School bullying and susceptibility to smoking among never-tried cigarette smoking students

School bullying and susceptibility to smoking among never-tried cigarette smoking students

Preventive Medicine 85 (2016) 69–73 Contents lists available at ScienceDirect Preventive Medicine journal homepage: www.elsevier.com/locate/ypmed S...

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Preventive Medicine 85 (2016) 69–73

Contents lists available at ScienceDirect

Preventive Medicine journal homepage: www.elsevier.com/locate/ypmed

School bullying and susceptibility to smoking among never-tried cigarette smoking students Sunday Azagba ⁎ Propel Centre for Population Health Impact, University of Waterloo, Waterloo, Ontario, Canada School of Public Health and Health Systems, University of Waterloo, Waterloo, Ontario, Canada

a r t i c l e

i n f o

Available online 23 January 2016 Keywords: Smoking susceptibility Adolescent health Never-smoking adolescents School bullying Bullying involvement

a b s t r a c t Introduction. Bullying involvement has been linked with substance use; however, less is known about its relationship with pre-initiation stages of adolescent cigarette smoking behavior. This study examined the association between bullying involvement and smoking susceptibility among never tried or experimented with cigarette smoking students. Susceptibility to cigarette smoking in adolescence is a strong predictor of subsequent smoking initiation. Methods. A cross-sectional data on Canadian adolescent and youth were drawn from the 2012/2013 Youth Smoking Survey (n = 28,843). Logistic regression analysis was used to examine the association between bullying and smoking susceptibility among never-smoking students. Results. About 21% self-reported involvement in bullying (as a bully, victim or both). Middle school students (grades 6–8) reported more involvement in bullying (24%) than those in grades 9–12 (16%). The multivariable analyses showed that the association between bullying and smoking susceptibility was significantly different by grade level. Middle school students involved in bullying had higher odds of smoking susceptibility compared to uninvolved students (bully, adjusted odds ratio [AOR] = 2.54, 95% CI = 1.73–3.74; victim, AOR = 1.29, 95% CI = 1.11–1.48; bully–victim, AOR = 2.19, 95% CI = 1.75–2.74). There were no significant associations between all subgroups of bullying and smoking susceptibility for grades 9–12 students. Conclusions. Students involved in bullying were more susceptible to smoking, although patterns of association varied by grade level. In particular, the findings highlight that non-smoking middle school students involved in bullying were susceptible to future smoking. © 2016 Elsevier Inc. All rights reserved.

Introduction The school environment remains a critical influence on adolescent development and well-being. There is a concern among parents, health professionals, educators, and school authorities about bullying at school, particularly given that bullying can be a major stressor that shapes adolescent's health (Newman et al., 2005; Arseneault et al., 2006; Gini and Pozzoli, 2009; Swearer et al., 2010; Srabstein and Leventhal, 2010; Carrera et al., 2011; Hong and Espelage, 2012; Phillips, 2007; Olweus, 2013). According to the World Health Organization (WHO), bullying is defined as a violent behavior that involves “the intentional use of physical force or power, threatened or actual, against oneself, another person, or against a group or community, which either results in or has a high likelihood of resulting in injury, death, psychological harm, mal-development or deprivation” (WHO, 2002). Bullying often occurs ⁎ Propel Centre for Population Health Impact, Faculty of Applied Health Sciences, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1. Fax: +1 519 746 8171 E-mail address: [email protected].

http://dx.doi.org/10.1016/j.ypmed.2016.01.006 0091-7435/© 2016 Elsevier Inc. All rights reserved.

when an imbalance of power exists between the perpetrators (bullies) and the victims (Olweus, 2013). One area of focus that has received a considerable level of attention is the relationship between bullying and tobacco use among adolescents and youths, with results showing mixed findings (Hong et al., 2014). A number of studies point to a significant association between bullying and cigarette smoking; those involved in bullying were more likely to engage in tobacco use (Alikasifoglu et al., 2007; Bradshaw et al., 2013; Vieno et al., 2011; Niemelä et al., 2011; Luukkonen et al., 2010; Weiss et al., 2011; Tharp-Taylor et al., 2009; Radliff et al., 2012). For example, evidence from the Health Behavior in School Survey showed that bullying behavior was significantly associated with the use of cigarettes among Italian adolescents (Vieno et al., 2011). In a prospective study among Finnish males, Niemelä et al. (2011) found that those who were victimized at age 8 were more likely to be heavy smokers (defined as smoking at least 10 cigarettes a day) at age 18. Some studies have equally reported no significant association between substance use and bullying, at least for some forms of bullying (Alikasifoglu et al., 2007; Kelly et al., 2015a, 2015b; Liang et al., 2007; Moore et al., 2014; Rivers et al., 2009). In a sample of year 7–9 Australian students, Kelly et al.

