specifically, as one form of access becomes constrained, youth appear to circumvent restrictions by relying on other modes of access. Thus interventions targeting formal alcohol access by youth may result in a shift to reliance on social sources. This complex problem requires a multi-faceted intervention approach.

Examining multi-level relationships between bars, hostility and aggression: social selection and social influence.

AIMS: This paper considers statistical relationships often observed between densities of bars and pubs and rates of violence as suggested by two general approaches: (i) social influence and (ii) social selection. METHODS: A stratified sample of 36 zip code areas in California was identified as having 'high', 'medium' and 'low' densities of bars and pubs. Aggregate US Census 2000 data were used to characterize population demographics of each zip code area. Telephone surveys were conducted assessing respondent demographics, drinking patterns, utilization of different places for drinking, self-report measures of hostility, norms for aggression and norms for alcohol-related aggression. Hierarchical linear models assessed the degree to which densities of bars and pubs were related to self-reports of hostility and norms for aggression, and if the individual measures of hostility and norms for aggression were related to choice of drinking venue. RESULTS: Respondents living in areas with greater densities of bars and pubs reported lower norms for aggression and greater norms for alcohol-related aggression. Greater peak drinking levels were related directly to greater levels of hostility and norms for both aggression and alcohol-related aggression. Self-reported hostility and norms for alcohol-related aggression were related directly to drinking at bars and pubs, parties and friends' homes. Aggressive norms were related to drinking at parties. CONCLUSIONS: Whether bars serve to concentrate aggressive people into selected environments, whether these environments serve to increase levels of aggression, or whether both these processes reinforce each other mutually is not known. However, our findings do indicate relationships between certain exogenous measures, including alcohol outlet densities and social-psychological characteristics associated with violence. Many of these measures are also associated with the social contexts in which people drink.

Exploring the spatial dynamics of alcohol outlets and Child Protective Services referrals, substantiations, and foster care entries.

Controlling for neighborhood demographic characteristics, this study examined the relationship of alcohol outlets with rates of Child Protective Services (CPS) referrals, substantiations, and foster care entries from 1998-2003 in 579 zip codes in California. Data for this panel study were analyzed using spatial random effects panel models. Zip codes with higher concentrations of off-premise alcohol outlets (e.g., convenience or liquor stores) and proportions of Black residents had higher rates of maltreatment. Higher average household size and median household income were generally related to lower child maltreatment rates. More specifically, the model derived estimates that an average decrease of one off-premise outlet per zip code would reduce total referrals to CPS in the 579 zip codes by 1,040 cases, substantiations by 180 cases, and foster care entries by 93 cases. Characteristics of adjacent zip codes also were related to maltreatment rates in local neighborhoods, indicating a spatial dynamic to this relationship. Reductions in number of alcohol outlets per zip code, particularly off-premise outlets, may result in lower rates of child maltreatment.

The Sacramento Neighborhood Alcohol Prevention Project: outcomes from a community prevention trial.

OBJECTIVE: This article reports the results of the Sacramento Neighborhood Alcohol Prevention Project (SNAPP). SNAPP set as its goal the reduction of alcohol access, drinking, and related problems in two low-income, predominantly ethnic minority neighborhoods, focusing on individuals between the ages 15 and 29, an age group identified with high rates of alcohol-involved problems. METHOD: Two neighborhoods in Sacramento were selected to be the intervention sites because they were economically and ethnically diverse and had high rates of crime and other drinking-related problems. The quasi-experimental design of the study took a "phased" approach to program implementation and statistical examination of outcome data. Outcome-related data were collected in the intervention sites as well as in the Sacramento community at large. Five project interventions included a mobilization component to support the overall project, a community awareness component, a responsible beverage-service component, an underage-access law enforcement component, and an intoxicated-patron law enforcement component. Archival data were collected to measure and evaluate study outcomes and to provide background and demographic information for the study. RESULTS: Overall, we found significant (p < .05) reductions in assaults as reported by police, aggregate emergency medical services (EMS) outcomes, EMS assaults, and EMS motor vehicle accidents. CONCLUSIONS: Results from the Sacramento Neighborhood Alcohol Prevention Project demonstrate the effectiveness of neighborhood-based interventions in the reduction of alcohol-related problems such as assaults, motor vehicle crashes, and sale of alcohol to minors.

The impact of outlet densities on alcohol-related crashes: a spatial panel approach.

BACKGROUND: A number of studies using cross-sectional data have demonstrated that the availability of alcohol, measured by the number and types of alcohol outlets, is directly related to numerous measures associated with drinking and driving. The current study contributes the first observation of relationships over time between alcohol outlet densities on one hand and both automobile crashes and related injuries on the other hand. METHOD: The study examined longitudinal data from 581 consistently defined zip code areas represented in the California Index Locations Database, a geographic information system that coordinates population and ecological data with spatial attributes for areas across the state. Six years of data were collected on features of local populations (e.g., demographics, household size) and places (e.g., retail markets) thought to be related to two measures of automobile crashes (hospital discharges related to car crash injuries geocoded to the zip code of patient residence, and police reports associated with car crashes geocoded to the zip code of crash location). Both crash measures were positively associated with two outlet types: bars, and off-premise outlets. Additionally, restaurants appear to provide a protective effect relative to the residence-based measure. Crash rates were also related to changes in population and place characteristics using random effects models with controls for spatial autocorrelation (nxt=3486 observations). Changes in population and place characteristics of adjacent (spatially lagged) areas were also considered. RESULTS: Over time, both local and lagged population and place characteristics were related to automobile crash-related measures. CONCLUSION: Controlling for cross-sectional differences between zip code areas, changes in numbers of licensed alcohol retail establishments, especially bars and off-premise outlets, affect rates of car crashes and related injuries.