Childhood predictors of smoking in adolescence: a follow-up study of Montreal schoolchildren

Secondhand Smoke Exposure and Smoking Prevalence Among Adolescents

Importance

Secondhand smoke is a substantial risk factor for youth health globally, including in Japan, where tobacco control policies should be reassessed.

Objective

To assess trends in the prevalence of secondhand smoke exposure among Japanese adolescents from 2008 to 2017 and to examine the association between its frequency and smoking during the study period.

Design, Setting, and Participants

This study comprised a nationally representative, self-administered, school-based, cross-sectional survey focusing on tobacco and alcohol use and related factors among students in grades 7 to 12 (ages 12-18 years) in Japan. This random sampling survey used single-stage cluster sampling. Using the national school directory, junior and senior high schools throughout Japan were randomly extracted from each regional block. All students enrolled in the sampled schools were included as participants, and school-based surveys were completed in 2008, 2012, and 2017. Data analysis was performed from January 1 to March 15, 2023.

Main Outcomes and Measures

Prevalence of secondhand smoke exposure among adolescents in Japan from 2008 to 2017 and changes in the association between secondhand smoke exposure frequency and prevalence of smoking were examined using multiple logistic regression analysis.

Results

Data were analyzed for 95 680 adolescents in 2008 (50.7% boys), 100 050 in 2012 (51.6% boys), and 64 152 in 2017 (53.9% boys). At baseline, 42.0%, 38.5%, and 34.6% of the participants were junior high school students in 2008, 2012, and 2017, respectively. Based on the 2008 surveys, 51.0% of adolescents in grades 7 to 12 were exposed to secondhand smoke in any place (≥1 day during the past 7 days), 37.2% were exposed at home, and 36.5% were exposed in public places. In 2017, 36.3% of participants were exposed to secondhand smoke in any place, 23.8% were exposed at home, and 27.0% were exposed in public places. An association between secondhand smoke exposure frequency and prevalence of smoking was observed consistently regardless of survey year, location, or pattern of exposure (adjusted odds ratios ranged from 2.29 [95% CI, 1.81-2.91] for 1-2 days at home to 11.15 [95% CI, 8.50-14.62] for 7 days in public places). Stratified analysis by higher education intention indicated that the prevalence of smoking and secondhand smoke exposure decreased but remained higher among adolescents who did not intend to pursue higher education. The association between secondhand smoke and smoking did not differ substantially between groups.

Conclusions and Relevance

In this cross-sectional study, the prevalence of secondhand smoke exposure among adolescents in Japan decreased but remained at high levels overall. There may not be a hazard-free threshold for smoking. Enhancing comprehensive tobacco control strategies is Japan's first step toward achieving smoke-free environments to protect youths. Implementation and verification of the effectiveness of smoke-free legislation should be considered.

Profiles of Nicotine and Cannabis Exposure among Young Adults with Asthma

There is a paucity of data on nicotine and cannabis use among young adults (YAs) with asthma. This study aimed to do the following among YAs with asthma: (1) describe YAs' active and passive exposure to nicotine and cannabis; (2) identify latent classes of active use of nicotine and cannabis; and (3) explore predictors of class membership (i.e., demographics, parental and friend use of nicotine and cannabis, and hours of environmental exposure to tobacco smoke, e-cigarette vapor, and marijuana smoke). YAs with asthma (N = 178) self-reported on nicotine and cannabis exposure and the included covariates. Latent class analysis was used to identify latent classes of lifetime nicotine and cannabis use. High rates of nicotine and cannabis use among YAs with asthma were found: 37% reporting a lifetime history of using both nicotine and cannabis. Regarding past year use, 25% had smoked cigarettes, 40% had used e-cigarettes, and 35% had used cannabis. Five classes of lifetime use were identified. The largest class was a non-user class (53%); the other four classes indicate concerning patterns of nicotine and cannabis use. The most consistent predictor of being in a class characterized by more nicotine and cannabis exposure (versus being in the non-user class) was past week exposure to cannabis smoke. This is the first study to identify classes of lifetime nicotine and cannabis use, and examine predictors of class membership, among YAs with asthma. There is a critical need to address environmental and active tobacco and marijuana exposure among YAs with asthma.

Responsibility, normalisation and negotiations of harm: E-cigarette users' opinions and experiences of vaping around children

BACKGROUND

Concern about youth uptake of vaping is widespread. Regulation and education campaigns aim to protect children from initiating use, yet it is likely that children will be primarily influenced by the behaviour of people in their immediate environment. This is the first known study exploring e-cigarette users' views and reported experiences of vaping around children.

