We examined perceived frequency and intensity of racial/ethnic discrimination and associations with high-risk behaviors/conditions among adolescents.
With surveys from 2,490 primarily low socioeconomic status, racial/ethnic minority adolescents, we used regression analysis to examine associations between racial/ethnic discrimination and behavioral health outcomes (alcohol use, marijuana use, physical aggression, delinquency, victimization, depression, suicidal ideation, and sexual behaviors).
Most adolescents (73%) experienced racial/ethnic discrimination and 42% of experiences were “somewhat-” or “very disturbing.” Adolescents reporting frequent and disturbing racial/ethnic discrimination were at increased risk of all measured behaviors, except alcohol and marijuana use. Adolescents who experienced any racial/ethnic discrimination were at increased risk for victimization and depression. Regardless of intensity, adolescents who experienced racial/ethnic discrimination at least occasionally were more likely to report greater physical aggression, delinquency, suicidal ideation, younger age at first oral sex, unprotected sex during last intercourse, and more lifetime sexual partners.
Most adolescents had experienced racial/ethnic discrimination due to their race/ethnicity. Even occasional experiences of racial/ethnic discrimination likely contribute to maladaptive behavioral and mental health outcomes among adolescents. Prevention and coping strategies are important targets for intervention.
To investigate which points of the middle-school drinking distribution are the most influential in the social contagion of drinking across the middle-school years, in order to identify potential social multipliers.
We measured drinking intentions and behaviors by gender, school, and grade among urban middle-school students who participated in Project Northland Chicago in a longitudinal cohort design.
Individual drinking behaviors were consistently influenced by extreme (80th percentile) drinking intentions and behaviors. This effect was mediated through normal or average levels of drinking, over time.
Interventions can target extreme drinkers as the influential persons in middle-school grades.
social norms; drinking; middle school; gender; mediation
To increase understanding of the association between sexual partner meeting venue types (school, through friends or family, organized groups, public places, or on the street) and sexual risk-taking among urban youth.
Data were from 17-18 year olds who reported having had sex (n=1,656) by the time they participated in the 2008-2009 follow-up of a multi-component alcohol preventive intervention, Project Northland Chicago. We used logistic regression to assess the association between partner meeting venue and sexual risk-taking.
Approximately 20% of Chicago adolescents met their most recent sex partner on the street or in public places. Adolescents who met their partner in a public place rather than school were more likely to report having ≥ 3 years age discordant partner [women Odds Ratio (OR) = 7.7, 95% Confidence Interval (CI) = 3.3-17.7, men OR=2.7, 95% CI=1.1, 6.6], alcohol use prior to sex (women OR=3.4, 95% CI 1.8-6.5, men OR=2.4, 95% CI=1.3-4.4), casual partner (women OR = not significant, men OR=2.4, 95% CI=1.3-4.5), anal sex (women OR = not significant, men OR=2.4, 95% CI=1.2-4.9), and unprotected sex (women OR=1.7, 95% CI 1.0-2.7, men OR=1.9, 95% CI=1.1-3.4). Meeting partners on the street was associated with increased probability of alcohol use prior to sex (women OR=2.2, 95% CI 1.1, 4.3, men OR=2.1, 95% CI=1.0-4.6), age discordant partnerships among women (OR=14.2, 95% CI 6.4-31.4), and casual sex partners among men (OR=2.5, 95% CI 1.4-4.8).
Targeting sexual risk-taking with partners selected from public places or the street may improve adolescent HIV preventive interventions.
age discordance; venue; sexual partners; alcohol use; urban adolescents
The current study evaluates neighborhood effects, individual-level effects, and demographic characteristics that influence physically aggressive behavior among urban youth. Using data derived from 5,812 adolescents from Project Northland Chicago (PNC) and Heirarchical Linear Modeling (HLM) techniques, the results suggested that neighborhood problems significantly predicted physical aggression, before and after adjustment for individual-level risk factors (alcohol use, peer alcohol use, lack of adult supervision, and depression) and demographics. After accounting for baseline physical aggression, however, neighborhood problems were no longer a significant predictor of physical aggression. Implications for intervention at both the neighborhood and individual-level and study limitations are also discussed.