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(2015a) found that bully–victims and bullies were more likely to use tobacco, while no significant association was found for victims. While the preponderance of evidence from the extant literature suggests a link between bullying and tobacco use, much of this work has focused on those that have already initiated smoking. However, tobacco use is a learned behavior that evolves through several phases, including precontemplation, preparation or contemplation, experimentation, initiation, regular smoking, and addiction (Mayhew et al., 2000; Stern et al., 1987; Jackson, 1998). The preparation or contemplation phase is when adolescents show signs of vulnerability to smoking, it is a period when there is heightened potential to internalize beliefs and norms about smoking (Mayhew et al., 2000; Stern et al., 1987; Jackson, 1998). Tobacco use remains one of the leading causes of preventable death worldwide, with studies showing that adolescence is a critical period during which smoking initiation occurs, and early initiation may make it harder to quit smoking as a result of developing severe addiction to nicotine (DiFranza et al., 2007; Azagba et al., 2015; Johnston et al., 2012). To further our understanding of the relationship between bullying and smoking, it is important to consider never-smoking adolescents. The main objective of this study was to examine the association between involvement in bullying and susceptibility to smoking among those that never tried or experimented with cigarette smoking. The secondary objective was to examine whether the association between bullying involvement and susceptibility varies by grade level given that some studies have reported a higher prevalence of bullying at school among middle school students (Nansel et al., 2001; Radliff et al., 2012). Susceptibility to smoking, defined as the lack of a firm decision not to engage in smoking in the future (Pierce et al., 1996), has been shown to be an important indicator of vulnerability to future cigarette use (Choi et al., 2001; Forrester et al., 2007; Jackson, 1998).

other students in the last 30 days (to assess bully or perpetrator). Responses were categorized as involvement in bullying (any) versus uninvolved (never). In addition, four categories of bullying were derived since a dichotomous classification may mask important characteristics of bullying subgroups (Nansel et al., 2001; Kelly et al., 2015a). Combining the two indicators of involvement in bullying, four subgroups of bullying were derived: bully, victim, bully–victim (both as a bully and victim), and uninvolved (neither bully nor victim). A number of covariates were included in the analysis that have been shown to be associated with smoking susceptibility in previous studies (e.g., Centers for Disease Control and Prevention, 2007; Seo et al., 2008; Veeranki et al., 2014; Wilkinson et al., 2008): school grade levels (7 to 12 and 6 as the reference category), gender (male = 1, female = 0); home smoking rules (complete smoking ban versus non or partial ban); exposure to secondhand smoke (SHS) in a car in the last 7 days (SHS exposure, did not ride in a car, and nonSHS exposure—reference group); whether parent or guardian smoke (yes versus no); whether sibling(s) smoke (yes versus no); whether friends smoke (yes versus no); and region of residence—East (Newfoundland and Labrador, Prince Edward Island, New Brunswick, and Nova Scotia), West (Saskatchewan, Alberta, and British Columbia), Quebec, and Ontario (reference category). Analysis Logistic regression was used to examine the association between involvement in bullying and susceptibility to smoking among never-smoking adolescents in grades 6 to 12. The multivariable analyses adjusted for gender, grade levels, region of residence, and smoking-related exposure, including peer smoking status. Analyses were also examined by grade levels, with separate analysis done for students in grades 6–8 and 9–12. Unadjusted (OR) and adjusted odds ratios (AOR) and 95% confidence intervals (CI) were reported. All regression results and descriptive analyses are population weighted using the survey weights to produce population estimates and adjust for unequal probabilities of selection, with standard errors clustered at the school level. All analyses were carried out using Stata 14.0 (Stata Corp, College Station, Texas).

