The social context of adolescent smoking: a systems perspective

Simulating social network-based interventions for adolescent cigarette smoking

Social network-based adolescent substance use interventions have demonstrated potential for reducing adolescent cigarette smoking. This approach is premised upon leveraging youths' social networks for the diffusion of peer influence. Determining which adolescents to select in network interventions for reducing smoking is a major consideration. We utilize a simulation approach that first estimates Stochastic Actor-Oriented models (SAOM) of adolescent smoking using data from two of the largest schools from the longitudinal saturation sample of the National Study of Adolescent to Adult Health (Add Health) (n = 3,154). We then conduct Agent-Based Simulation models which mimic the consequences of intervention strategies selecting adolescents in network positions and structures that are salient for smoking and the diffusion of peer influence within school-based networks, and we select adolescents smoking at different levels. Our findings indicate that selecting adolescents occupying central network positions yielded the greatest reductions in the number of smokers in a school, one year post intervention. Moreover, our findings indicate that in the school with the higher smoking prevalence, there was a beneficial network multiplier effect one year later, which resulted in more non-smokers than those smokers initially intervened upon. When examining the effects of varying the magnitude of peer influence, we find that targeting central positions in networks led to even greater decreases in smoking in schools with higher levels of peer influence. Our findings highlight interdependence and sensitivity of peer influence to network position and have implications for informing school-based network interventions for adolescent smoking.

Determinants of knowledge of risks associated with cigarette smoking among adolescents in Scotland

Cigarette smoking remains a significant public health concern, particularly among adolescents. This study aimed to assess adolescents' knowledge of the risks associated with smoking in Scotland and explore the factors influencing this knowledge. A cross-sectional analysis was conducted using data from the 2018 Scottish Schools Adolescent Lifestyle and Substance Use Survey. The sample included 23 365 adolescents from Secondary 2 (n = 12 558) and Secondary 4 (n = 10 807). Demographic, behavioural, contextual, and health-related factors were examined as predictors of smoking risk knowledge, with a cumulative knowledge score based on responses to seven smoking-related questions. Poisson regression was used to examine associations between predictors and cumulative knowledge scores, and adjusted incidence rate ratios (IRRs) with 95% confidence intervals (CIs) were reported. Overall, 38.2% (n = 8928) of participants answered all questions correctly, with a median score of 6 (IQR: 5-7). While 83.6% (n = 19 540) scored at least 5, knowledge gaps remained, particularly concerning the risks of light smoking. Boys had lower scores than girls (IRR = 0.97, 95% CI: 0.96-0.97, P < .001), and adolescents from less deprived areas scored higher than those from more deprived areas (IRR = 1.02, 95% CI: 1.01-1.03, P = .006). Non-smokers had higher scores than smokers (IRR = 1.08, 95% CI: 1.05-1.10, P < .001), and adolescents confident in accessing health information scored significantly higher (IRR = 1.13, 95% CI: 1.11-1.15, P < .001). Peer influence was evident, as adolescents with friends who smoked had lower scores (IRR = 0.96, 95% CI: 0.94-0.98, P < .001). Adolescents in Scotland generally understand the risks of cigarette smoking, but notable gaps persist, especially regarding dangers of light smoking.

Cross-sectional social network study of adolescent peer group variation in substance use and mental wellbeing

Adolescent health-related behaviours and outcomes are shaped by their peers through various social processes. Research using network data on friendship ties has uncovered evidence for processes such as peer influence and imitation. Much less is known about how the structure of small groups within a network, network communities that represents its meso level, affect individuals. The structure and composition of peer groups could play an important role in shaping health behaviour but knowledge of the effects of groups is limited. We used data from The Peers and Levels of Stress study, a cross-sectional social network study conducted in 2006 of 22 secondary schools in Glasgow, Scotland. Students from one year group (15-16 yrs., N= 3148; 50.8% women) provided information on socio-demographics, health behaviour and friendships via a questionnaire. Dependent variables were substance use and general mental wellbeing as composite scores on different measures. We used a series of multilevel models with students (level 1), network communities (peer groups) identified by the Walktrap algorithm (level 2), and schools (level 3). We found substantial and moderate clustering at the peer group level for substance use and mental wellbeing, respectively. Larger and more transitive groups were associated with less substance use, but worse mental wellbeing. Addressing the methodological gap regarding the influence of the choice of group detection method on findings, we repeated our analysis using nine additional methods. The choice of the method somewhat influenced peer group variance and greatly influenced association of peer group properties with health. This study makes two key contributions to school-health improvement research. Beyond describing the peer group clustering health outcomes, this is the first demonstration that structural and compositional characteristics of peer groups are associated with individual health, while highlighting the sensitivity of findings to group detection method used.

Impact of licit and illicit substances on the oral health-related quality of life in adolescents

OBJECTIVE

To assess the impact of the consumption of licit and illicit substances on the oral health-related quality of life (OHRQoL) of adolescents from public schools in the south of Brazil.