Aggression; Neighborhood; Urban; Adolescence; Multilevel
Alcoholic beverage consumption among high school students has shifted from beer to liquor. The current longitudinal study examined the effects of beverage-specific alcohol use on drinking behaviors among urban youth. Data included 731 adolescents who participated in Project Northland Chicago and reported consuming alcohol in 7th grade. Logistic regression tested the effects of beverage-specific use on consequences (e.g., alcohol use in the past month, week, heavy drinking, and ever drunkenness). Compared to wine users, adolescents who reported drinking hard liquor during their last drinking occasion had increased odds of alcohol use during the past month (OR = 1.44; 95% CI = 1.01–2.05), past week (OR = 3.37; 95% CI = 1.39–8.18), and ever drunkenness (OR = 1.56; 95% CI = 1.07–2.29). Use of hard liquor was associated with increased risk of alcohol-related consequences. Early selection of certain alcoholic beverages (e.g., hard liquor) may result in negative health outcomes and problematic alcohol use over time.
We examined whether schools achieving better than expected educational outcomes for their students influence the risk of drug use and delinquency among urban, racial/ethnic minority youth. Adolescents (n=2,621), who were primarily African American and Hispanic and enrolled in Chicago public schools (n=61), completed surveys in 6th (aged 12) and 8th (aged 14) grades. Value-added education was derived from standardized residuals of regression equations predicting school-level academic achievement and attendance from students’ sociodemographic profiles and defined as having higher academic achievement and attendance than that expected given the sociodemographic profile of the schools’ student composition. Multilevel logistic regression estimated the effects of value-added education on students’ drug use and delinquency. After considering initial risk behavior, value-added education was associated with lower incidence of alcohol, cigarette and marijuana use; stealing; and participating in a group-against-group fight. Significant beneficial effects of value-added education remained for cigarette and marijuana use, stealing and participating in a group-against-group fight after adjustment for individual- and school-level covariates. Alcohol use (past month and heavy episodic) showed marginally significant trends in the hypothesized direction after these adjustments. Inner-city schools may break the links between social disadvantage, drug use and delinquency. Identifying the processes related to value-added education in order to improve school environments is warranted given the high costs associated with individual-level interventions.
Schools; Drug use; Delinquency; Urban; Adolescents
To estimate trajectories of aggression among African Americans and Hispanics using a longitudinal sample of urban adolescents, and test multiple domains of risk factors to differentiate profiles of aggression.
Participants included 3,038 adolescents followed from 6th–8th grade. Trajectories of aggression were estimated for African Americans and Hispanics separately, and multinomial regression procedures were used to evaluate the effect of multiple domains of risk and protective factors. Mediation analyses were conducted to evaluate the indirect effects of contextual variables on aggression.
Four profiles of aggression were identified. Among Hispanics, groups included: 1) low-aggression, 2) desistors, 3) escalators, and 4) consistent aggression; among African Americans: 1) low-aggression, 2) escalators, 3) moderate-consistent aggression, and 4) consistent aggression. Differences in the multiple domains of risk factors emerged between racial/ethnic groups.
Contextual variables (peer alcohol use, adult alcohol consumption, and home access to alcohol) increased risk for aggression differentially by racial/ethnic group.
trajectory; aggression; longitudinal; adolescents; drug; alcohol
To investigate whether smoking prevalence in grade-level networks influences individual smoking, suggesting that peers are important social multipliers in teen smoking.
We measured gender-specific, grade-level recent and life-time smoking among urban middle-school students who participated in Project Northland Chicago in a longitudinal cohort design.
Within schools, grade-level recent smoking had comparable effects on girls’ and boys’ individual-level smoking. Grade-level lifetime smoking had a greater effect on girls’ smoking.
Interventions can target middle school classes and schools broadly, without making the identification of friendship networks a concern.
social norms; smoking; middle school; gender
Living in poverty and living in areas of concentrated poverty pose multiple risks for child development and for overall health and wellbeing. Poverty is a major risk factor for several mental, emotional, and behavioral disorders, as well as for other developmental challenges and physical health problems. In this paper, the Promise Neighborhoods Research Consortium describes a science-based framework for the promotion of child health and development within distressed high-poverty neighborhoods. We lay out a model of child and adolescent developmental outcomes, and integrate knowledge of potent and malleable influences to define a comprehensive intervention framework to bring about a significant increase in the proportion of young people in high-poverty neighborhoods who will develop successfully. Based on a synthesis of research from diverse fields, we designed the Creating Nurturing Environments framework to guide community-wide efforts to improve child outcomes and reduce health and educational inequalities.
child; adolescent; health; wellbeing; poverty; framework
The purpose of this study was to explore how behavioral, intra-personal and socio-environmental factors were associated with the likelihood of having at least one older friend.