METHODS

Following informed consent, semi-structured qualitative interviews were conducted with 40 adults who had attempted to give up smoking by vaping. Participants were recruited from England as part of a wider study into e-cigarette use trajectories and smoking relapse (ECtra study). Data were extracted from 28 interviews where participants had spontaneously discussed vaping around children. Extracted data were analysed thematically and situated in previous analysis of vaping identity which distinguished between recreational and medicinal vapers.

RESULTS

Vaping behaviour around children was in part a habituated replication of smoking norms but also guided by broad vaping identity; recreational users were more permissive and medicinal users more secretive. Vaping in the home appeared to be determined by caregivers' need to reconcile vaping behaviour so that it was congruent with parental identity as a responsible caregiver. Participant perspectives reflected existing moral discourses applied to e-cigarettes around the use of "harm reduction for smokers" and "potential for youth harm".

CONCLUSION

Vaping is likely to be role modelled within the community and home despite attempts by e-cigarette users to conceal the behaviour. The ambivalent contextualisation of e-cigarettes means that e-cigarette users may lack a clear narrative to draw on when discussing vaping with children. Public health guidance for vaping around children could be helpful, but to be most effective, should take into consideration users' vaping identity.

Pattern of cigarette smoking: intensity, cessation, and age of beginning: evidence from a cohort study in West of Iran

BACKGROUND

Smoking is a social epidemic and one of the main risk factors for premature deaths and disabilities worldwide. In the present study, we investigated the Pattern of Cigarette Smoking: intensity, cessation, and age of the beginning.

METHODS

Data collected from the recruitment phase of Ravansar (a Kurd region in western Iran) Non-Communicable Disease (RaNCD) cohort study was analyzed by using Chi-square test, univariate and multivariate logistic regressions, Poisson regression, and linear regression.

RESULTS

Totally 10,035 individuals (47.42% males) participated in the study. Mean age was lower for males (47.45 yr) than for females (48.36 yr). Prevalence of smoking was 20% (36.4% of males and 5.23% of females). Compared to female participants, males showed a 7-fold higher prevalence of smoking and started smoking about 4 years earlier. Being married, having a lower BMI, living in rural areas, and being exposed to secondhand smoke (SHS) were predictors of higher smoking prevalence rates. Furthermore, current exposure to SHS, higher smoking intensity, later smoking initiation, male gender, younger age, lower education, and lower BMI were related to lower likelihood of stopping smoking. Heavy smokers began to smoke about 4 years earlier than casual smokers did. Finally, being divorced/ widow/ widower/ single and childhood exposure to SHS were found to increase the likelihood of becoming a smoker.

CONCLUSIONS

Based on present research results, health programs specific to smoking cessation should take socio-demographic factors, smoking history, and current smoking behavior into account.

Addressing Ethnic Disparities in Adolescent Smoking: Is Reducing Exposure to Smoking in the Home a Key?

INTRODUCTION

Smoking among New Zealand (NZ) adolescents has declined since 2000, but ethnic disparities remain pronounced. To inform prevention efforts, we investigated exposure to and relative importance of known predictors of adolescent smoking and how these have changed over time, for Māori (NZ's indigenous population) and adolescents overall.

METHODS

We used repeat cross-sectional data, 2003-2015, from a national survey of 14- to 15-year olds (N = 20 443-31 696 per year). For the overall sample and for Māori and non-Māori, we calculated adjusted odds ratios (aORs) to assess the association between regular smoking and risk factors each year: one or more parents smoke, best friend smokes, older sibling(s) smoke, and past week exposure to smoking in the home. We calculated population attributable risk (PAR) for risk factors in 2003 and 2015.

RESULTS

Between 2003 and 2015, aORs for exposure to smoking in the home increased from 1.7 (95% CI 1.6% to 1.8%) to 2.6 (2.1% to 3.1%) overall and from 1.8 (1.6% to 2.1%) to 3.4 (2.5% to 4.5%) for Māori; aORs for "best friend smokes" also increased, while aORs for sibling smoking and parental smoking did not change meaningfully. PAR for exposure to smoking in the home increased from 17% to 31% overall and from 28% to 57% for Māori, while PARs for other risk factors decreased.