METHODS

This cross-sectional study was carried out with a random sample of adolescents aged between 17 and 18 years old from Santa Maria, Brazil. The consumption of licit and illicit substances was measured through a self-administered questionnaire with questions from the National Survey of Scholar Health. The OHRQoL was collected using the Brazilian short version of Child Perceptions Questionnaire 11-14 (CPQ11-14). Multilevel Poisson regression models were used to estimate the association between the outcome and the explanatory variables where the adolescents (first level) were nested in their schools (second level).

RESULTS

A total of 768 adolescents were evaluated. Of these, about 15.6% have already used illegal substances. Adolescents who reported the use of illicit substances had 28% higher CPQ11-14 scores when compared to their counterparts. Alcohol use was also related to worse levels of OHRQoL, while the consumption of cigarettes acted as a protective factor.

CONCLUSIONS

This study found an association between the use of alcohol and illicit drugs with worse levels of OHRQoL.

An examination of the protective role of internalizing symptoms in adolescent substance use

Although psychological symptoms are broadly considered to be risk factors for substance use, internalizing symptoms may be associated with lower risk for adolescent substance use after controlling for co-occurring externalizing symptoms. The present study explored two potential mediators of this protective association between internalizing symptoms and adolescent substance use: popularity and harm avoidance. The study used data from the Colorado Longitudinal Twin Study (LTS) and Colorado Adoption Project (CAP). Annual assessments of internalizing and externalizing symptoms and social competence were completed by parents and teachers at participant ages 7 to 16. Harm avoidance and substance use were assessed at age 17. In this sample, internalizing symptoms were associated with less frequent substance use, controlling for externalizing symptoms. We did not find evidence that popularity or harm avoidance accounts for the protective association of internalizing symptoms with adolescent substance use. Teacher-reported popularity was associated with less frequent substance use, suggesting that social connectedness in the school context may be a protective factor for adolescent substance use. Harm avoidance was not associated with substance use after accounting for internalizing and externalizing symptoms.

Determinant of Smoking Behavior among Elementary Student in Indonesia: A Structure Equation Model

BACKGROUND: Initial smoking exposure may occur during early adolescence (aged 10–12 years old), and it increases overtime. Although several factors for smoking behaviors exist among adolescents, there are few studies address determinant of smoking behavior by adding others variables in theory of plan behavior such as smoking refusal skills, self-regulation, parenting, family function, environment, and culture. AIM: The aim of this study was, therefore, to evaluate the determinant of smoking behavior among elementary student in Indonesia using a structural equation model. METHODS: A cross-sectional survey was carried out from June to October 2019 in West Java, Indonesia. For each school, students were selected using a systematic random sampling technique. The study included girls and boys ages 10–12. The consent was obtained by the parent or guardian. Structural equation modeling was used for analysis. RESULTS: The mean age was 10.56 years (SD = 0.37). About 28.6% of them were currently smoking with aged of first use was 10.02 (SD = 0.19). More than half (56%) of their family were currently smoking too and friend smoking was 41.7%. The final model accounted for 27% and 39% of the variance of intention and smoking behavior, respectively, has both direct and indirect effects through empowerment on self-care behaviors toward pregnancy-related complication. CONCLUSION: The present study was intended to expand the theory of planned behavior by including additional variables in its model: Smoking refusal skills, self-regulation, parenting, family function, environment, and culture. This study also provides a significant contribute for clinical a practice and policy-maker as a basic data to establish future intervention to promote no tobacco use among elementary student to achieve optimal well-being to prevent a fatal disease.

Protocol for the evaluation of cost-effectiveness and health equity impact of a school-based tobacco prevention programme in a cluster randomised controlled trial (the TOPAS study)

INTRODUCTION

Despite a long-term downward trend in smoking prevalence, tobacco remains the number one risk factor for death and disability in Sweden. Globally, tobacco use generates a substantial economic burden for health systems and is also a major driver of socioeconomic inequalities in health. This article describes the planned cost-effectiveness and health equity impact evaluation of a multicomponent school-based programme to prevent the onset of tobacco use in adolescents.

METHODS AND ANALYSIS

Cost-effectiveness of the multicomponent Tobacco-Free Duo programme will be evaluated against the educational component of the same programme only. An incremental cost-effectiveness ratio (ICER) will be calculated in terms of the cost per case prevented using the trial primary outcome and within-trial payer costs. If the ICER is negative, an incremental net benefit ratio will be calculated. Robustness of the results will be assessed through one-way sensitivity analyses. The slope index of inequality will be computed to assess the potential impact of the Tobacco-free Duo programme on education-related inequalities in the onset of smoking and in adult smoking cessation, comparing the two trial arms.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Regional Ethics Review Board, Umeå (registration number 2017/255-31). The Public Health Agency of Sweden commissioned the study. The findings will be disseminated internationally within academia and to national and local policy-makers.