Participants included 3709 ethnically-diverse 8th grade students in the Project Northland Chicago intervention trial. Socio-demographic characteristics included gender, family composition, language spoken at home, race/ethnicity, and age. Behavioral factors included cigarette, alcohol, and marijuana use, depressed feelings, willingness to wear alcohol-branded merchandise, and violent and delinquent behavior. Intrapersonal factors included low refusal self efficacy and outcome expectations and expectancies. Socio-environmental factors included alcohol offers and access, normative estimates and expectations, and peer alcohol use. Having an older friend was defined as having at least one friend aged 16 or older (students’ mean age=14.2). Logistic mixed-effects regression models were used and controlled for gender, race/ethnicity, treatment status, and age.
Females and older eighth graders were significantly more likely to have at least one older friend. Students who scored higher on all of the behavioral, intra-personal and socio-environmental risk factors were significantly more likely to have at least one older friend. Significant gender interactions were found for several of the relationships.
Overall this study found multiple risk-related factors are associated with having older friends in eighth grade. Particularly important factors appear to be cigarette, marijuana and alcohol use, having friends who use alcohol, having increased alcohol offers, and being willing to wear or use alcohol-branded merchandise.
Peers; Friends; Risk Behaviors; Risk Factors; Adolescence
Several studies have investigated factors associated with physical aggression during adolescence. Yet, little is known about the longitudinal relationship between drug use, particularly alcohol use, and physical aggression among minority youth. The present study examined the effects of alcohol and substance use at age 11 on trajectories of physical aggression over time (ages 12–14) among urban adolescents from Chicago, IL. Data from the Project Northland Chicago (n = 3038, 49.4% female) was used. The current study sample included 1,160 Black, 1,015 Hispanic and 863 White/other adolescents for a total of 3,038 adolescents. Four trajectories of physical aggression were identified: Non-aggressive (16%), Desistors (9%), Escalators (20%) and Chronic Aggressive (55%). After adjusting for physical aggression behaviors, delinquent friends, lack of supervised time, demographic variables, smoking and marijuana use, past year alcohol users at age 11 were 2.1 times more likely to be “Escalators” and 1.9 times more likely to be in the “Chronic Aggressive” group. Gender and ethnic differences were also observed in the trajectories of physical aggression. Black youth were 2.5 times more likely to be in the “Chronic Aggressive” group. Findings highlight the importance of targeting alcohol prevention to reduce physical aggression among urban young adolescents.
Physical aggression; Group-based; Longitudinal; Urban; Adolescents; Alcohol
A growing body of literature has recently emerged examining sex-specific pathways of offending. Yet, despite significant gains, this area of research is still rather underexplored. With a particular focus on the role of delinquent peers, this current study investigates the sex similarities/differences in offending trajectories among a large sample of urban Chicago male and female youth (n=3,038) from 6th through 8th grade (e.g., ages 12–14). The results suggest that the pathways of offending appear to be more similar than different across sex, and that associating with delinquent peers is significantly related to baseline delinquency. Furthermore, delinquent peers significantly distinguished the moderate and high-rate trajectory groups from the non-delinquents for both males and females, yet once estimated in a more fully specified model, the role of delinquent peers appeared to be indirect (operating through its effect on baseline delinquency). Study limitations and implications for theory and policy are also discussed.
Sex; Trajectories; Deliquency; Social learning theory; Deliquent peers
Growth curve models examined changes in adolescent self-reported parent-child communication conditional on family meal frequency over a 3.5 year period among a population of racially-diverse, low-income adolescents from an urban environment (n = 4750). Results indicated that although both family dinner frequency and adolescent perceptions of parent-child communication scores were characterized by negative linear growth over time (both p < .0001), family dinner frequency was positively associated with adolescent perceptions of parent-child communication scores over time (p < .0001). Study findings suggest that families with teenagers may enhance parent-child communication and ultimately promote healthy adolescent development by making family dinner a priority. Additionally, the communication benefits of family dinner at the beginning of 6th grade may be protective through 8th grade.