Methods

Results Data This study used a cross-sectional population sample from the 2012/2013 Youth Smoking Survey (YSS). A detailed description of the design and procedure of the YSS has been documented elsewhere (Elton-Marshall et al., 2011). Briefly, the YSS is a nationally representative, school-based sample of Canadian students in grades 6 to 12 that primarily collects information about adolescents' tobacco use as well as corresponding demographic variables. The survey excludes those living on First Nations reserves, Canada's three northern Territories (Yukon, Nunavut, and Northwest Territories), and those attending special schools or schools on military bases. The province of Manitoba did not participate in the 2012/2013 YSS cycle. The average school participation rate of 2012/2013 was 64%, with about 72% of students completing the paper-andpencil questionnaires. YSS received ethics approval from the University of Waterloo Human Research Ethics Committee, Health Canada's Research Ethics Board, and the provincial ethics review boards affiliated with the institutions of provincial consortium members. In addition, some school boards ethics review committees also reviewed and approved the YSS project. Measures Dependent variable Susceptibility to smoking among those that never tried or experimented with cigarette smoking was assessed by asking students the following questions based on Pierce et al. (1996) algorithm: “Do you think in the future you might try smoking cigarettes?” “If one of your best friends was to offer you cigarette would you smoke it?” “At any time in the next year do you think you will smoke a cigarette?” Answers to each of these three questions have four options: (i) definitely yes, (ii) probably yes, (iii) probably not, and (iv) definitely not. Students who answered “definitely not” to all three questions were considered non-susceptible to smoking; otherwise, students were considered susceptible. Independent variables The main independent variable of interest, involvement in bullying—as either a bully or a victim—was assessed from two questions: if they were bullied by other students in the last 30 days (to assess victimization), and if they bullied

The weighted sample characteristics of the study sample are reported in Table 1. Of the 28,843 never-smoking students in grades 6–12, 28% were susceptible to smoking, 72% were non-susceptible to smoking, and there were slightly more females (51%) than males (49%). About 30% had a smoking parent or guardian and 15% reported having a smoking friend. Approximately 21% self-reported involvement in bullying (as a bully, victim, or both) in the last 30 days. A higher proportion of students were classified as a victim (13%) compared to bully–victim (5%) and bully (3%). More students in grades 6–8 reported some involvement in bullying (24%) than those in grades 9–12 (16%). The proportion of students classified as victims was equally higher among grades 6–8 students (16%) compared to students in grades 9–12 (10%). The results from the unadjusted logistic regression, reported in Table 2, showed a statistically significant association between involvement in bullying and susceptibility to smoking among never-smoking students in grades 6 to 12. In particular, students involved in bullying had higher odds of being susceptible to smoking than those uninvolved in bullying (OR = 1.48, 95% CI = 1.32–1.67). Analyses examining the association between bullying involvement and smoking susceptibility by grade level also showed statistically significant results. Among never-smoking students in grades 6–8, bullying was significantly associated with smoking susceptibility (OR = 1.78, 95% CI = 1.56–2.02). Likewise, for those in grades 9–12, bullying involvement was associated with higher odds of smoking susceptibility (OR = 1.22, 95% CI = 1.04– 1.43). In the bullying involvement classification analyses, bullies (OR = 1.93, 95% CI = 1.42–2.63), victims (OR = 1.31, 95% CI = 1.14–1.50), and bully–victims (OR = 1.75, 95% CI = 1.43–2.15) were more likely to be susceptible to smoking than uninvolved students. Similar significant results were found for those in grades 6–8 (bullies, OR = 3.12, 95% CI = 2.21–4.42; victims, OR = 1.43, 95% CI = 1.25–1.64; bully–victims, OR = 2.48, 95% CI = 1.99–3.09) while those in grades 9–12 were not significant.

S. Azagba / Preventive Medicine 85 (2016) 69–73 Table 1 Weighted sample characteristics (%).

Susceptibility to smoking Non-susceptible Bullying role Victim only Bully only Bully–victim Uninvolved Sex Male Female Grade level 6 7 8 9 10 11 12 Smoking-related exposure Home smoking restrictions Non/partial home smoking restrictions Parent/guardian smokes No parent/guardian smokes Sibling smokes No sibling smokes Friend smokes No friend smokes SHS in a car Did not ride in a car No SHS in a car

Grades 6–8

Grades 9–12

Overall sample

(n = 14,209)

(n = 14,634)

(n = 28,843)

28 72

29 71

28 72

16 3 5 76

10 3 5 82

13 3 5 79

49 51

49 51

49 51

29 26 25 20

15 16 16 15 14 13 11

14 86

13 87

14 86

30 70 6 94 6 94 11 12 77

30 70 10 90 23 77 14 10 76

30 70 8 92 15 85 13 11 76

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Table 3 Multivariable logistic regression of the association between any involvement in bullying and smoking susceptibility.