TRIAL REGISTRATION NUMBER

ISRCTN52858080; Pre-results.

Exposure to new smoking environments and individual-level cigarette smoking behavior: Insights from exogenous assignment of military personnel

Despite overall declines in cigarette smoking prevalence in the United States (U.S.) in the past several decades, smoking rates remain highly variable across geographic areas. Past work suggests that smoking norms and exposure to other smokers in one's social environment may correlate with smoking risk and cessation, but little is known about how exposure to other smokers in one's community is causally linked to smoking behavior - in part due to endogeneity and inability to randomly assign individuals to different 'smoking environments.' The goal of this study was to evaluate how exposure to localities with high population-level smoking prevalence affects individual-level cigarette smoking behaviors, including quitting. The study addresses key limitations in the literature by leveraging a unique natural experiment: the plausibly exogenous compulsory assignment of military personnel to installations. Logistic and multivariate regressions estimated cross-sectional associations between smoking/quitting behaviors and our proxy for social environments for smoking, county-level smoking prevalence (CSP). Across 563 U.S. counties, CSP ranged from 3.8 to 37.9%. Among the full sample, a 10 percentage point increase in CSP was associated with an 11% greater likelihood of smoking. In subgroup analyses, young adults, women, those without children in the household, and risk/sensation-seekers were more likely to smoke and less likely to quit when exposed to counties with higher CSP. Relocation to areas with high population-level smoking prevalence may increase likelihood of smoking and impede quitting, and may disparately affect some population subgroups. Findings provide novel evidence that community smoking environments affect adult smoking risk and underscore a need for sustained, targeted efforts to reduce smoking in areas where prevalence remains high.

Keeping Each Other Accountable: Social Strategies for Smoking Cessation and Healthy Living in Vietnamese American Men

Vietnamese American males have high smoking rates. This study explored social support mechanisms provided by lay health workers (LHWs) and family members through a smoking cessation intervention. Eight focus groups (N = 54) were conducted in Vietnamese stratified by intervention arms (Tobacco [experimental] and healthy living [control]) with 18 smokers, 18 family members, and 18 LHWs. Smokers reported feeling more accountable for their health behaviors, and smoking changes were reinforced by family members, peers, and LHWs through conversations facilitated during and outside the program. Culturally appropriate interventions with multiple social support mechanisms may reduce smoking in minority populations.

Individual- and group-level network-building interventions to address social isolation and loneliness: A scoping review with implications for COVID19

PURPOSE

Worldwide mandates for social distancing and home-quarantine have contributed to loneliness and social isolation. We conducted a systematic scoping review to identify network-building interventions that address loneliness and isolation, describe their components and impact on network structure, and consider their application in the wake of COVID19.

METHODS

We performed forward and backward citation tracking of three seminal publications on network interventions and Bibliographic search of Web of Science and SCOPUS. We developed data charting tables and extracted and synthesized the characteristics of included studies, using an iteratively updating form.

FINDINGS

From 3390 retrieved titles and abstracts, we included 8 studies. These interventions focused on building networks at either individual- or group-levels. Key elements that were incorporated in the interventions at varying degrees included (a) creating opportunities to build networks; (b) improving social skills; (c) assessing network diagnostics (i.e. using network data or information to inform network strategies); (d) promoting engagement with influential actors; and (e) a process for goal-setting and feedback. The effect of interventions on network structures, or the moderating effect of structure on the intervention effectiveness was rarely assessed.

CONCLUSIONS

As many natural face-to-face opportunities for social connection are limited due to COVID19, groups already at risk for social isolation and loneliness are disproportionately impacted. Network-building interventions include multiple components that address both the structure of individuals' networks, and their skills and motivation for activating them. These intervention elements could be adapted for delivery via online platforms, and implemented by trained facilitators or novice volunteers, although more rigorous testing is needed.

Perceived Social Acceptability and Longitudinal Trends in Adolescent Cigarette Smoking

The current study uses methods from social network analysis to predict longitudinal trends in adolescent cigarette smoking based on perceived social acceptability from friends, in addition to typical measures of peer influence (e.g., self-reported cigarette use of friends). By concurrently investigating the role of perceived social acceptability of smoking and peer influence, the current study offers new insight into the mechanisms through which peers influence adolescent smoking. Two waves of data from five high schools within one US school district (n = 1563) were used. Stochastic actor-based models simultaneously estimated changes in smoking predicted by perceived social acceptability and peer influence. Findings demonstrate that adolescents with higher perceived social acceptability of cigarette use increased cigarette smoking over time. Conversely, support for peer influence on smoking was not found after controlling for the effects of perceived social acceptability. The results suggest that perceived social acceptability regarding cigarette smoking rather than self-report of cigarette use among friends is predictive of future smoking behavior. Consequently, the findings highlight the need for prevention efforts to take into account the multifaceted dynamics between adolescent smoking and friendships. Programs that address peer influence alone, without considering peer mechanisms such as perceived social acceptability, are at risk of ignoring critical avenues for prevention.