CONCLUSIONS

Exposure to smoking in the home has become more strongly associated with adolescent smoking over time and is an increasingly important risk factor at the population level (independent of parental smoking), particularly for Māori.

IMPLICATIONS

Our findings have implications for reducing smoking uptake and ethnic disparities in NZ, and potentially elsewhere, given the similarity in risk factors and trends for adolescent smoking internationally. Our findings suggest that reducing second-hand smoke exposure in homes will likely reduce uptake of smoking. Because Māori children are both more exposed and appear to be more strongly influenced by exposure to smoking in the home, interventions to reduce indoor smoking could have differentially positive effects for Māori. Greater research and policy attention to reducing smoking in homes is warranted.

Exposure to second-hand smoke among secondary school-going adolescents: Findings from the Malaysian Adolescent Health Risk Behaviour (MyAHRB) study

Background:

Exposure to second-hand smoke (SHS) is one of the main causes of morbidity and it has been proven to be associated with an increased likelihood of smoking initiation among adolescents. Nonetheless, evidence on SHS exposure among Malaysian adolescents is scarce. Therefore, this article aims to demonstrate the magnitude and factors associated with SHS exposure among school-going adolescents in selected secondary schools in Peninsular Malaysia.

Methods:

Data were derived from the Malaysian Adolescent Health Risk Behaviour (MyAHRB) study conducted in 2013. A total of 2599 adolescent were recruited into the study using a two-stage proportionate-to-size sampling method. Data were obtained from self-administered questionnaires. Descriptive analysis and multivariable logistic regression were performed to determine the risk factors/predictors associated with SHS.

Results:

More than half of the respondents had been exposed to SHS during the last one week (56.4%), and SHS exposure was significantly higher among respondents who smoked (94.0% vs. 49.9%, p <0.001). Multivariable analysis revealed that the likelihood of exposure to SHS was higher among those who smoked (adjusted odds ratio (aOR) 12.90, 95% confidence interval (CI): 8.01–20.4), had at least one parent/guardian who smoked (aOR 5.49, 95% CI: 4.41–6.94) and adolescents of Malay descent (aOR 2.10, 95% CI: 1.68–2.63).

Conclusion:

Our findings suggested that the effectiveness of anti-smoking measures implemented in recent years to protect adolescents from the health risks of passive smoking were less evident. Therefore, educational and awareness programmes that emphasize the negative health impacts of SHS exposure on Malaysian adolescents, particularly when among smoking adults, should be intensified to help in preventing adoption of smoking behaviours among adolescents.

Why has adolescent smoking declined dramatically? Trend analysis using repeat cross-sectional data from New Zealand 2002-2015

OBJECTIVES

Adolescent smoking has declined in New Zealand and in many other countries since the late 1990s, yet the reasons for the decline are not well understood. We investigated the extent to which established risk factors for adolescent smoking (parental, sibling and peer smoking, and exposure to smoking in the home) explained the downward trend.

DESIGN

Trend analysis of repeat cross-sectional data from an annual nationally representative survey.

SETTING

New Zealand.

PARTICIPANTS

Secondary school students aged 14-15 (n=398 221).

OUTCOME MEASURE

Regular (at least monthly) smoking.

METHODS

For each risk factor (parental smoking, best friend smoking, older sibling smoking and past week exposure to smoking in the home) we plotted prevalence of exposure, 2002-2015. Next, using multivariable logistic regression, we modelled the trend in regular smoking (expressed as an OR for year) adjusting for age, sex, ethnicity and socioeconomic position. The risk factors were added to the model-individually and collectively-to test whether they attenuated the OR for year.

RESULTS

Exposure to all risk factors except 'past week exposure to smoking in the home' decreased between 2002 and 2015. We observed a strong downward trend in regular smoking among adolescents (OR=0.88 per year, 95% CI 0.88 to 0.88, p<0.001). 'Best friend smoking' was the only risk factor that significantly attenuated the trend. However, due to circularity, this factor provides an unsatisfactory explanation for population level smoking decline.

CONCLUSIONS

The established risk factors that we explored do not appear to have contributed to the remarkable decline in adolescent smoking in New Zealand between 2003 and 2015. Further research is needed to assess the possible contribution of factors outside our model, such as changes in the policy context, the social meaning of smoking and broader social and economic conditions.

Psychosocial perspective and suicidal behaviors correlated with adolescent male smoking and illicit drug use

OBJECTIVES

To assess the prevalence of smoking and drug use among adolescent boys, and to examine adolescents' psychosocial factors, and suicidal behaviors associated with adolescents' substance use.