Involved in bullying

32 34 34

Uninvolved Sex Male Female Grade level 6 7 8 9 10 11 12

The results of the multivariable analyses are reported in Table 3 (for any bullying involvement) and Table 4 (bullying categories). In Table 3, bullying involvement was significantly associated with smoking susceptibility, with those involved in bullying more likely to be susceptible to smoking (OR = 1.29, 95% CI = 1.15–1.45). Analyses by grade levels revealed differences in the association between bullying and smoking susceptibility for those in grades 6–8 and 9–12. Among never-smoking students in grades 6–8, bullying was significantly associated with smoking susceptibility (OR = 1.58, 95% CI = 1.38–1.81) while no significant association was found for those in grades 9–12 (OR = 1.02, 95% CI = 0.88–1.19). In terms of the other covariates included in the analyses, smoking-related exposure was significantly associated with susceptibility to smoking. As expected, higher likelihood of smoking susceptibility was found for those with a smoking

Smoking-related exposure Parent/guardian smokes No parent/guardian smokes Friend smokes No friend smokes Sibling smokes No sibling smokes Home smoking restrictions Non/partial home smoking restrictions SHS in a car Did not ride in a car No SHS in a car Region East West Quebec Ontario Observations

Overall sample

Grades 6–8

Grades 9–12

AOR (95% CI)

AOR (95% CI)

AOR (95% CI)

1.29 (1.15–1.45) 1

1.58 (1.38–1.81) 1

1.02 (0.88–1.19) 1

0.95 (0.86–1.06) 1

1.13 (1.00–1.27) 1

0.83 (0.73–0.96) 1

1 1.29 (1.12–1.49) 1.46 (1.26–1.69) 1.35 (1.12–1.63) 1.32 (1.09–1.60) 0.93 (0.78–1.11) 0.79 (0.67–0.93)

1 1.28 (1.10–1.49) 1.45 (1.24–1.69)

1.31 (1.17–1.47) 1 2.03 (1.83–2.24) 1 1.35 (1.20–1.52) 1 1.40 (1.22–1.61) 1

1.46 (1.19–1.78) 1 2.77 (2.35–3.27) 1 1.56 (1.27–1.92) 1 1.57 (1.31–1.88) 1

1.20 (1.05–1.36) 1 1.91 (1.68–2.17) 1 1.26 (1.10–1.45) 1 1.24 (1.01–1.52) 1

1.34 (1.19–1.52) 0.90 (0.80–1.01) 1

1.48 (1.23–1.78) 0.84 (0.72–0.97) 1

1.27 (1.08–1.50) 0.96 (0.79–1.17) 1

0.82 (0.71–0.95) 0.93 (0.81–1.06) 0.77 (0.62–0.95) 1 28,843

0.76 (0.63–0.91) 0.91 (0.78–1.05) 0.75 (0.62–0.91) 1 14,209

0.87 (0.71–1.08) 0.94 (0.76–1.16) 0.77 (0.52–1.12) 1 14,634

1 0.96 (0.83–1.11) 0.68 (0.57–0.82) 0.58 (0.45–0.73)

AOR = adjusted odds ratios. Table 2 Logistic regression of the association between bullying and smoking susceptibility.

Any bullying involvement Involved in bullying Uninvolved Bullying categories Bully only Victim only Bully–victim Uninvolved Observations OR = unadjusted odds ratios.

Overall sample

Grades 6–8

Grades 9–12

OR (95% CI)

OR (95% CI)

OR (95% CI)

1.48 (1.32–1.67) 1

1.78 (1.56–2.02) 1

1.22 (1.04–1.43)

Table 4 Multivariable logistic regression of the association between bullying and smoking susceptibility. Overall sample

Bully only 1.93 (1.42–2.63) 1.31 (1.14–1.50) 1.75 (1.43–2.15) 1 28,843

3.12 (2.21–4.42) 1.43 (1.25–1.64) 2.48 (1.99–3.09) 1 14,209

1.25 (0.77–2.01) 1.21 (0.95–1.55) 1.23 (0.91–1.66) 1 14,634

Victim only Bully–victim Uninvolved Observations

Grades 6–8

Grades 9–12

AOR (95% CI)

AOR (95% CI)

AOR (95% CI)

1.62 (1.20–2.18) 1.14 (0.99–1.30) 1.55 (1.27–1.88) 1 28,843

2.54 (1.73–3.74) 1.29 (1.11–1.48) 2.19 (1.75–2.74) 1 14,209

1.08 (0.70–1.64) 0.98 (0.77–1.26) 1.09 (0.83–1.43) 1 14,634

AOR = adjusted odds ratios. Analyses adjusted for sex, grade level, smoking-related exposures, and region of residence.

