Identifying the Population Sources of Alcohol Impaired Driving: An Assessment of Context Specific Drinking Risks.

OBJECTIVE: High-risk drinkers who drink in high-risk contexts like bars are recognized as a primary source of alcohol-impaired drivers and motor vehicle crashes within communities. We assess the contributions of drinking in other contexts to these outcomes. METHOD: Self-report survey data from 8,553 adults in 50 California cities were used to estimate rates of driving after drinking (DAD; driving within 4 hours of drinking any alcohol) and a measure of alcohol-impaired driving (AID; driving when having had "too much" to safely drive home) associated with drinking in bars, homes, restaurants, parties, and other contexts. RESULTS: Frequent drinking (b = .0588, z = 2.17, p = .030) and drinking outside the home, χ2(4) = 74.46, p < .001, at bars (b = .1418, z = 1.97, p = .049), and at restaurants (b = .2694, z = 5.60, p < .001) were related to greater DAD; lower risks were associated with drinking at home (b = -.0607, z = -2.16, p = .031). AID frequency was directly proportional to DAD (b = .0863, z = 8.43, p < .001) with no differences observed across contexts. Within a community of 100,000 persons over 6 months, 879 AID events were attributed to drinking at 102 restaurants and 726 AID events to drinking at 15 bars. CONCLUSIONS: Drinking at bars and restaurants contributes about equally to DAD and AID, with AID events concentrated in small populations that frequent relatively few bars and broadly distributed across large populations that frequent many restaurants. High frequencies of drinking at home were also associated with surprisingly large numbers of DAD and AID events. Observed differences between individual and community risks for DAD and AID must be addressed in place-based community prevention programs.

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).

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.

A dose-response perspective on college drinking and related problems.

AIMS: In order to examine the degree to which heavy drinking contributes to risks for problems among college drinkers this paper develops and tests a dose-response model of alcohol use that relates frequencies of drinking specific quantities of alcohol to the incidence of drinking problems. METHODS: A mathematical model was developed that enabled estimation of dose-response relationships between drinking quantities and drinking problems using self-report data from 8698 college drinkers across 14 campuses in California, USA. The model assumes that drinking risks are a direct monotone function of the amount consumed per day and additive across drinking days. Drinking problems accumulate across drinking occasions and are the basis for cumulative reports of drinking problems reported by college drinkers. RESULTS: Statistical analyses using the model showed that drinking problems were related to every drinking level, but increased fivefold at three drinks and more gradually thereafter. Problems were associated most strongly with occasions on which three drinks were consumed, and more than half of all reported problems were related to occasions on which four or fewer drinks were consumed. There were some important differences in dose-responsiveness between men and women and between different groups of 'light', 'moderate' and 'heavier' drinkers. CONCLUSION: Many problems among college students are associated with drinking relatively small amounts of alcohol (two to four drinks). Programs to reduce college drinking problems should emphasize risks associated with low drinking levels.

Ecological associations of alcohol outlets with underage and young adult injuries.

OBJECTIVE: This paper argues that associations between rates of 3 specific problems related to alcohol (i.e., accidents, traffic crashes, and assaults) should be differentially related to densities of alcohol outlets among underage youth and young adults based upon age-related patterns of alcohol outlet use. METHODS: Zip code-level population models assessed local and distal effects of alcohol outlets upon rates of hospital discharges for these outcomes. RESULTS: Densities of off-premise alcohol outlets were significantly related to injuries from accidents, assaults, and traffic crashes for both underage youth and young adults. Densities of bars were associated with more assaults and densities of restaurants were associated with more traffic crash injuries for young adults. CONCLUSIONS: The distribution of alcohol-related injuries relative to alcohol outlets reflect patterns of alcohol outlet use.

An ecological assessment of the population and environmental correlates of childhood accident, assault, and child abuse injuries.