adolescents; family dinner; family meals; parent-child communication; race/ethnicity; urban
This study sought to identify trajectories of physical aggression among urban Hispanic youth, and to examine the effects of risk and protective factors at age 11 on trajectories of physical aggression over time (ages 12–18). Relying on data from 731 urban Hispanic adolescents from Project Northland Chicago (PNC), latent trajectory modeling was used to determine the number of trajectories, and multinomial logistic regression was used to identify the predictors associated with trajectory membership. The results suggested five trajectories of physical aggression (non-aggressive, low stable, escalators, early-rapid desistors, and high aggression/moderate desistors). After adjusting for several risk and protective factors, language preference (e.g. speaking Spanish at home) was identified as a protective factor, while indirect exposure to alcohol, sadness/depression, fewer negative alcohol-related attitudes, and threatening to fight were associated with increased risk for physical aggression. Study implications indicate that early, multilevel prevention efforts are necessary to deter the initiation and promote the desistance of physical aggression over time among urban Hispanic adolescents.
Physical aggression; Hispanics; Longitudinal; Urban; Adolescents; Alcohol; Trajectories
This study examined associations between patterns of alcohol use initiation and progression from age 12 to 14 years and recent cigarette and marijuana use, and violent and delinquent behavior at age 14. The study sample (n=2,193) was predominantly African American or Hispanic (43% and 37%, respectively) and low-income (68% receiving free, or reduced price, lunch). They completed classroom-based surveys when in 6th–8th grades. Multilevel latent class analyses were used to identify the heterogeneous alcohol use trajectories. Linear and logistic mixed-effects regression was then used to examine the association between these patterns and high-risk behaviors in 8th grade. Five alcohol use trajectories were identified: (1) No Use (63.3%), (2) Onset of Consistently Infrequent Use at Age < 12 (13.3%), (3) Onset of Monthly Use at Age 14 (9.9%), (4) Onset of Monthly Use at Age 13 to Heavy Use at Age 14 (6.6%), and (5) Onset of Consistently Heavy Use at Age 12 (6.9%). Relative to non-users, membership in any of the alcohol use trajectory classes was significantly associated with greater past month cigarette and marijuana use, as well as violent behaviors in 8th grade. Higher levels of delinquent behaviors were significantly associated with membership in all but one of the alcohol use trajectory classes relative to the “no use” class. Results suggest that any use of alcohol in early adolescence is associated with other high-risk behaviors and support the critical need for efforts to prevent early initiation and progression of alcohol use among youth as a key component to prevent future high-risk behaviors.
alcohol use; high-risk behaviors; adolescent; trajectory classes
The purpose of this study was to determine if parents’ and children’s reports of parenting practices were correlated, if the reports were differentially associated with alcohol use, and which report had the strongest association with alcohol use.
Cross-sectional and longitudinal.
Public schools, Chicago, Illinois.
Participants included 1373 ethnically-diverse students and parents involved in an alcohol use prevention intervention. Surveys were conducted in sixth grade and eighth grade. Mixed-effects regression analyses were used to model relationships cross-sectionally and longitudinally.
Parents’ and children’s perceptions of parenting practices, while significantly correlated, were not strongly associated. Analyses within each parenting domain found parents’ report of parental monitoring and children’s reports of alcohol-specific communication, general communication, and relationship satisfaction were associated with alcohol use behaviors and intentions. After adjusting for all other parenting practices, parents’ report of parental monitoring and children’s report of alcohol-specific communication were most strongly related to alcohol use behaviors and intentions both cross-sectionally and longitudinally.
When comparing results across studies, it is important to identify whose report was used, parent or child, as the results may differ based on reporter. Studies with limited resources may consider using parents’ reports about parental monitoring and using children’s reports for alcohol-specific communication, general communication, and relationship satisfaction.