Peer social network processes and adolescent health behaviors: A systematic review

Research has highlighted the importance of peers for determining health behaviors in adolescents, yet these behaviors have typically been investigated in isolation. We need to understand common network processes operating across health behaviors collectively, in order to discern how social network processes impact health behaviors. Thus, this systematic review of studies investigated adolescent peer social networks and health behaviors. A search of six databases (CINAHL, Education Resources Information Centre, Embase, International Bibliography of the Social Sciences, Medline and PsycINFO) identified 55 eligible studies. The mean age of the participants was 15.1 years (range 13-18; 51.1% female). Study samples ranged from 143 to 20,745 participants. Studies investigated drinking (31%), smoking (22%), both drinking and smoking (13%) substance use (18%), physical activity (9%) and diet or weight management (7%). Study design was largely longitudinal (n = 41, 73%) and cross-sectional (n = 14, 25%). All studies were set in school and all but one study focused on school-based friendship networks. The Newcastle-Ottawa Scale was used to assess risk of bias: studies were assessed as good (51%), fair (16%) or poor (33%). The synthesis of results revolved around two network behavior patterns: 1) health behavior similarity within a social network, driven by homophilic social selection and/or social influence, and 2) popularity: health behavior engagement in relation to changes in social status; or network popularity predicting health behaviors. Adolescents in denser networks had statistically significant lower levels of harmful behavior (n = 2/2, 100%). Findings suggest that social network processes are important factors in adolescent health behaviors.

"It's just a way of fitting in:" Tobacco use and the lived experience of lesbian, gay, and bisexual appalachians

Lesbian, gay, and bisexual (LGB) people are affected by multiple health disparities and risk factors, including tobacco use. Few studies to date have examined tobacco use specifically in rural LGB populations, and none has investigated the intersections of identity, rural LGB culture, and tobacco. The purpose of this study was to explore the perspective of Appalachian LGB people regarding tobacco use.

METHODS

. Nineteen LGB-identified Appalachian residents participated in audiotaped, semi-structured interviews. Two authors analyzed and coded transcripts through constant comparison, and determined themes through consensus.

RESULTS

Five themes emerged: the convergence of Appalachian and LGB identities, tacit awareness of LGB identity by others, culture and tobacco use, perceived associations with tobacco use, and health beliefs and health care.

CONCLUSIONS

LGB Appalachians connect stress and culture to tobacco, but seem less aware that partial concealment of their identity might be a source of the stress that could influence their smoking.

Adolescent social networks: general and smoking-specific characteristics associated with smoking

OBJECTIVE

Converging lines of research suggest that adolescents' smoking behaviors are strongly influenced by the characteristics of their social network and the social processes their network facilitates. The primary goal of this study was to conduct a detailed comparison of the social networks of adolescent smokers and nonsmokers to determine what aspects relate the most to smoking status. A secondary goal was to conduct within-group analyses to examine relationships between key measures of behavior-specific social support and (a) smoking susceptibility among nonsmokers, and (b) readiness to quit smoking among smokers.

METHOD

A matched sample of 190 adolescent smokers and nonsmokers (Mage = 16.8 years; 51% female) completed a questionnaire in which they nominated and reported on up to 10 important people in their lives. This measure allowed us to examine adolescents' overall networks (both peers and family) and to investigate numerous aspects, including general network characteristics (e.g., size of network, average contact with network members), social support (e.g., importance of people in the network), and the pervasiveness of smoking in the network (e.g., percentage of smoking peers).

RESULTS

The pervasiveness of smoking in adolescents' social network was the strongest distinguisher of smokers versus nonsmokers. In addition, behavior-specific social support was strongly associated with susceptibility to initiate smoking among nonsmokers and readiness to quit among smokers.

CONCLUSIONS

This research offers insight into potential targets for prevention and early intervention by demonstrating how social networks can both promote and attenuate risk for smoking.

Tobacco and alcohol use in adolescents with unplanned pregnancies: relation with family structure, tobacco and alcohol use at home and by friends

BACKGROUND

Recent publications show that smoking and alcohol use among adolescents with unplanned pregnancy is increasing and the causes need to be further studied.

OBJECTIVE

To determine the association between living in a non-intact family household and the presence of smokers and consumers of alcoholic beverages in the adolescents' environment with smoking and consuming alcoholic beverages in adolescents with unplanned pregnancies.

METHODS

A cross-sectional study was carried out among 785 pregnant adolescents, aged 13-19 years. Data was collected by trained interviewers using a self-administered questionnaire. The association was determined using multivariate logistic regression analysis.