BACKGROUND: This study examines the relationships of population and environmental characteristics to hospital discharges for childhood accident, assault, and child abuse injuries among youth from 0 to 17 years of age. METHODS: The analysis uses aggregate data on populations and environments in 1,646 California zip code areas that were collected for the year 2000. Zero inflated negative binomial models were used to assess ecological relationships between these characteristics and numbers of hospital discharges for childhood injuries from accidents and assaults; negative binomial models were used to assess these relationships for injuries related to child abuse. RESULTS: A number of different characteristics were related to the different injury outcomes. Childhood accident injuries were related to measures female headed households, adult to child ratio, and nonalcohol retail establishments (e.g., numbers of gas stations). Assault injuries were related to measures of poverty and vacant housing. All 3 outcomes were directly related to percent of female-headed households, percent African American residents, and density of off-premise alcohol outlets. CONCLUSIONS: The results demonstrate that both population and environmental characteristics are significantly correlated with rates of childhood injuries. These results suggest that some environmental characteristics, in particular the presence of many off-premise alcohol outlets in neighborhoods, may reduce the overall level of guardianship of children's activities in zip code areas, resulting in harm to their children.

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.

Joint impacts of minimum legal drinking age and beer taxes on US youth traffic fatalities, 1975 to 2001.

BACKGROUND: There is a considerable body of prior research indicating that a number of public policies that limit alcohol availability affect youth traffic fatalities. These limitations can be economic (e.g., beverage taxation), physical (e.g., numbers or operating hours of alcohol outlets), or demographic (e.g., minimum legal drinking age). The estimated impacts of these policies differ widely across studies. A full-price theoretical approach suggests that people weigh the benefits of drinking against the sum of all the associated costs, including the price of the beverages themselves plus the difficulty of obtaining them and any additional risks of injury or punishment related to their use. This study tested one prediction of this model, namely that the impact from changing one availability-related cost depends on the level of other components of full cost. METHODS: The current analyses concentrate on 2 forms of limitations on availability that have been shown to affect youth traffic fatalities: minimum legal drinking age (MLDA) laws and beer taxes. The interdependence between the impacts of MLDA and taxes is investigated using a panel of 48 US states over the period 1975 to 2001. All age-group-specific models control for numerous other variables previously shown to affect vehicle fatalities, as well as fixed effects to account for unexplained crosssectional and time-series variation. RESULTS: The analyses showed that raising either MLDA or beer taxes in isolation led to fewer youth traffic fatalities. As expected, a given change in MLDA causes a larger proportional change in fatalities when beer taxes are low than when they are high. CONCLUSIONS: These findings suggest that a community's expected benefit from a proposed limitation on alcohol availability depends on its current regulatory environment. Specifically, communities with relatively strong existing policies might expect smaller impacts than suggested by prior research, while places with weak current regulations might expect larger benefits from the same policy initiative.

Understanding the ecology of child maltreatment: a review of the literature and directions for future research.

Studies examining neighborhood characteristics in relation to social problems, including child maltreatment, have proliferated in the past 25 years. This article reviews the current state of knowledge of ecological studies of child maltreatment. Taken as a whole, these 18 studies document a stable ecological relationship among neighborhood impoverishment, housing stress, and rates of child maltreatment, as well as some evidence that unemployment, child care burden, and alcohol availability may contribute to child abuse and neglect. The authors include a discussion of methodological difficulties in conducting research at the neighborhood level and present a set of recommendations for future research that emphasizes movement from a simple examination of neighborhood-level characteristics toward a theoretically driven explication of processes and mechanisms supported by appropriate multilevel modeling techniques. The final goal of such efforts would be to enable practitioners to develop evidence-based neighborhood interventions that would prevent and reduce child abuse and neglect.

Ecological models of alcohol outlets and violent assaults: crime potentials and geospatial analysis.

