Smoking family, secondhand smoke exposure at home, and nicotine addiction among adolescent smokers

The association between urinary cotinine level and metabolic syndrome profiles among adolescents: findings from the Ewha Birth and growth study

BACKGROUND

Secondhand smoke (SHS) exposure among adolescents who are still developing can negatively affect their physical and psychological health, including metabolic syndrome (MetS), which is a risk factor for cardiovascular disease. However, the relationship between exposure to SHS and MetS in adolescence has not been evaluated.

METHODS

A total of 240 subjects aged 13-15 years who were followed up in the Ewha Birth and Growth Study were included in this study. Using the urinary cotinine level, the participants' exposure to SHS was divided into tertiles, and the continuous MetS score (cMetS) and its components were compared among the three groups using a generalized linear model and trend analysis. Univariate and multivariate linear regression analyses were performed. We adjusted for several confounding variables including sex, father's education level, father's current alcohol consumption status, moderate physical activity, and overweight status.

RESULTS

The association between cMetS and the urinary cotinine level was not significant. However, the higher the urinary cotinine level, the lower the high-density lipoprotein cholesterol (HDL-C) level. In particular, the significance of the HDL-C level was maintained after adjusting for covariates.

CONCLUSIONS

This study supports an association between SHS exposure and the components of MetS in adolescents aged 13-15 years, and it suggests the need to address SHS exposure in adolescents to reduce the cardiovascular risk in later life.

Prevalence, frequency, intensity, and location of cigarette use among adolescents in China from 2013-14 to 2019: Findings from two repeated cross-sectional studies

BACKGROUND

The burden of disease caused by tobacco use is a grave public health concern in China. Preventing smoking initiation among adolescents will lower the prevalence of adult tobacco use later. Surveillance of tobacco use among adolescents helps set priorities in developing tobacco control policies. We aim to ascertain the prevalence and differences of cigarette use across sex, grade, and region among middle and high school students in 2019 and associated changes from 2013-14 to 2019 among middle school students.

METHODS

Using a multistage stratified cluster-randomized sampling design with national and provincial representativeness, we conducted two school-based cross-sectional surveys in 2013-14 and in 2019. A total of 155 117 middle school students in grades 7-9 in 2013-14 and 288 192 middle and high school students in grades 7-12 in 2019 were interviewed. Self-reported experimental and current (past 30-day) cigarette use among middle school and high school students; frequent use (≥20 days in the past 30 days) and intensity (>20 cigarettes per day) of smoking among current cigarette users; and location of smoking among current cigarette users were investigated. All estimates were weighted based on the complex sampling design.

FINDINGS

The 2013-14 survey (overall response rate: 98.1%) included 155 117 middle school students (47.1% girl). The 2019 survey (overall response rate: 98.7%) included 147 270 middle school students (46.5% girl), 106 432 academic high school students (50.8% girl) and 34 490 vocational high school students (43.8% girl). In 2019, the prevalence rate of experimental and current cigarette use was 12.9% and 3.9% for middle school students, 21.6% and 5.6% for academic high school students, and 30.3% and 14.7% for vocational high school students, respectively, with large sex and regional differences. The prevalences of smoking on 20 or more days and daily cigarette use in the past 30 days were higher in vocational high school (5.9%, 4.1%) than in academic high school (1.8%, 1.2%) and middle school (0.7%, 0.5%), and higher among boys than girls. The proportions of current cigarette users smoking more than 20 cigarettes per day in the past 30 days for girls were higher than for boys in academic high school. Students usually smoke at school and at home. Boys were more likely to use cigarettes in an internet cafe, while girls often smoked at social venues. From 2013-14 to 2019, the prevalences of experimental and current cigarette use declined by 5.0% and 2.0% (percentage points), respectively, among middle school students but increased by 1.4% and 0.5% (percentage points) among rural girls. Among current cigarette users in middle school students, the proportions of heavy cigarette use (>20 cigarettes per day) have increased by 1.8 percentage points, mainly among boys, by 2.2% (percentage points).

INTERPRETATION

From 2013-14 to 2019, the prevalences of experimental and current cigarette use among middle school students decreased overall but increased among rural girls, while the intensity of cigarette use rose among boys. Cigarette use among Chinese adolescents differs across sex and regions, with higher rates among boys, in rural areas, and in the Western region (low socioeconomic status). Smoking is much more prevalent in vocational high schools than the other settings. Effective targeted tobacco control interventions among adolescents are urgently needed in China.