RESULTS

In adolescents with unplanned pregnancies, the prevalence of active smoking was 21.2% and of alcohol consumption, 41.5%. The percentage of smoking at home was 57.4% and alcohol consumption, 77.5%. Approximately, 80.3% of adolescents with unplanned pregnancies had friends who smoked and 90.6% consumed alcoholic beverages. Multivariate logistic regression analysis shows that having friends who smoke or who consume alcoholic beverages is the most important risk factor for substance use in adolescents with unplanned pregnancies. Smoking and alcohol consumption at home are not associated with smoking in adolescents with unplanned pregnancies.

CONCLUSION

Socializing with friends who smoke and/or consume alcoholic beverages constitutes the most important risk factor for substance use among adolescents with unplanned pregnancies.

How Initial Prevalence Moderates Network-based Smoking Change: Estimating Contextual Effects with Stochastic Actor-based Models

We use an empirically grounded simulation model to examine how initial smoking prevalence moderates the effectiveness of potential interventions designed to change adolescent smoking behavior. Our model investigates the differences that result when manipulating peer influence and smoker popularity as intervention levers. We demonstrate how a simulation-based approach allows us to estimate outcomes that arise (1) when intervention effects could plausibly alter peer influence and/or smoker popularity effects and (2) across a sample of schools that match the range of initial conditions of smoking prevalence in U.S. schools. We show how these different initial conditions combined with the exact same intervention effects can produce substantially different outcomes-for example, effects that produce smoking declines in some settings can actually increase smoking in others. We explore the form and magnitude of these differences. Our model also provides a template to evaluate the potential effects of alternative intervention scenarios.

The density of tobacco retailers in home and school environments and relationship with adolescent smoking behaviours in Scotland

BACKGROUND

Neighbourhood retailing of tobacco products has been implicated in affecting smoking prevalence rates. Long-term smoking usually begins in adolescence and tobacco control strategies have often focused on regulating 'child spaces', such as areas in proximity to schools. This cross-sectional study examines the association between adolescent smoking behaviour and tobacco retail outlet density around home and school environments in Scotland.

METHODS

Data detailing the geographic location of every outlet registered to sell tobacco products in Scotland were acquired from the Scottish Tobacco Retailers Register and used to create a retail outlet density measure for every postcode. This measure was joined to individual responses of the Scottish Schools Adolescent Lifestyle and Substance Use Survey (n=20 446). Using logistic regression models, we explored the association between the density of retailers, around both home and school address, and smoking behaviours.

RESULTS

Those living in the areas of highest density of retailers around the home environment had 53% higher odds of reporting having ever smoked (95% CI 1.27 to 1.85, p<0.001) and 47% higher odds of reporting current smoking (95% CI 1.13 to 1.91 p<0.01). Conversely, those attending schools in areas of highest retail density had lower odds of having ever smoked (OR 0.66, 95% CI 0.50 to 0.86 p<0.01) and lower odds of current smoking (OR 0.75, 95% CI 0.59 to 0.95, p<0.05).

CONCLUSIONS

The density of tobacco retail outlets in residential neighbourhoods is associated with increased odds of both ever smoked and current smoking among adolescents in Scotland. Policymakers may be advised to focus on reducing the overall density of tobacco outlets, rather than concentrating on 'child spaces'.

[Social inequalities in adolescent smoking: A cross-national perspective of the role of individual and macro-structural factors]

BACKGROUND

In an EU-funded project, we examined on the basis of international comparative analyses which factors were associated with and contributed to socioeconomic inequalities in adolescent smoking. This paper presents the results obtained and discusses their implications for policy and research.

METHODS

Analyses were based on the "Health Behaviour in School-aged Children (HBSC)" study in 2006 and included more than 50,000 adolescents from 37 countries. The focus was on the association between family affluence and weekly smoking (regularly, at least once a week) among adolescents. Explanatory variables at the individual level refer to psychosocial resources and burdens of school, family, and peers. At the country level, national income, various tobacco control policies, and an index of external differentiation of the educational system were used.

RESULTS

The psychosocial factors of school and family explained many of the inequalities in the smoking behavior of adolescents. In an international comparison, socioeconomic inequalities in smoking were stronger in richer countries. Absolute smoking rates were lower and inequalities in smoking smaller for boys in countries with higher tobacco prices. On the other hand, educational systems with higher degrees of external differentiation showed lower inequalities in smoking beahviour by girls, and relatively higher rates of smoking (for boys and girls). Stronger inequalities in smoking behaviour were demonstrated in countries with a greater range of preventative measures for tobacco dependence (for boys) and with higher levels of government spending on tobacco control (for girls).

CONCLUSION

Experiences in richer countries revealed that tobacco control needs to be strengthened for socially disadvantaged adolescents. The reduction of smoking prevalence and socioeconomic inequalities in smoking behavior should be based not only on a strengthening of psychosocial resources in the family and at school, but also on an increase in tobacco prices.