METHODS

The Kuwait Global School-Based Student Health Survey employed a two-stage cluster sample design targeting a representative sample of adolescents. This study focused on the participated 1310 boys. Statistical analysis included Chi-square test, student t-test, and multivariate analysis.

RESULTS

The mean age was 14.5 ± 0.03 years. The reported prevalence of: smoking, ever drug use, and both smoking and drug use were 26.6% (95% CI:24.2-29.1%) and 7.4% (95% CI:6.1-9.0%) and 5.5% (95% CI:4.4-6.9%) respectively. Logistic regression model analysis revealed that adolescents whose parents smoke, suffered from insomnia, were victims of bullying, and had negative social school environment, were more likely than others to be smokers, drug users or both. Addendum, suicidal ideation, and its combination with suicidal planning and/or suicidal attempt were significantly associated with smoking. The odds of these life-threatening behaviors increased when drug use was reported and augmented when both smoking and drug use were experienced.

CONCLUSIONS

Prevalence of smoking and illicit drug use were high among adolescent boys. This study confirmed the association between adolescents' smoking and substance use with psychosocial context, and suicidal behaviors. Addressing these predictors would be crucial in the development of effective strategies targeting the prevention of smoking and substance use, which might consequently reduce suicidal behaviors among adolescents.

Prevalence and socioeconomic inequalities in indoor exposure to secondhand smoke at home among children 0-5years in Ghana

BACKGROUND

Daily exposure to secondhand smoke (ESHS) among children can be fatal for their health. With increasing prevalence of smoking in low-income countries, particularly among low socioeconomic status (SES) groups amidst poor tobacco legislations, children in these countries can be at risk of ESHS at home. This study investigated the prevalence and socioeconomic inequalities in indoor daily of ESHS at home among children aged 0-5years in Ghana.

METHODS

Population-based data collected through interviews in 2014 in 4616 households, 98.5% response rate, were used. Logistic regression analyses were used to investigate socioeconomic inequalities in daily ESHS among children at home.

RESULTS

One out of every ten children was exposed to daily secondhand smoke at home. The proportion of children's ESHS by wealth quintile ranges from richest (6.5%) to poorest (46.3%). Children of male-headed households were at higher risk of daily ESHS (OR 1.71, CI 1.27-2.31). A child living in a household where the head had no formal education had four folds the risk of daily ESHS compared with another in a household headed by a person with higher educational attainment. In rural setting, a child living in a poorest household (measured by wealth index) had more than two folds the risk of daily ESHS compared with another in the richest household. Correspondingly, a child living in the poorest household in an urban area had 8 times (OR 8.05, CI 4.03-16.08) the risk of daily ESHS compared with the counterpart in the richest household.

CONCLUSIONS

Children from socioeconomically disadvantaged and male-headed households both in rural and urban areas were at higher risk of daily ESHS at homes. However, children in the poorest households in urban areas had the highest concentration of ESHS among socioeconomically disadvantaged children. Interventions to end smoking indoors at home is urgently needed to protect children from its harmful effects.

Airborne Nicotine, Secondhand Smoke, and Precursors to Adolescent Smoking

BACKGROUND AND OBJECTIVES

Secondhand smoke (SHS) directly increases exposure to airborne nicotine, tobacco's main psychoactive substance. When exposed to SHS, nonsmokers inhale 60% to 80% of airborne nicotine, absorb concentrations similar to those absorbed by smokers, and display high levels of nicotine biomarkers. Social modeling, or observing other smokers, is a well-established predictor of smoking during adolescence. Observing smokers also leads to increased pharmacological exposure to airborne nicotine via SHS. The objective of this study is to investigate whether greater exposure to airborne nicotine via SHS increases the risk for smoking initiation precursors among never-smoking adolescents.

METHODS

Secondary students (N = 406; never-smokers: n = 338, 53% girls, mean age = 12.9, SD = 0.4) participated in the AdoQuest II longitudinal cohort. They answered questionnaires about social exposure to smoking (parents, siblings, peers) and known smoking precursors (eg, expected benefits and/or costs, SHS aversion, smoking susceptibility, and nicotine dependence symptoms). Saliva and hair samples were collected to derive biomarkers of cotinine and nicotine. Adolescents wore a passive monitor for 1 week to measure airborne nicotine.