FUNDING

Dr. Zhuo Chen is supported by National Natural Science Foundation (Grant#: 72174098) through the University of Nottingham Ningbo China.

Prenatal Morphine Exposure Differentially Alters Addictive and Emotional Behavior in Adolescent and Adult Rats in a Sex-Specific Manner

The effects of prenatal opioid exposure in adult animals has been widely studied, but little is known about the effects of prenatal opioid on adolescents. Most of the risk behaviors associated with drug abuse are initiated during adolescence. The developmental state of the adolescent brain makes it vulnerable to initiate drug use and susceptible to drug-induced brain changes. In this study, pregnant rats were subcutaneously injected with an increasing dose of morphine (5 mg/kg, 7 mg/kg, 10 mg/kg) for 9 days since the gestation day 11. The effects of prenatal morphine (PNM) on learning and memory, anxiety- and depressive- like behavior, morphine induced conditioned place preference (CPP) as well as locomotor sensitization were tested in both adolescent and adult rats. The results showed that: (1) PNM decreased anxiety-like behavior in both adolescent and adult female rats, but not males; (2) PNM decreased depressive-like behavior in adolescent but increased depressive -like behavior in adult females; (3) PNM increased low dose morphine induced locomotor sensitization in females; (4) PNM decreased tyrosine hydroxylase (TH) expression in the prefrontal cortex but decreased dopamine D1 receptor expression in the nucleus-accumbens (NAc) in female rats. These results suggested that PNM altered the emotional and addictive behavior mainly in female rats, with female rats being less anxiety and depressive during adolescence, but more depressive in adult, and more sensitive to low dose morphine induced locomotor activity sensitization, which might be mediated in part by the differential expression of the TH, dopamine D1 receptors in the female brain.

Is exposure to indoor secondhand smoke associated with poor mental health? Results from non-conflict and post-conflict setting

The purpose of this study was to examine the association between exposure to indoor SHS and self-reported HRQoL among healthy non-smoking students at the University of Belgrade, Serbia and Kosovska Mitrovica located in the post-conflict Kosovo province. Students who presented at Student Public Health Center in Belgrade in 2009 and Kosovska Mitrovica in 2015 for mandatory health checks were invited to participate. Data were collected using socio-demographic and behavioral questionnaire, health-related quality of life questionnaire Short Form-36 (SF-36) and Beck Depression Inventory (BDI). A total of 82.3% students in Belgrade sample and 76.0% in Kosovska Mitrovica sample reported daily exposure to indoor SHS. After adjustment for socio-demographic characteristics and behavior, daily exposure to indoor SHS for more than 6 hours was associated with poorer Vitality (β = -5.55, 95% confidence interval [CI] -9.49, -1.61) and Mental Health (β = 5.00, 95% CI-8.94, -1.07) only among students at the University of Belgrade. This study showed that the association between longer daily indoor SHS exposure and poor mental health HRQoL was not consistent in non-conflict and post-conflict setting. This association was not found in a post-conflict setting. Strict no smoking policies are needed in student housing, university campuses and all public spaces.

Adolescent Smoking in Hong Kong: Prevalence, Psychosocial Correlates, and Prevention

Preventing adolescent smoking is important as smoking is typically initiated by young people. This article reviews the prevalence, psychosocial correlates, and prevention of smoking in Hong Kong adolescents. The past 30-day smoking prevalence in adolescents decreased from 9.6% in 2003 to 2.5% in 2017. Tobacco advertisements, parental and best friends smoking, nonintact families, poor family relationships, lower socioeconomic status, being a new immigrant, poor knowledge of smoking-related harm, positive attitudes toward smoking, overestimation of peer smoking, and depressive symptoms were positively associated with smoking outcomes, whereas positive youth development, authoritative mother and permissive father, family functioning, school competence, and stronger tobacco industry denormalization beliefs were protective against smoking. Along with tobacco tax increase, ban on tobacco advertisements, smoke-free law and pictorial warnings, educational efforts through theater performances, social norms campaigns, and positive adolescent training programs have been conducted to prevent adolescent smoking. To achieve the ultimate goal of tobacco endgame, further tax increase, plain packaging, banning point-of-sale display of tobacco products, smoke-free area extension, and raising minimum age of purchase should be implemented. The government proposed law to ban e-cigarettes, and heated tobacco products should be passed soon to protect children and adolescents from using these products.