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family member (parent or guardian and sibling), with a friend who smokes, with no home smoking ban, and those exposed to SHS in cars. Adolescents in higher-grade levels (grades 7–10) had higher odds of being susceptible to smoking compared to grade 6 students. Students classified as bullies (Table 4) were more likely to be susceptible to smoking compared to those uninvolved in bullying (OR = 1.62, 95% CI = 1.20–2.18). Likewise, the bully–victim students had higher odds of being susceptible to smoking than uninvolved students (OR = 1.55, 95% CI = 1.27–1.88). There were no significant differences in susceptibility to smoking between the victim group and uninvolved students (OR = 1.14, 95% CI = 0.99–1.30). In the stratified analyses by grade, all subgroups of bullying had higher odds of smoking susceptibility (bully, OR = 2.54, 95% CI = 1.73–3.74; victim, OR = 1.29, 95% CI = 1.11–1.48; bully–victim, OR = 2.19, 95% CI = 1.75–2.74) for grades 6–8 students. Conversely, there were no significant associations between all subgroups of bullying and smoking susceptibility for those in grades 9–12. Discussion The extant literature suggests that bullying may be a precursor for a range of negative developmental and health outcomes, including substance use (Copeland et al., 2013; Hong et al., 2014; Gini and Pozzoli, 2009; Valdebenito et al., 2015; Hong and Espelage, 2012; Ttofi et al., 2012). There are inconsistent findings from the limited number of studies that have examined the relationship between bullying and tobacco use, with the majority of studies focusing on those that have already initiated smoking (Moore et al., 2014; Kelly et al., 2015a, 2015b; Vieno et al., 2011, Niemelä et al., 2011; Radliff et al., 2012). The current study extends previous research by examining the association between school bullying and smoking susceptibility among never-smoking (i.e., never tried or experimented with cigarette smoking) students in grades 6–12. Among never-smoking adolescents, about one in five self-reported involvement in bullying (as a bully, victim, or both) in the last 30 days. More students in grades 6–8 reported some involvement in bullying (24%) than those in grades 9–12 (16%). For those in grades 6–8 (mainly aged 11–14), 16% were classified as victims, 3% as bullies, and 5% as bully–victims. This is consistent with a recent Australian study among secondary school students (aged 12–15), which found 18% as victims, 3% as bullies, and 5% as bully–victims (Kelly et al., 2015a). Higher levels of victimization among middle school students have been reported elsewhere (Nansel et al., 2001; Alikasifoglu et al., 2007; Radliff et al., 2012). The multivariable analyses revealed that involvement in bullying is strongly associated with smoking susceptibility among never-smoking adolescents. The findings that bullies and bully–victims were more likely to be susceptible to smoking are consistent with a growing evidence showing that these subgroups may have heightened risks of problem behaviors (Alikasifoglu et al., 2007; Bradshaw et al., 2013; Radliff et al., 2012; Vieno et al., 2011; Kelly et al., 2015a). The results shown here may partly be attributed to the role social context plays in smoking initiation, especially among adolescents and youths (Mayhew et al., 2000). One possible rationale for this is the homophily hypothesis, where peer relationship is shaped by shared characteristics (Espelage et al., 2003). Homophily theory support the notion that adolescents' bullying behaviors and attitudes could result from selection (peer relationship based on prior similar traits) and socialization processes (peer influence over time irrespective of prior traits) (Kandel, 1978). Among middle school students in grades 6–8, Espelage et al. (2003) found evidence of peer group contextual influences on individual-level bullying behavior. General strain theory of crime and delinquency offers another conceptual framework to support why victims and bully–victims may have an increased risk of substance use than non-victimized adolescents (Agnew, 1992, 2001; Hay and Evans, 2006). At the same time, the lack of significant differences in smoking susceptibility between victims