RESULTS

Higher airborne nicotine was significantly associated with greater expected benefits (R² = 0.024) and lower expected costs (R² = 0.014). Higher social exposure was significantly associated with more temptation to try smoking (R² = 0.025), lower aversion to SHS (R² = 0.038), and greater smoking susceptibility (R² = 0.071). Greater social exposure was significantly associated with more nicotine dependence symptoms; this relation worsened with higher nicotine exposure (cotinine R² = 0.096; airborne nicotine R² = 0.088).

CONCLUSIONS

Airborne nicotine exposure via SHS is a plausible risk factor for smoking initiation during adolescence. Public health implications include limiting airborne nicotine through smoking bans in homes and cars, in addition to stringent restrictions for e-cigarettes.

The Difference a Decade Makes: Smoking Cessation Counseling and Screening at Pediatric Visits

INTRODUCTION

There has been a sharp decline in adolescents who smoke cigarettes but no national-level study evaluating the impact of smoking cessation counseling by pediatricians or other clinicians who care for children.

METHODS

Combined data from ambulatory portions of the National Hospital Ambulatory Care Survey and National Ambulatory Medical Care Survey from 1997-1999 and 2009-2011 were analyzed to determine changes in the frequency of pediatric visits that included clinician-reported tobacco counseling and how such counseling varied by child, family, and clinician characteristics.

RESULTS

In 1997-1999, 1.5% of all medical visits for children aged below 19 years included tobacco counseling; this increased to 3.8% in 2009-2011 (P < .001). A marked increase from 4.1% to 11.1% was noted at well-child visits (P < .001). There were significant increases in counseling by pediatricians but not mid-level providers or general/family physicians. Provision of counseling did not result in greater visit length during either time point. During 2009-2011, visits with a diagnosis of asthma were four times as likely (OR 4.2, 95% CI 2.8-6.2) and visits for otitis media two times as likely (OR 2.1, 95% CI 1.2-3.7) to include smoking cessation counseling than sick visits for all other diagnoses.

CONCLUSION

These results demonstrate a significant increase in tobacco counseling by pediatric providers within the last decade, especially at well-child visits. However, the American Academy of Pediatrics' recommendation that pediatricians counsel about the harms of tobacco use and secondhand smoke exposure has not yet been exhaustively implemented.

IMPLICATIONS

A significant increase in smoking cessation counseling at pediatric medical appointments, especially at well-child visits, occurred from 2009-2011 compared with 1997-1999, paralleling a large decrease in smoking prevalence. These improvements in counseling rates have been predominantly noted for pediatricians but not mid-level providers or general practitioners. Counseling was not associated with increased visit lengths. Although improved counseling practices by pediatricians have been demonstrated, there is still room for improvement.

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.

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.

Parental smoke exposure and the development of nicotine craving in adolescent novice smokers: the roles of DRD2, DRD4, and OPRM1 genotypes

BACKGROUND

Among adolescent novice smokers, craving is often the first, and is the most reported, symptom of nicotine dependence. Until now, little has been known about the development of craving symptoms in novice smokers. The aim of this study was to identify specific genetic (i.e., DRD2 Taq1A, DRD4 48 bp VNTR, and OPRM1 A118G polymorphisms) and environmental mechanisms that underlie the emergence of both cue-induced and cognitive craving among adolescent novice smokers.

METHOD

A five-wave longitudinal, genetically-informed survey study was conducted with intervals of four months. The sample included 376 early adolescent smokers (12-13 years of age at baseline). Self-report questionnaires were completed regarding smoking behavior, observed parental smoking behavior, and both cue-induced and cognitive craving.

RESULTS

Data were analyzed with a latent growth curve approach. For both cue-induced and cognitive craving, significant interaction effects were found for DRD2 Taq1A with parental smoke exposure. A1-allele carriers did not seem to be influenced by the environment with regard to craving development. Adolescents who are homozygous for the A2-allele and who are more exposed to parental smoking experience the highest levels of both types of craving over time. No significant interaction effects were found between parental smoke exposure and DRD4 48 bp VNTR or OPRM1 A118G.

CONCLUSIONS

Previous studies identified DRD2 Taq1A A1-allele carriers as vulnerable to developing nicotine dependence. However, this study showed that parental smoking increased the chances of developing dependence more rapidly for early adolescents who are considered to be less sensitive to the rewarding effects of nicotine according to their DRD2 Taq1A genotype. It is thus especially important that these young people not be exposed to smoking in their social environment.