Associations Between Secondhand Tobacco Smoke Exposure and Nicotine Dependence and Smoking Cessation Attempts Among Adult Tobacco Users With a Psychiatric Disorder

INTRODUCTION

Secondhand smoke exposure (SHSe) is predictive of greater nicotine dependence (ND) and poor smoking cessation (SC) outcomes. SHSe and its impact on ND and SC attempts in people with psychiatric disorders (PD) remain poorly understood. Hence, the objectives of this study were to (1) quantify SHSe, (2) examine the association of SHSe with ND, and (3) assess the association between SHSe and SC among tobacco users with PD.

METHOD

A cross-sectional survey of 118 tobacco users in an inpatient psychiatric facility was conducted. Data on demographics, tobacco use and SHSe history, motivation to quit smoking, ND, and SC attempts were obtained. Participants' environmental and psychosocial sources of and perceived SHSe were described. Multivariate linear regression analyses were used to examine the associations between SHSe and ND, while logistic regression analyses were used to assess the associations between SHSe and SC.

RESULTS

The primary sources of environmental SHSe were from the car (63.6%) and home (51.7%); primary sources of psychosocial SHSe were close friends (67.8%) and parents/grandparents (65.3%); and mean perceived SHSe was 6.2 ( SD = 3.5). Although perceived SHSe was significantly associated with ND (β = .39, p < .0001) in multivariate analyses, no SHSe variable was associated with SC. However, scores on items measuring motivation to quit smoking were associated with SC attempts.

DISCUSSION

Patients with PD reported high levels of SHSe, which was associated with higher ND. Routine screening for SHSe should be implemented as part of health assessments in this population to address ND treatment options. Moreover, targeted interventions and policies should be considered toward reducing SHSe in this vulnerable population.

Environmental Tobacco Exposure and Urinary Cotinine Levels in Smoking and Nonsmoking Adolescents

Objective

We aimed to evaluate the association between environmental tobacco smoke (ETS) exposure and urinary cotinine levels in current adolescent smokers and nonsmokers. The secondary objective was to explore the association between ETS exposure and nicotine dependence in adolescent smokers.

Methods

Using the results from a validation study for the 2012 Global Youth Tobacco Survey in Mexico, we quantified urinary cotinine levels in adolescent smokers and nonsmokers. We fitted a multivariate regression model to assess the association between household exposure to ETS and cotinine levels in adolescent smokers and nonsmokers. In addition, using the questionnaire's answers for morning cravings, we fitted a multivariate Poisson regression model to explore the association between household ETS exposure and nicotine dependence in adolescent smokers.

Results

For each day of household ETS exposure, cotinine levels increase by 5% in adolescent smokers compared to a 2% increase in nonsmokers, adjusting for the number of cigarettes smoked per week, age and sex (exp(β) 1.05; 95% confidence interval [CI] [1.00, 1.10]; p = .041). Morning cravings increase 11% for each day of household ETS exposure adjusting for the number of cigarettes smoked per week, age and sex (prevalence ratio [PR] 1.11; 95% CI [0.99, 1.25]; p = .064).

Conclusions

There is an association between ETS exposure and cotinine levels, and ETS may contribute to nicotine dependence in adolescent smokers. If confirmed, avoiding ETS exposure could prove helpful for addiction control and quitting in adolescents.

Implications

Evidence suggests that ETS increases cotinine levels in nonsmokers and adult smokers. However, no study has explored the association between ETS exposure and cotinine levels and addiction in adolescent smokers. This paper provides evidence of an association between ETS exposure and cotinine levels in adolescent smokers: each day of environmental tobacco smoke exposure at home increased cotinine levels by 5% among smokers. In addition, morning cravings in adolescent smokers increased 11% for every day of ETS exposure. ETS exposure is a significant source of nicotine for adolescent smokers and could play an important role in addiction.

Cardiovascular Consequences of Childhood Secondhand Tobacco Smoke Exposure: Prevailing Evidence, Burden, and Racial and Socioeconomic Disparities: A Scientific Statement From the American Heart Association