and those uninvolved in bullying could be a result of victims being less likely to be involved in a social setting. Prior research has shown that victims of bullying were more socially isolated and had more difficulty making friends (Alikasifoglu et al., 2007; Nansel et al., 2001; Spriggs et al., 2007; Smith et al., 2004). The association between bullying and smoking susceptibility was significantly different by grade level, with middle school students involved in bullying more at a higher likelihood of being susceptible to smoking. There were statistically significant differences in smoking susceptibility between victims and non-involved peers, though stronger associations were found for bullies and bully–victims. This is somewhat consistent with a previous study that found a significant relationship between involvement in bullying and cigarette use among middle school students (Radliff et al., 2012). However, Radliff and colleagues did not find a significant relationship between middle school victims and cigarette use. Furthermore, while the current study found no association between high school student involvement in bullying and smoking susceptibility, Radliff et al. (2012) found a higher cigarette use among high school students involved in bullying. One possible explanation for the differences in the findings in both studies may be due to the different outcome variables analyzed, with the current study focusing on vulnerability to future smoking. As discussed, the decision to initiate or start smoking is not as easy as a binary choice (yes versus no), it is more likely to involve a process or sequence of stages (Mayhew et al., 2000; Stern et al., 1987). Therefore, identifying the characteristics of those with a higher propensity to initiate smoking is beneficial for prevention targeting and public health. The present study has some limitations that are worth noting. First, this study is based on self-reported measures, including school bullying and thus are subject to recall bias. Second, there is no measure of the severity or frequency of bullying in YSS data. Therefore, the current study did not examine the frequency of school bullying. Hopefully, Health Canada will consider including questions that capture frequency of bullying in future YSS (now known as the Canadian Student Tobacco, Alcohol and Drugs Survey—CSTADS). Third, the results shown here make no claim of causality concerning bullying involvement and susceptibility of smoking. Future studies should consider replicating this study using longitudinal data. Finally, other potential confounders (mental health status, socioeconomic status) were not available in YSS. These limitations notwithstanding, using a large and nationally representative data of Canadian adolescent school students, the findings of the current study provide further insight into the relationship between school bullying and smoking. In particular, showing that neversmoking middle school students involved in bullying may have an increased risk of future smoking initiation. Bullying prevention programs can be patterned along demographic differences, including bullying subtypes. For example, early intervention programs targeting younger students that include appropriate coping and resilience skills may provide both short- and long-term health benefits given that bullying during childhood may have effects that persist into adulthood (Copeland et al., 2013; Ttofi et al., 2011a, 2011b, 2012; Jiang et al., 2011). Additionally, prevention and control programs could be enhanced by addressing the broad range of problem behaviors associated with bullying involvement (Bradshaw et al., 2013; Guerra and Bradshaw, 2008). Conflict of interest The authors declare that there are no conflicts of interests. Acknowledgment This work was supported by a research grant from the Canadian Cancer Society Research Institute (CCSRI) (grant number 2011701019) to Propel Centre for Population Health Impact, University of Waterloo.