Smoking Cessation Failure Among Korean Adolescents

The aim of this study was to identify smoking cessation failure subgroups among Korean adolescents. Participants were 379 smoking adolescents who joined a smoking cessation program. A questionnaire and a cotinine urine test were administered before the program began. Three months after the program ended, the cotinine urine test was repeated. A decision-tree model identified seven subgroups with low or high smoking cessation rates. The predictors of smoking cessation were intention to stop smoking, initiation of smoking, amount of cigarette use, self-efficacy, and paternal smoking status. The subgroup with the lowest smoking cessation rate included adolescents who did not have any intention to stop smoking and who had started smoking after eighth grade, and none of the participants in this group stopped smoking. The results of this study provide crucial information for tailored smoking cessation programs.

US adolescents' friendship networks and health risk behaviors: a systematic review of studies using social network analysis and Add Health data

Background. Documented trends in health-related risk behaviors among US adolescents have remained high over time. Studies indicate relationships among mutual friends are a major influence on adolescents' risky behaviors. Social Network Analysis (SNA) can help understand friendship ties affecting individual adolescents' engagement in these behaviors. Moreover, a systematic literature review can synthesize findings from a range of studies using SNA, as well as assess these studies' methodological quality. Review findings also can help health educators and promoters develop more effective programs. Objective. This review systematically examined studies of the influence of friendship networks on adolescents' risk behaviors, which utilized SNA and the Add Health data (a nationally representative sample). Methods. We employed the Matrix Method to synthesize and evaluate 15 published studies that met our inclusion and exclusion criteria, retrieved from the Add Health website and 3 major databases (Medline, Eric, and PsycINFO). Moreover, we assigned each study a methodological quality score (MQS). Results. In all studies, friendship networks among adolescents promoted their risky behaviors, including drinking alcohol, smoking, sexual intercourse, and marijuana use. The average MQS was 4.6, an indicator of methodological rigor (scale: 1-9). Conclusion. Better understanding of risky behaviors influenced by friends can be useful for health educators and promoters, as programs targeting friendships might be more effective. Additionally, the overall MQ of these reviewed studies was good, as average scores fell above the scale's mid-point.

Alcohol use among adolescent youth: the role of friendship networks and family factors in multiple school studies

To explore the co-evolution of friendship tie choice and alcohol use behavior among 1,284 adolescents from 12 small schools and 976 adolescents from one big school sampled in the National Longitudinal Study of Adolescent to Adult Health (AddHealth), we apply a Stochastic Actor-Based (SAB) approach implemented in the R-based Simulation Investigation for Empirical Network Analysis (RSiena) package. Our results indicate the salience of both peer selection and peer influence effects for friendship tie choice and adolescent drinking behavior. Concurrently, the main effect models indicate that parental monitoring and the parental home drinking environment affected adolescent alcohol use in the small school sample, and that parental home drinking environment affected adolescent drinking in the large school sample. In the small school sample, we detect an interaction between the parental home drinking environment and choosing friends that drink as they multiplicatively affect friendship tie choice. Our findings suggest that future research should investigate the synergistic effects of both peer and parental influences for adolescent friendship tie choices and drinking behavior. And given the tendency of adolescents to form ties with their friends' friends, and the evidence of local hierarchy in these networks, popular youth who do not drink may be uniquely positioned and uniquely salient as the highest rank of the hierarchy to cause anti-drinking peer influences to diffuse down the social hierarchy to less popular youth. As such, future interventions should harness prosocial peer influences simultaneously with strategies to increase parental support and monitoring among parents to promote affiliation with prosocial peers.

The highs that bind: school context, social status and marijuana use

Substance use has been closely linked with the structural characteristics of adolescent social networks. Those who drink, smoke, and use drugs typically enjoy an elevated status among their peers. Rates of substance use vary substantially across schools, and indicators of school structure and climate account for at least part of this variation. Emerging research suggests peer-group processes are contingent on school context, but questions remain regarding the school-level mechanisms which condition the influence of network characteristics on substance use. The present study uses multilevel logistic regression models to examine the moderating influence of school connectedness, school drug culture, and global network density on the association between peer network status and marijuana use. The analyses draw on self, peer, and parental data from a sample of 7,548 high-school aged youth nested within 106 schools participating in the National Longitudinal Study of Adolescent to Adult Health (mean age = 15.2; % white = 59 %; male = 45 %). The results indicate that school connectedness significantly reduces the effect of social status on marijuana use. This provides evidence that school-level mechanisms can reduce the instrumentality of marijuana consumption in the status attainment process in adolescence.