BACKGROUND

Although public health programs have led to a substantial decrease in the prevalence of tobacco smoking, the adverse health effects of tobacco smoke exposure are by no means a thing of the past. In the United States, 4 of 10 school-aged children and 1 of 3 adolescents are involuntarily exposed to secondhand tobacco smoke (SHS), with children of minority ethnic backgrounds and those living in low-socioeconomic-status households being disproportionately affected (68% and 43%, respectively). Children are particularly vulnerable, with little control over home and social environment, and lack the understanding, agency, and ability to avoid SHS exposure on their own volition; they also have physiological or behavioral characteristics that render them especially susceptible to effects of SHS. Side-stream smoke (the smoke emanating from the burning end of the cigarette), a major component of SHS, contains a higher concentration of some toxins than mainstream smoke (inhaled by the smoker directly), making SHS potentially as dangerous as or even more dangerous than direct smoking. Compelling animal and human evidence shows that SHS exposure during childhood is detrimental to arterial function and structure, resulting in premature atherosclerosis and its cardiovascular consequences. Childhood SHS exposure is also related to impaired cardiac autonomic function and changes in heart rate variability. In addition, childhood SHS exposure is associated with clustering of cardiometabolic risk factors such as obesity, dyslipidemia, and insulin resistance. Individualized interventions to reduce childhood exposure to SHS are shown to be at least modestly effective, as are broader-based policy initiatives such as community smoking bans and increased taxation.

PURPOSE

The purpose of this statement is to summarize the available evidence on the cardiovascular health consequences of childhood SHS exposure; this will support ongoing efforts to further reduce and eliminate SHS exposure in this vulnerable population. This statement reviews relevant data from epidemiological studies, laboratory-based experiments, and controlled behavioral trials concerning SHS and cardiovascular disease risk in children. Information on the effects of SHS exposure on the cardiovascular system in animal and pediatric studies, including vascular disruption and platelet activation, oxidation and inflammation, endothelial dysfunction, increased vascular stiffness, changes in vascular structure, and autonomic dysfunction, is examined.

CONCLUSIONS

The epidemiological, observational, and experimental evidence accumulated to date demonstrates the detrimental cardiovascular consequences of SHS exposure in children.

IMPLICATIONS

Increased awareness of the adverse, lifetime cardiovascular consequences of childhood SHS may facilitate the development of innovative individual, family-centered, and community health interventions to reduce and ideally eliminate SHS exposure in the vulnerable pediatric population. This evidence calls for a robust public health policy that embraces zero tolerance of childhood SHS exposure.

Smoking habits and nicotine dependence of North Korean male defectors

BACKGROUND/AIMS

The smoking rates and patterns in the North Korean population are not well known. More than 20,000 North Korean defectors have settled in South Korea; thus, we can estimate the current North Korean smoking situation using this group.

METHODS

All North Korean defectors spend their first 3 months in a South Korean facility learning to adapt to their new home. We retrospectively analyzed the results from a questionnaire conducted among North Korean male defectors in this facility from August 2012 to February 2014.

RESULTS

Of 272 men, 84.2% were current smokers, 12.5% were ex-smokers, and 3.3% were non-smokers. The mean age of this group was 35.9 ± 11.3 years, and smoking initiation occurred at a mean age of 18.2 ± 4.7 years. Among the subjects, 78.1% had a family member who smoked. Of the 221 current smokers, 67.4% responded that they intended to quit smoking. Fagerström test and Kano test for social nicotine dependence (KTSND) results for current smokers were 3.35 ± 2.26 and 13.76 ± 4.87, respectively. Question 9 on the KTSND (doctors exaggerate the ill effects of smoking) earned a significantly higher score relative to the other questions and a significantly higher score in current smokers compared with non-smokers.

CONCLUSIONS

The smoking rate in North Korean male defectors was higher than that indicated previously. However, interest in smoking cessation was high and nicotine dependence was less severe than expected. Further investigation is needed to identify an efficient method for North Korean smokers to stop smoking.

Secondhand tobacco smoke exposure and susceptibility to smoking, perceived addiction, and psychobehavioral symptoms among college students

OBJECTIVE

To examine the association of secondhand smoke (SHS) exposure with susceptibility to smoking, perceived addiction, and psychobehavioral effects of exposure among never- and ever-smoking college students.

PARTICIPANTS

Participants were 665 college students at a large, southeastern university in the United States.

METHODS

This study is a secondary analysis of online cross-sectional survey data from randomly selected students in April 2013.

RESULTS

Thirty-eight percent of the sample had moderate to high SHS exposure. Among never-smokers, SHS exposure was associated with increased susceptibility to initiating smoking. Among ever-smokers, SHS exposure was not associated with their perceived addiction to tobacco. In the total sample, SHS exposure was associated with greater psychobehavioral symptoms of exposure.

CONCLUSIONS

SHS exposure may the increase risk of smoking, especially among never-smoking college students. This study strengthens the need for prevention strategies that limit SHS exposure in college environments.