Parenting; parent-child relationships; alcohol use; early adolescence
Mixed effect models have become very popular, especially for the analysis of longitudinal data. One challenge is how to build a good enough mixed effects model. In this paper, we suggest a systematic strategy for addressing this challenge and introduce easily implemented practical advice to build mixed effect models. A general discussion of scientific strategies motivates the recommended five step procedure for model fitting. The need to model both the mean structure (the fixed effects) and the covariance structure (the random effects and residual error) creates the fundamental flexibility and complexity. Some very practical recommendations help conquer the complexity. Centering, scaling, and full-rank coding all predictor variables radically improves the chances of convergence, computing speed, and numerical accuracy. Applying computational and assumption diagnostics from univariate linear models to mixed model data greatly helps detect and solve related computational problems. Applying computational and assumption diagnostics from univariate linear models to mixed model data can radically improve the chances of convergence, computing speed, and numerical accuracy. The approach helps fit more general covariance models, a crucial step in selecting a credible covariance model needed for defensible inference. A detailed demonstration of the recommended strategy is based on data from a published study of a randomized trial of a multicomponent intervention to prevent young adolescents' alcohol use. The discussion highlights a need for additional covariance and inference tools for mixed models. The discussion also highlights the need for improving how scientists and statisticians teach and review the process of finding a good enough mixed model.
Longitudinal data analysis; mixed effects models; model building
We examined relationships between alcohol-related neighborhood context, protective home and family management practices, and alcohol use among urban, racial/ethnic minority, adolescents. The sample comprised 5,655 youth who were primarily low SES (72%), African American (43%) and Hispanic (29%). Participants completed surveys in 2002–2005 (ages 11–14 years). Items assessed alcohol use, accessibility of alcohol at home and parental family management practices. Neighborhood context measures included: (1) alcohol outlet density; (2) commercial alcohol accessibility; (3) alcohol advertisement exposure; and (4) perceived neighborhood strength, reported by parents and community leaders. Structural equation modeling was used to assess direct and indirect relationships between alcohol-related neighborhood context at baseline, home alcohol access and family management practices in 7th grade, and alcohol use in 8th grade. Neighborhood strength was negatively associated with alcohol use (β=−0.078, p≤.05) and exposure to alcohol advertisements was positively associated with alcohol use (β=0.043, p≤.05). Neighborhood strength and commercial alcohol access were associated with home alcohol access (β=0.050, p≤.05 and β=−0.150, p≤.001, respectively) and family management practices (β=−0.061, p≤.01 and β=0.083, p≤.001, respectively). Home alcohol access showed a positive association with alcohol use (β=0.401, p≤.001). Tests for indirect effects suggest that home alcohol access may partially mediate the relationship between neighborhood strength and alcohol use (β=0.025, p<.062). Results suggest inner-city parents respond to environmental risk, such that as neighborhood risk increases, so also do protective home and family management practices. Parent engagement in restricting alcohol access and improving family management practices may be key to preventive efforts to reduce alcohol use.
Adolescents; Communities; Family; Context; Alcohol
This study identified heterogeneous classes of alcohol-related neighborhood characteristics to which multi-ethnic, early adolescents in urban communities are exposed. The sample comprised 4,215 youth from 42 community areas in Chicago, Illinois who completed surveys at the beginning of 6th grade (2002). Neighborhood measures included: (1) mean number of alcohol outlets per 1,000 population per community area; (2) alcohol purchase attempt rate by pseudo-underage youth; (3) average number of alcohol advertisements within 1500 feet of each school per community; and (4) a Census 2000-based deprivation index. Parents and community leaders provided data on perceived neighborhood problems and parental prevention actions, and neighborhood strength and preventive action by communities, law enforcement, and community organizations, respectively. Multilevel latent class analysis identified the number and characteristics of heterogeneous latent neighborhood classes in which these youth are exposed. Five classes best described the heterogeneity among the sample: (1) Low social capital/low exposure/high access to alcohol (19.8%), (2) Low social capital/low exposure/low access to alcohol (24.5%), (3) Moderate social capital/low exposure/high access to alcohol (30.0%), (4) Moderate social capital/moderate exposure/low access to alcohol (20.1%), and (5) High social capital/moderate exposure/high access to alcohol (5.6%). The racial/ethnic distribution among the classes varied considerably. Results suggest there is substantive heterogeneity among this seemingly homogeneous urban population. Further, they highlight the socioeconomic disadvantage of these inner-city communities and the resource disparity across the racial/ethnic groups. Understanding the nuances among communities may lend to development of more efficacious preventive interventions and policy initiatives, inform theory, and help prioritize limited resources.