AIMS: Empirical tests of relationships between alcohol outlets and violence are generally conducted with statistical controls for correlates related to characteristics of people and the places in which they live. Crime potentials theory asserts that certain subpopulations are disposed to participate in criminal activities (population potentials) and certain neighborhoods are more likely to be places where crimes occur (place potentials). The current study assesses the degree to which measures of the different geographic distributions of these potentials contribute to violent crime. DESIGN: Cross-sectional data on hospital discharges for violent assaults were obtained for residents of 1637 zip code areas in California. Assault rates were related to measures of population and place characteristics using spatial statistical models corrected for spatial autocorrelated error. FINDINGS: Rates of assault were related to population and place characteristics within zip code areas, and with characteristics of populations living in adjacent zip code areas. Assault rates were greater in densely populated, poor minority urban areas with greater residential instability. Assault rates were also greater in zip code areas adjacent to densely populated urban areas. Assault rates were related significantly to local densities of off-premise alcohol retail establishments, not bars. However, densities of bars moderated substantially effects related to local population characteristics. Bars were related significantly to violence in unstable poor minority areas and in rural middle-income areas of the state. CONCLUSION: Population and place characteristics are associated with rates of violence across spatial areas. Alcohol outlets directly affect and moderate potentials for violence associated with socio-demographic groups.

An exploratory study examining the spatial dynamics of illicit drug availability and rates of drug use.

This study examines the spatial relationship between drug availability and rates of drug use in neighborhood areas. Responses from 16,083 individuals were analyzed at the zip code level (n = 158) and analyses were conducted separately for youth and adults using spatial regression techniques. The dependent variable is the percentage of respondents using drugs in the past year. Neighborhood drug availability (the major independent variable) was measured by the percentage of non-drug users who had been approached to purchase drugs. Data were obtained as part of the Fighting Back community evaluation. For youth (aged 12 to 18), drug sales in adjacent and surrounding areas were positively associated with self-reported drug use in areas where youth were residents. For adults, drug sales within the neighborhood were negatively associated with drug use, while drug sales in immediately adjacent neighborhoods were positively related to self-reports of drug use. Findings suggest that the areas where rates of drug users are greatest are not necessarily the same area where drugs are sold. Designing strategies to reduce the supply of drugs should receive input from city and regional planners and developers, as well as law enforcement and public health professionals.

An examination of drug activity: effects of neighborhood social organization on the development of drug distribution systems.

OBJECTIVE: The ability to determine the geographic locations of illicit drug markets is central to the development of preventive interventions that address access to drugs and associated problems, such as violence and crime. METHOD: The current study examined individual self-reports of drug activities and demographic information obtained from two waves of a telephone survey of 1704 individuals aged 15 to 29 conducted in 1999 and 2001 across 95 census tracts in a Northern California city and measures of neighborhood characteristics derived from Census 2000 measures. RESULTS: The results of the study showed that, at the individual level, younger people and male respondents reported most drug activities. At the aggregate level, neighborhood poverty was directly related to higher rates of drug activity. Residential stability was found to moderate reports of drug activity observed by African-Americans and young people. CONCLUSION: Social processes reflected in neighborhood characteristics of census tracts influence rates of self-reports of individuals' exposures to drug activities.

An ecological study of the locations of schools and child pedestrian injury collisions.

Geographic studies of the incidence and prevalence of child pedestrian injury collisions in different community environments have been primarily descriptive and idiosyncratic, reflecting one or another likely determinant of the places where these injuries occur. The current study maintains that multiple determinants of child pedestrian injury collisions must be considered in evaluating the unique contributions of any one community feature to injury rates. These features include local characteristics of populations, such as rates of unemployment, and places, such as locations of schools. Schools are one stable geographic feature associated with regular, often concentrated periods of complex and congested traffic patterns. The objective of the present study was to examine annual rates of child pedestrian injury in four California communities with a focus on the unique contribution of schools to injury risk. We predicted that annual numbers of child pedestrian injury collisions (both in-school and summer combined) would be greater in communities with higher youth population densities, more unemployment, fewer high-income households, and higher traffic flow. It was hypothesized that youth population density and its interaction with the number of schools in a given area would be related to greater rates of child pedestrian collisions during in-school months. An ecological approach was taken that divided the four communities into 102 geographic units with an average of 6321 people residing in each unit. Archival data on traffic flow, number of child pedestrian injury collisions and locations of schools were obtained from state agencies. Individual-level data were obtained from a general population survey conducted in the communities. The results showed that annual numbers of injuries were greater in areas with higher youth population densities, more unemployment, fewer high-income households, and greater traffic flow. Annual numbers of injuries during in-school months were greater in areas containing middle schools and greater population densities of youth.