Electronic cigarette use and its association with smoking in Hong Kong Chinese adolescents

BACKGROUND

Electronic cigarettes (e-cigarettes) are increasingly used in adolescents with unknown impacts on conventional cigarette smoking. We examined the associations of e-cigarette use with smoking intention, nicotine addiction and smoking cessation in Chinese adolescents.

METHODS

A total of 45,128 students (age 14.6 ± 1.9; boys 51.4%) from 75 randomly selected schools in Hong Kong reported e-cigarette use (in the past 30 days), conventional cigarette use and socio-demographic characteristics in an anonymous questionnaire survey. Adjusted odds ratios (AORs) of intention to smoke, morning smoking urge, intention to quit and quit attempts; and beta-coefficient (β) of cigarette consumption per day were calculated in relation to e-cigarette use.

RESULTS

E-cigarette use was associated with intention to smoke with an AOR (95% CI) of 1.74 (1.30-2.31) in all students, 2.18 (1.12-4.23) in never and 2.79 (2.05-3.79) in ever smokers (non-significant interaction by smoking status). The associations were also significant in experimental and former smokers but not in current smokers. In current smokers, e-cigarette use was significantly associated with heavier smoking (β 2.54, 95% CI 1.28-3.81) and morning smoking urge (AOR 2.54, 95% CI 1.50-3.11), and non-significantly associated with lower quit intention (0.76, 0.52-1.09) and attempts (0.80, 0.56-1.23).

CONCLUSIONS

E-cigarette use was associated with smoking intention in never, experimental and former smokers in Hong Kong Chinese adolescents. In current smokers, e-cigarette use was associated with nicotine addiction but not quit intention and attempts. Prospective studies with detailed measurements on e-cigarette use are warranted for further studies.

A systematic review of secondhand tobacco smoke exposure and smoking behaviors: Smoking status, susceptibility, initiation, dependence, and cessation

OBJECTIVES

To examine the association between secondhand tobacco smoke exposure (SHSe) and smoking behaviors (smoking status, susceptibility, initiation, dependence, and cessation).

METHODS

Terms and keywords relevant to smoking behaviors and secondhand tobacco smoke exposure were used in a search of the PubMed database. Searches were limited to English language peer-reviewed studies up till December 2013. Included papers: a) had clearly defined measures of SHSe and b) had clearly defined measures of outcome variables of interest. A total of 119 studies were initially retrieved and reviewed. After further review of references from the retrieved studies, 35 studies were finally selected that met all eligibility criteria.

RESULTS

The reviewed studies consisted of thirty-five (89.7%) studies with differing measures of SHSe (including questionnaire and biological measures) and varying definitions of main outcome variables of interest between studies. The majority of the studies (77%) were cross-sectional in nature. The majority of studies found that SHSe was associated with greater likelihood of being a smoker, increased susceptibility and initiation of smoking, greater nicotine dependence among nonsmokers, and poorer smoking cessation.

CONCLUSIONS

The review found positive associations between SHSe and smoking status, susceptibility, initiation and nicotine dependence and a negative association with smoking cessation. In light of design limitations, future prospective and clinical studies are needed to better understand the mechanisms whereby SHSe influences smoking behaviors.

Secondhand smoke exposure and serum cotinine levels among current smokers in the USA

BACKGROUND

Secondhand smoke (SHS) likely provides additional exposure to nicotine and toxins for smokers, but has been understudied. Our objective was to determine whether SHS exposure among smokers yields detectable differences in cotinine levels compared with unexposed smokers at the population level.

METHODS

Using the US National Health and Nutrition Examination Survey (NHANES) for the years 1999-2012, we compared serum cotinine levels of 4547 current adult cigarette smokers stratified by self-reported SHS exposure sources (home and/or work) and smoking intensity. A weighted multivariable linear regression model determined the association between SHS exposure and cotinine levels among smokers.

RESULTS

Smokers with SHS exposure at home (43.8%) had higher cotinine levels (β=0.483, p≤0.001) compared with those with no SHS exposure at home after controlling for the number of cigarettes smoked per day and number of days smoked in the previous 5 days, survey year, age, gender and education. Smokers with SHS exposure at work (20.0%) did not have significantly higher cotinine levels after adjustment. The adjusted geometric mean cotinine levels of light smokers (1-9 cigarettes per day) with no SHS exposure, exposure at work only, home only, and both home and work were 52.0, 62.7, 67.2, 74.4 ng/mL, respectively, compared with 219.4, 220.9, 255.2, 250.5 ng/mL among moderate/heavy smokers (≥10 cigarettes per day).