On social and cognitive influences: relating adolescent networks, generalized expectancies, and adolescent smoking

We examine the moderating role of friendship and school network characteristics in relationships between 1) youths’ friends smoking behavior and youths’ own generalized expectancies regarding risk and future orientation and 2) generalized expectancies of youths’ friends and youths’ own generalized expectancies. We then relate these constructs to smoking. Using a longitudinal sample from the National Longitudinal Study of Adolescent Health (N = 15,142), the relationship between friends’ generalized expectancies and youths’ expectancies is stronger for those more central in the network, with more reachability, or stronger network ties, and weaker for those with denser friendship networks. Risk expectancies exhibited an inverted U shaped relationship with smoking at the next time point, whereas future orientation expectancies displayed a nonlinear accelerating negative relationship. There was also a feedback effect in which smoking behavior led to higher risk expectancies and lower future orientation expectancies in instrumental variable analyses.

Social networks and smoking: exploring the effects of peer influence and smoker popularity through simulations

Adolescent smoking and friendship networks are related in many ways that can amplify smoking prevalence. Understanding and developing interventions within such a complex system requires new analytic approaches. We draw on recent advances in dynamic network modeling to develop a technique that explores the implications of various intervention strategies targeted toward micro-level processes. Our approach begins by estimating a stochastic actor-based model using data from one school in the National Longitudinal Study of Adolescent Health. The model provides estimates of several factors predicting friendship ties and smoking behavior. We then use estimated model parameters to simulate the coevolution of friendship and smoking behavior under potential intervention scenarios. Namely, we manipulate the strength of peer influence on smoking and the popularity of smokers relative to nonsmokers. We measure how these manipulations affect smoking prevalence, smoking initiation, and smoking cessation. Results indicate that both peer influence and smoking-based popularity affect smoking behavior and that their joint effects are nonlinear. This study demonstrates how a simulation-based approach can be used to explore alternative scenarios that may be achievable through intervention efforts and offers new hypotheses about the association between friendship and smoking.

With a Little Help from My Friends? Asymmetrical Social Influence on Adolescent Smoking Initiation and Cessation

This study investigates whether peer influence on smoking among adolescents is asymmetrical. We hypothesize that several features of smoking lead peers to have a stronger effect on smoking initiation than cessation. Using data from the National Longitudinal Study of Adolescent Health we estimate a dynamic network model that includes separate effects for increases versus decreases in smoking, while also controlling for endogenous network change. We find that the impact of peer influence is stronger for the initiation of smoking than smoking cessation. Adolescents rarely initiate smoking without peer influence but will cease smoking while their friends continue smoking. We discuss the implications of these results for theories of peer influence and health policy.

Unplanned pregnancy in adolescents: association with family structure, employed mother, and female friends with health-risk habits and behaviors

Previous publications have suggested that living in a nonintact family household and socializing with girlfriends who smoke or who consume alcoholic beverages favor the development of health-risk habits and customs in adolescents. However, their relationship with unplanned pregnancy in adolescents has not been determined. We investigated the association between family structure, employed mother, and female friends with health-risk habits and behaviors with unplanned pregnancy in adolescents (n = 3,130). After adjusting for low maternal educational level and low family income, logistic regression analyses showed that having an employed mother and socializing with girlfriends who have health-risk habits or behaviors, rather than living in a nonintact family household, appear to be the most important health-risk factors for unplanned pregnancy in adolescents. It is important for health-care programs for adolescents to be revised and for their strategies be strengthened in order to reach the objectives for which they were created.

Disposable income with tobacco smoking among young adolescents: a multilevel analysis

PURPOSE

Prior studies examining the connection between disposable income and adolescent smoking often yielded mixed results, partly due to the lack of consideration for contextual variables. In the present study, we sought to broaden understanding of disposable income on adolescent smoking behaviors via both absolute and relative perspectives in the school context.

METHODS

We obtained data from the 2010 Global Youth Tobacco Survey (GYTS) in Taiwan. Information concerning sociodemographics, disposable income, smoking history, and contextual smoking exposure (e.g., school) were assessed via self-report. Recent-onset smokers were defined as those who had their first cigarette within two years of the survey. Complex survey and multilevel analyses were carried out to estimate association.

RESULTS

Adolescents with higher monthly disposable income were 2∼5 times more likely to start smoking and become regular smokers. Having the least disposable income in a class appeared linked with increased risk of tobacco initiation by 40% (95% confidence interval [CI]: 2%-91%). Pupils' odds to start smoking were lowered to .70 when the majority of schoolmates had low disposable income (95% CI: .51-.99).

CONCLUSIONS

Adolescent risk of smoking initiation may be differentially affected by individual- and contextual-level absolute and relative disposable income. Future research is needed to delineate possible mechanisms underlying unfavorable health behaviors associated with disposable incomes in early adolescence.