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References Agnew, R., 1992. Foundation for a generalism strain theory of crime and delinquency. Criminology 30, 47. Agnew, R., 2001. Building on the foundation of general strain theory: specifying the types of strain most likely to lead to crime and delinquency. J. Res. Crime Delinq. 38 (4), 319–361. Alikasifoglu, M., Erginoz, E., Ercan, O., Uysal, O., Albayrak-Kaymak, D., 2007. Bullying behaviours and psychosocial health: results from a cross-sectional survey among high school students in Istanbul, Turkey. Eur. J. Pediatr. 166 (12), 1253–1260. Arseneault, L., Walsh, E., Trzesniewski, K., Newcombe, R., Caspi, A., Moffitt, T.E., 2006. Bullying victimization uniquely contributes to adjustment problems in young children: a nationally representative cohort study. Pediatrics 118 (1), 130–138. Azagba, S., Baskerville, N.B., Minaker, L., 2015. A comparison of adolescent smoking initiation measures on predicting future smoking behavior. Prev. Med. Rep. 2, 174–177. Bradshaw, C.P., Waasdorp, T.E., Goldweber, A., Johnson, S.L., 2013. Bullies, gangs, drugs, and school: understanding the overlap and the role of ethnicity and urbanicity. J. Youth Adolesc. 42 (2), 220–234. Carrera, M.V., DePalma, R., Lameiras, M., 2011. Toward a more comprehensive understanding of bullying in school settings. Educ. Psychol. Rev. 23 (4), 479–499. Centers for Disease Control and Prevention, 2007. Exposure to secondhand smoke among students aged 13–15 years–worldwide, 2000–2007. MMWR Morb. Mortal. Wkly Rep. 56 (20), 497. Choi, W.S., Gilpin, E.A., Farkas, A.J., Pierce, J.P., 2001. Determining the probability of future smoking among adolescents. Addiction 96, 313–323. http://dx.doi.org/10.1046/ j. 1360-0443.2001.96231315.x. Copeland, W.E., Wolke, D., Angold, A., Costello, E.J., 2013. Adult psychiatric outcomes of bullying and being bullied by peers in childhood and adolescence. JAMA Psychiatry 70 (4), 419–426. DiFranza, J.R., Savageau, J.A., Fletcher, K., et al., 2007. Symptoms of tobacco dependence after brief intermittent use: the Development and Assessment of Nicotine Dependence In Youth-2 Study. Arch. Pediatr. Adolesc. Med. 161 (7), 704–710. Espelage, D.L., Holt, M.K., Henkel, R.R., 2003. Examination of peer-group contextual effects on aggression during early adolescence. Child Dev. 205–220. Elton-Marshall, T., Leatherdale, S.T., Manske, S.R., Wong, K., Ahmed, R., Burkhalter, R., 2011. Research methods of the Youth Smoking Survey (YSS). Chronic Dis. Inj. Can. 32 (1), 47–54. Forrester, K.K., Biglan, A., Severson, H., Smolkowski, K., 2007. Predictors of smoking onset over two years. Nicotine Tob. Res. 9, 1259–1267. http://dx.doi.org/10.1080/ 14622200701705357. Gini, G., Pozzoli, T., 2009. Association between bullying and psychosomatic problems: a meta-analysis. Pediatrics 123 (3), 1059–1065. Guerra, N.G., Bradshaw, C.P., 2008. Linking the prevention of problem behaviors and positive youth development: core competencies for positive youth development and risk prevention. New Dir. Child Adolesc. Dev. 2008 (122), 1–17. Hay, C., Evans, M.M., 2006. Violent victimization and involvement in delinquency: examining predictions from general strain theory. J. Crim. Just. 34 (3), 261–274. Hong, J.S., Espelage, D.L., 2012. A review of research on bullying and peer victimization in school: an ecological system analysis. Aggress. Violent Behav. 17 (4), 311–322. Hong, J.S., Davis, J.P., Sterzing, P.R., Yoon, J., Choi, S., Smith, D.C., 2014. A conceptual framework for understanding the association between school bullying victimization and substance misuse. Am. J. Orthopsychiatry 84 (6), 696. Jackson, C., 1998. Cognitive susceptibility to smoking and initiation of smoking during childhood: a longitudinal study. Prev. Med. 27 (1), 129–134. Jiang, D., Walsh, M., Augimeri, L.K., 2011. The linkage between childhood bullying behaviour and future offending. Crim. Behav. Ment. Health 21 (2), 128–135. Johnston, L.D., O'Malley, P.M., Bachman, J.G., Schulenberg, J.E., 2012. Monitoring the Future National Survey Results on Drug Use, 1975–2011: Volume II, College Students and Adults Ages 19–50. Institute for Social Research, The University of Michigan, Ann Arbor, MI (Retrieved from www.monitoringthefuture.org/pubs/monographs/ mtfvol2_2011.pdf). Kandel, D.B., 1978. Homophily, selection, and socialization in adolescent friendships. Am. J. Sociol. 427-436. Kelly, E.V., Newton, N.C., Stapinski, L.A., et al., 2015a. Suicidality, internalizing problems and externalizing problems among adolescent bullies, victims and bully–victims. Prev. Med. 73, 100–105. Kelly, E.V., Newton, N.C., Stapinski, L.A., et al., 2015b. Concurrent and prospective associations between bullying victimization and substance use among Australian adolescents. Drug Alcohol Depend. Liang, H., Flisher, A.J., Lombard, C.J., 2007. Bullying, violence, and risk behavior in South African school students. Child Abuse Negl. 31 (2), 161–171.