CONCLUSIONS

Smokers living in residences where others smoke inside the home had significantly higher cotinine levels than smokers reporting no SHS exposure, regardless of individual smoking intensity. Future research should target the role that SHS exposure may have in nicotine dependence, cessation outcomes and other health impacts among smokers.

Correlates of current smoking among Malaysian secondary school children

Cigarette smoking in adolescent is a significant public health problem, leading to the risk of addiction, morbidity, and mortality in the long term. This study determined the prevalence and correlates of current smoking among adolescent school children. A nationwide school-based survey among 25 507 students between Forms 1 to 5 (aged 12-17) was conducted using a 2-stage cluster sampling design. The prevalence of current smoking was 11.5%. Multivariable logistic regression analysis revealed that current smoking was significantly associated with males (adjusted odds ratio [aOR] = 3.25; 95% confidence interval [CI] = 1.87, 4.98), current drinking (aOR = 2.34; 95% CI = 1.46, 3.74), drug used (aOR = 2.97; 95% CI = 1.24, 7.11), and being bullied (aOR = 1.41; 95% CI = 1.00, 1.98) at least once in the past 12 months. Smoking is associated with several behaviors that pose risks to adolescents, such as social issues and smoking-related health problems. Thus, early and integrated prevention programs that address multiple risk behaviors simultaneously are required.

Predictors of intention to smoke among junior high school students in Shanghai, China: an empirical test of the information-motivation-behavioral skills (IMB) model

Background

Adolescent smoking is a worldwide problem that is particularly severe in low- and middle-income countries. Many endogenous and environmental factors affect the intention to smoke, so a comprehensive model is needed to understand the significance and relationship of predictors. The study aimed to test the associations among information-motivation-behavioral skills (IMB) model constructs as predictors of intention to smoke in junior high school students in Shanghai, China.

Methods

We conducted a cross-sectional study of 16,500 junior high school students in Shanghai, China. Data on tobacco-related information, motivation, behavioral skills, and behaviors were collected from students. Structural equation model (SEM) was used to assess the IMB model.

Results

The mean age of participants was 13.8 years old (standard deviation = 1.02; range 11–17). The experimental smoking rate among junior high school students was 6.6% and 8.7% of the participants expected that they would be smokers in 5 years. The IMB model provided acceptable fit to the data (comparative fit index = 0.984, root mean square error of approximation = 0.04). Intention to smoke was predicted by behavioral skills (β= 0.670, P < 0.001) and motivation (β= 0.095, P<0.001) among junior high school students.

Conclusion

The IMB model provides a good understanding of the predictors of intention to smoke and it suggests future interventions among junior high school students should focus on improving motivation and behavioral skills.

Secondhand smoke exposure and health services use among adolescent current smokers

Background

To investigate the associations of secondhand smoke (SHS) exposure with medical consultation and hospitalisation among adolescents in Hong Kong.

Methods

A total of 35827 secondary 1 (US grade 7) to secondary 5 students from 85 randomly selected schools completed an anonymous questionnaire on smoking, SHS at home, SHS outside home, medical consultation in the past 14 days, hospitalisation in the past 12 months, and socio-demographic characteristics. Current smoking was defined as any smoking in the past 30 days. SHS exposure was classified as none (reference), 1–4 and 5–7 days/week. Logistic regression yielded adjusted odds ratios (AORs) for medical consultation and hospitalisation in relation to SHS exposure at home and outside home in current smokers. Analyses were also done among never-smokers for comparison.

Results

Among all students, 15.9% had medical consultation and 5.2% had been hospitalised. Any SHS exposure at home was associated with AORs (95% CI) for medical consultation and hospitalisation of 1.69 (1.14–2.51) and 2.85 (1.47–5.52) in current smokers, and 1.03 (0.91–1.15) and 1.25 (1.02–1.54) in never-smokers, respectively, (P<0.01 for interaction between smoking status and SHS exposure at home). SHS exposure outside home was generally not associated with medical consultation and hospitalisation in smokers and never-smokers.

Conclusions

SHS exposure at home was associated with health services use among adolescent current smokers. Adolescent smokers should be aware of the harm of SHS in addition to that from their own smoking. The evidence helps health care professionals to advise adolescent smokers to avoid SHS exposure and stop smoking.