Social integration in friendship networks: the synergy of network structure and peer influence in relation to cigarette smoking among high risk adolescents

Using data from a study of high risk adolescents in Southern California, U.S.A. (N=851), this study examined synergy between social network measures of social integration and peer influence in relation to past month cigarette smoking. Using Hierarchical Linear Modeling, results indicated that being central in networks was significantly and positively related to past month cigarette smoking, across all study models. In addition, there is modest evidence that the number of reciprocated friendship ties was positively related to past month cigarette smoking. There is also some modest evidence that the relationship between having reciprocated friendships and past month cigarette smoking was moderated by a network peer influence process, smoking with those in youths' best friend networks. Findings indicate that being integrated within a social network context of peer influences favoring drug use relates to more smoking among these high risk youth.

A dynamic model of US adolescents' smoking and friendship networks

OBJECTIVES

We investigated the associations between smoking and friend selection in the social networks of US adolescents.

METHODS

We used a stochastic actor-based model to simultaneously test the effects of friendship networks on smoking and several ways that smoking can affect the friend selection process. Data are from 509 US high school students in the National Longitudinal Study of Adolescent Health, 1994-1996 (46.6% female, mean age at outset=15.4 years).

RESULTS

Over time, adolescents' smoking became more similar to their friends. Smoking also affected who adolescents selected as friends; adolescents were more likely to select friends whose smoking level was similar to their own, and smoking enhanced popularity such that smokers were more likely to be named as friends than were nonsmokers, after controlling for other friend selection processes.

CONCLUSIONS

Both friend selection and peer influence are associated with smoking frequency. Interventions to reduce adolescent smoking would benefit by focusing on selection and influence mechanisms.

Systems science methods in public health: dynamics, networks, and agents

Complex systems abound in public health. Complex systems are made up of heterogeneous elements that interact with one another, have emergent properties that are not explained by understanding the individual elements of the system, persist over time, and adapt to changing circumstances. Public health is starting to use results from systems science studies to shape practice and policy, for example in preparing for global pandemics. However, systems science study designs and analytic methods remain underutilized and are not widely featured in public health curricula or training. In this review we present an argument for the utility of systems science methods in public health, introduce three important systems science methods (system dynamics, network analysis, and agent-based modeling), and provide three case studies in which these methods have been used to answer important public health science questions in the areas of infectious disease, tobacco control, and obesity.

Systematic review of social network analysis in adolescent cigarette smoking behavior

BACKGROUND

Social networks are important in adolescent smoking behavior. Previous research indicates that peer context is a major causal factor of adolescent smoking behavior. To date, however, little is known about the influence of peer group structure on adolescent smoking behavior.

METHODS

Studies that examined adolescent social networks with regard to their cigarette smoking behavior were identified through online and manual literature searches. Ten social network analysis studies involving a total of 28,263 adolescents were included in the final review.

RESULTS

Of the 10 reviewed studies, 6 identify clique members, liaisons, and isolates as contributing factors to adolescent cigarette smoking. Significantly higher rates of smoking are noted among isolates than clique members or liaisons in terms of peer network structure. Eight of the reviewed studies indicate that peer selection or influence precedes adolescents' smoking behavior and intent to smoke. Such peer selection or influence accounts for a large portion of similarities among smoking adolescents.

CONCLUSION

Adolescents who are identified as isolates are more likely to smoke and engage in risk-taking behaviors than others in the peer network structure. Given that the vast majority of current adult smokers started their smoking habits during adolescence, adolescent smoking prevention efforts will likely benefit from incorporating social network analytic approaches and focusing the efforts on isolates and other vulnerable adolescents from a peer selection and influence perspective.

Smoking in non-student Mexican adolescents with asthma: relation with family structure, educational level, parental approval of smoking, parents who smoke, and smoking friends

INTRODUCTION

The association between some factors of the familial and social environment with smoking in non-student adolescents with asthma has not been explored. The aim of the study was to determine the association between family structure, educational level, parental approval of smoking, parents who smoke, and smoking friends with smoking in non-student adolescents with asthma.

SUBJECTS AND METHODS

In a cross-sectional study, data were obtained by means of a structured questionnaire applied to 4,778 non-student adolescents aged 13-18 years. Diagnosis of asthma was performed using a questionnaire based on the International Study of Asthma and Allergy in Childhood questionnaire. The smoking habit was determined by application of a self-administered questionnaire. Odds ratios (OR) were determined for smoking using logistic regression.

RESULTS

From the total sample, asthma prevalence was 6.6% and of active smoking, 34.2%. Age at initiation of asthma symptoms was 5.15±3.52 years, and that of active smoking was 13.65±2.07 years. Percentage of non-intact family (40.1 vs. 32.7%) was greater in the group of adolescents with asthma. Logistic regression models show that parental approval of smoking (adjusted OR=5.57; 95% confidence interval=2.48-12.51) and smoking friends (adjusted OR=2.92; 95% confidence interval=1.04-8.19) are associated with smoking in non-student adolescents with asthma.

CONCLUSION

In this study, parental approval of smoking and having friends who smoke appear to be associated with smoking among non-student adolescents with asthma.