Reducing Underserved Children's Exposure to Tobacco Smoke: A Randomized Counseling Trial With Maternal Smokers

INTRODUCTION

Addressing maternal smoking and child tobacco smoke exposure is a public health priority. Standard care advice and self-help materials to help parents reduce child tobacco smoke exposure is not sufficient to promote change in underserved populations. We tested the efficacy of a behavioral counseling approach with underserved maternal smokers to reduce infant's and preschooler's tobacco smoke exposure.

DESIGN

A two-arm randomized trial: enhanced behavior counseling (experimental) versus enhanced standard care (control). Assessment staff members were blinded.

SETTING/PARTICIPANTS

Three hundred randomized maternal smokers were recruited from low-income urban communities. Participants had a child aged <4 years exposed to two or more maternal cigarettes/day at baseline.

INTERVENTION

Philadelphia Family Rules for Establishing Smoke-free Homes (FRESH) included 16 weeks of counseling. Using a behavioral shaping approach within an individualized cognitive-behavioral therapy framework, counseling reinforced efforts to adopt increasingly challenging tobacco smoke exposure-protective behaviors with the eventual goal of establishing a smoke-free home.

MAIN OUTCOME MEASURES

Primary outcomes were end-of-treatment child cotinine and reported tobacco smoke exposure (maternal cigarettes/day exposed). Secondary outcomes were end-of-treatment 7-day point-prevalence self-reported cigarettes smoked/day and bioverified quit status.

RESULTS

Participation in FRESH behavioral counseling was associated with lower child cotinine (β=-0.18, p=0.03) and reported tobacco smoke exposure (β=-0.57, p=0.03) at the end of treatment. Mothers in behavioral counseling smoked fewer cigarettes/day (β=-1.84, p=0.03) and had higher bioverified quit rates compared with controls (13.8% vs 1.9%, χ(2)=10.56, p<0.01). There was no moderating effect of other smokers living at home.

CONCLUSIONS

FRESH behavioral counseling reduces child tobacco smoke exposure and promotes smoking quit rates in a highly distressed and vulnerable population.

TRIAL REGISTRATION

This study is registered at www.clinicaltrials.gov NCT02117947.

Secondhand smoke exposure and other correlates of susceptibility to smoking: a propensity score matching approach

Secondhand smoke (SHS) exposure is responsible for numerous diseases of the lungs and other bodily systems among children. In addition to the adverse health effects of SHS exposure, studies show that children exposed to SHS are more likely to smoke in adolescence. Susceptibility to smoking is a measure used to identify adolescent never-smokers who are at risk for smoking. Limited research has been conducted on the influence of SHS on susceptibility to smoking. The purpose of this study was to determine a robust measure of the strength of correlation between SHS exposure and susceptibility to smoking among never-smoking U.S. adolescents. This study used data from the 2009 National Youth Tobacco Survey to identify predictors of susceptibility to smoking in the full (pre-match) sample of adolescents and a smaller (post-match) sample created by propensity score matching. Results showed a significant association between SHS exposure and susceptibility to smoking among never-smoking adolescents in the pre-match (OR=1.47) and post-match (OR=1.52) samples. The odds ratio increase after matching suggests that the strength of the relationship was underestimated in the pre-match sample. Other significant correlates of susceptibility to smoking identified include: gender, race/ethnicity, personal income, smoke-free home rules, number of smoking friends, perception of SHS harm, perceived benefits of smoking, and exposure to pro-tobacco media messages. The use of propensity score matching procedures reduced bias in the post-match sample, and provided a more robust estimate of the influence of SHS exposure on susceptibility to smoking, compared to the pre-match sample estimates.

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.

Early childhood predictors of early onset of smoking: a birth prospective study

OBJECTIVE

Early onset of smoking is associated with subsequent abuse of other substances and development of negative health outcomes. This study aimed to examine early life predictors of onset of smoking in an Australian young cohort.

METHODS

Data were from the Mater Hospital and University of Queensland Study of Pregnancy (MUSP), a population-based prospective birth cohort study (1981-2012). The present study is based on a cohort of 3714 young adults who self-reported smoking status and age of onset of smoking at the 21-year follow-up. Of these, data were available for 3039 on early childhood factors collected between the baseline and 14-year follow-up of the study.