Adolescents; Communities; Alcohol access; Social capital; Latent class analysis
Young adolescent alcohol users drink at higher rates than their peers throughout adolescence and appear to be less amenable to intervention. This study compares those who reported alcohol use in the past year to those who reported no use in a multiethnic, urban sample of sixth graders in 61 schools in Chicago in 2002 (N = 4,150). Demographic, behavioral, intrapersonal, and socioenvironmental factors were identified based on behavioral theories and potential mediators of the Project Northland Chicago intervention. Single and multiple regression models were created for users and nonusers to determine associations between these factors and alcohol use behavior and intentions. The multiple regression models explained 35% and 56% of the variance in alcohol use behavior and intentions between students for nonusers and users, respectively. Results suggest that primary prevention programs for alcohol use should occur prior to sixth grade, particularly for the substantial group at high risk for early use.
alcohol use; adolescents; nonusers
The objectives of this study were to determine: (1) if the number of outdoor alcohol advertisements around schools varied by ethnicity of students in the school, and (2) how the content of alcohol advertising around schools varied by the ethnicity of students in the school.
All outdoor alcohol advertisements within 1500 feet of 63 Chicago schools were documented and coded for content and theme. On average, the ethnic make-up of schools was 54.9% African American, 24.4% Hispanic, and 16.2% White; 79.7% of students were low SES. To compare the mean number and type of ads by ethnicity of the school, schools were coded by ethnicity (i.e. 20% or more Hispanic students compared with less than 20% Hispanic students).
Youth attending schools with 20% or more Hispanic students were exposed to 6.5 times more alcohol advertising than students attending schools with less than 20% Hispanic students. Schools with 20% or more Hispanic students were also surrounded by more beer advertising and alcohol advertisements on bars and liquor stores.
Alcohol advertising is more prevalent around schools with 20% or more Hispanic students. Policies should be considered to reduce the amount of alcohol advertising around schools.
Alcohol advertising; Hispanic youth; Adolescents
The purpose of the present study is to investigate the relationships between alcohol-related informal social control and parental monitoring on alcohol use, behavior and intentions; violent behavior; and delinquent behavior in a racially diverse population of young urban adolescents. Baseline surveys were administered to 6th grade male and female students in 61 urban Chicago schools as part of Project Northland Chicago, a group randomized trial for the prevention/reduction of substance use. A subset of their parents (n=3034) was also surveyed regarding alcohol use, violence, and delinquency and related issues. Structural equation modeling was used to assess relationships between alcohol-related informal social control (as measured by parental perceptions of neighborhood action regarding youth drinking) and parental monitoring (as reported by parents), and three adolescent outcomes (alcohol use, behaviors and intentions; violent behavior; and delinquent behavior; as reported by teens). Associations between alcohol-related informal social control and parental monitoring were positive and significant (p<.001). Direct paths from parental monitoring to all three adolescent outcomes were negative and statistically significant (alcohol use, behaviors and intentions, p<.001; violent behavior, p<.001; and delinquent behavior, p<.001). Alcohol-related informal social control was not significantly associated with adolescent outcomes. Efforts to engage parents to be more active in monitoring adolescents’ activities may be related to lower levels of underage drinking, violence and delinquency among both female and male urban youth. Neighborhood norms and action against teenage drinking may be too distal to adolescent outcomes to be directly associated.
Parental monitoring; Alcohol-related informal social control; Adolescent behaviors; Alcohol; Delinquency; Violence
Examine sources of alcohol over time in a large, ethnically-diverse adolescent population from a poor, urban environment.
Surveys were administered at four time points (6th–8th grades) assessing demographic characteristics, past year alcohol use, and sources of alcohol to youth in Chicago, Illinois 2003–2005. Growth curve analysis was used to examine alcohol access trends among all alcohol using youth and consistent alcohol users. Interactions by race and gender were tested.
Social sources of alcohol were the most prevalent source over time. Parents were the primary source of alcohol, but their prominence significantly decreased over time. Taking alcohol from home, and getting alcohol from other adults, individuals under age 21, and commercial sources significantly increased as sources of alcohol over time. Males were significantly more likely than females to get alcohol from commercial sources and friends’ parents.
Greater attention for reducing social access to alcohol, particularly among parents, is needed for alcohol prevention efforts prior to and during middle school.
adolescents; urban; diverse; race/ethnicity; alcohol; prevention; intervention; group randomized trial; Project Northland Chicago; commercial; alcohol sources; social access; growth curve modeling