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Luukkonen, A.H., Riala, K., Hakko, H., Räsänen, P., 2010. Bullying behaviour and substance abuse among underage psychiatric inpatient adolescents. Eur. Psychiatry 25 (7), 382–389. Mayhew, K.P., Flay, B.R., Mott, J.A., 2000. Stages in the development of adolescent smoking. Drug Alcohol Depend. 59, 61–81. Moore, S.E., Norman, R.E., Sly, P.D., Whitehouse, A.J., Zubrick, S.R., Scott, J., 2014. Adolescent peer aggression and its association with mental health and substance use in an Australian cohort. J. Adolesc. 37 (1), 11–21. Nansel, T.R., Overpeck, M., Pilla, R.S., Ruan, W.J., Simons-Morton, B., Scheidt, P., 2001. Bullying behaviors among US youth: prevalence and association with psychosocial adjustment. JAMA 285 (16), 2094–2100. Newman, M.L., Holden, G.W., Delville, Y., 2005. Isolation and the stress of being bullied. J. Adolesc. 28 (3), 343–357. Niemelä, S., Brunstein-Klomek, A., Sillanmäki, L., et al., 2011. Childhood bullying behaviors at age eight and substance use at age 18 among males. A nationwide prospective study. Addict. Behav. 36 (3) (256–260). Olweus, D., 2013. School bullying: development and some important challenges. Annu. Rev. Clin. Psychol. 9, 751–780. Phillips, D.A., 2007. Punking and bullying strategies in middle school, high school, and beyond. J. Interpers. Violence 22 (2), 158–178. Pierce, J.P., Choi, W.S., Gilpin, E.A., Farkas, A.J., Merritt, R.K., 1996. Validation of susceptibility as a predictor of which adolescents take up smoking in the United States. Health Psychol. 15, 355–361. http://dx.doi.org/10.1037//0278-6133.15.5.355. Radliff, K.M., Wheaton, J.E., Robinson, K., Morris, J., 2012. Illuminating the relationship between bullying and substance use among middle and high school youth. Addict. Behav. 37 (4), 569–572. Rivers, I., Poteat, V.P., Noret, N., Ashurst, N., 2009. Observing bullying at school: the mental health implications of witness status. Sch. Psychol. Q. 24 (4), 211. Seo, D.C., Torabi, M.R., Weaver, A.E., 2008. Factors influencing openness to future smoking among nonsmoking adolescents. J. Sch. Health 78 (6), 328–336. Smith, P.K., Talamelli, L., Cowie, H., Naylor, P., Chauhan, P., 2004. Profiles of non-victims, escaped victims, continuing victims and new victims of school bullying. Br. J. Educ. Psychol. 74 (4), 565–581. Spriggs, A.L., Iannotti, R.J., Nansel, T.R., Haynie, D.L., 2007. Adolescent bullying involvement and perceived family, peer and school relations: commonalities and differences across race/ethnicity. J. Adolesc. Health 41 (3), 283–293. Srabstein, J.C., Leventhal, B.L., 2010. Prevention of bullying-related morbidity and mortality: a call for public health policies. Bull. World Health Organ. 88 (6), 403. Stern, R.A., Prochaska, J.O., Velicer, W.F., Elder, J.P., 1987. Stages of adolescent cigarette smoking acquisition: measurement and sample profiles. Addict. Behav. 12 (4), 319–329. Swearer, S.M., Espelage, D.L., Vaillancourt, T., Hymel, S., 2010. What can be done about school bullying? Linking research to educational practice. Educ. Res. 39 (1), 38–47. Tharp-Taylor, S., Haviland, A., D'Amico, E.J., 2009. Victimization from mental and physical bullying and substance use in early adolescence. Addict. Behav. 34 (6) (561–56). Ttofi, M.M., Farrington, D.P., Lösel, F., Loeber, R., 2011a. The predictive efficiency of school bullying versus later offending: a systematic/meta-analytic review of longitudinal studies. Crim. Behav. Ment. Health 21 (2), 80–89. Ttofi, M.M., Farrington, D.P., Lösel, F., Loeber, R., 2011b. Do the victims of school bullies tend to become depressed later in life? A systematic review and meta-analysis of longitudinal studies. J. Aggress. Confl. Peace Res. 3 (2), 63–73. Ttofi, M.M., Farrington, D.P., Lösel, F., 2012. School bullying as a predictor of violence later in life: a systematic review and meta-analysis of prospective longitudinal studies. Aggress. Violent Behav. 17 (5), 405–418. Valdebenito, S., Eisner, M., Farrington, D., Ttofi, M., Sutherland, A., 2015. School-based interventions for reducing disciplinary school exclusion: a systematic review and metaanalysis of cross-sectional studies. Aggress. Violent Behav. http://dx.doi.org/10.1016/ j.avb.2015.05.004. Veeranki, S.P., Mamudu, H.M., Anderson, J.L., Zheng, S., 2014. Worldwide never-smoking youth susceptibility to smoking. J. Adolesc. Health 54 (2), 144–150. Vieno, A., Gini, G., Santinello, M., 2011. Different forms of bullying and their association to smoking and drinking behavior in Italian adolescents. J. Sch. Health 81 (7), 393–399. Weiss, J.W., Mouttapa, M., Cen, S., Johnson, C.A., Unger, J., 2011. Longitudinal effects of hostility, depression, and bullying on adolescent smoking initiation. J. Adolesc. Health 48 (6), 591–596. Wilkinson, A.V., Waters, A.J., Vasudevan, V., Bondy, M.L., Prokhorov, A.V., Spitz, M.R., 2008. Correlates of susceptibility to smoking among Mexican origin youth residing in Houston, Texas: a cross-sectional analysis. BMC Public Health 8 (1), 337. World Health Organization, 2002. World report on violence and health. Retrieved June 2015, from http://www.who.int/violence_injury_prevention/violence/ world_ report/en/full_en.pdf.