RESULTS

Of 3714 young adults, 49.6% (49.9% males and 49.3% females) reported having ever smoked cigarettes. For those who had ever smoked, mean and median ages at first smoke were 15.5 and 16.0years, respectively. In multivariate Cox proportional hazard analysis mother's education, change in maternal marital status, maternal cigarette smoking and alcohol consumption, maternal depression and child externalizing when the child was 5years statistically significantly predicted early onset of smoking.

CONCLUSIONS

The data suggest that individuals exposed to personal and environmental risk factors during the early stage of childhood are at increased risk of initiation to cigarette smoking at an earlier age. Identification of the pathways of association between these early life factors and initiation to cigarette smoking may help reduce risk of tobacco smoking in adolescents and its adverse consequences.

Brief intervention to preteens and adolescents to create smoke-free homes and cotinine results: a randomized trial

BACKGROUND

Little research has focused on brief and practical strategies for addressing environmental tobacco smoke exposure through interventions focused explicitly on creating a smoke-free home.

METHODS

We used a two-group (intervention and control groups) repeated-measures randomized controlled trial design. Families were randomized to the intervention (n = 176) or control (n = 176) condition after the baseline interview, with outcome assessments for reported and urine cotinine measures at 2 (post-intervention), 6 (follow-up) and 12 (follow-up) months.

RESULTS

Baseline urinary cotinine levels of both groups were not statistically significantly different (P > 0.05); however, post-intervention urinary cotinine levels were significantly different at 2, 6 and 12 months after start of the study (P < 0.001).

CONCLUSION

As a physician-based brief intervention, our intervention was effective. Clinical providers might offer feedback and brief interventions to preteens and adolescents. Because of the ease of intervention on delivery, this intervention has the potential to have significant impact if widely disseminated.

Smoking restrictions in the homes of children with cancer

OBJECTIVES

To examine smoking restrictions in households of children with cancer and their effect on biological measures of children's secondhand smoke exposure (SHSe).

METHODS

A sample of 135 parents of nonsmoking children with cancer who lived with a smoker completed structured interviews.

RESULTS

Approximately 43% of families prohibited smoking in the home. Children living in homes that prohibited smoking had median cotinine levels that were 71% and 52% lower than did those from homes with no and partial restrictions.

CONCLUSIONS

Parents should be directed to completely ban all smoking from the home and car to best protect their children from SHSe.

Animal models of nicotine exposure: relevance to second-hand smoking, electronic cigarette use, and compulsive smoking

Much evidence indicates that individuals use tobacco primarily to experience the psychopharmacological properties of nicotine and that a large proportion of smokers eventually become dependent on nicotine. In humans, nicotine acutely produces positive reinforcing effects, including mild euphoria, whereas a nicotine abstinence syndrome with both somatic and affective components is observed after chronic nicotine exposure. Animal models of nicotine self-administration and chronic exposure to nicotine have been critical in unveiling the neurobiological substrates that mediate the acute reinforcing effects of nicotine and emergence of a withdrawal syndrome during abstinence. However, important aspects of the transition from nicotine abuse to nicotine dependence, such as the emergence of increased motivation and compulsive nicotine intake following repeated exposure to the drug, have only recently begun to be modeled in animals. Thus, the neurobiological mechanisms that are involved in these important aspects of nicotine addiction remain largely unknown. In this review, we describe the different animal models available to date and discuss recent advances in animal models of nicotine exposure and nicotine dependence. This review demonstrates that novel animal models of nicotine vapor exposure and escalation of nicotine intake provide a unique opportunity to investigate the neurobiological effects of second-hand nicotine exposure, electronic cigarette use, and the mechanisms that underlie the transition from nicotine use to compulsive nicotine intake.

Responses to environmental smoking in never-smoking children: can symptoms of nicotine addiction develop in response to environmental tobacco smoke exposure?

A recent line of studies has brought attention to the question whether repeated exposure to environmental tobacco smoke (ETS) is capable of producing psycho-physiological effects in non-smokers and whether symptoms of nicotine dependence can develop in the absence of active smoking. Children seem to be particularly vulnerable to the effects of ETS. We examined the occurrence of psycho-behavioural symptoms, designed to assess nicotine addiction and nicotine withdrawal, in a sample of 778 never-smoking children aged 9-12 years using cross-sectional survey data collected in 15 Dutch primary schools. In the present study, 6% of never-smoking children reported symptoms of craving, 8% reported cue-triggered wanting to smoke, and 20% reported subjective symptoms in response to ETS exposure. In never-smoking children, a higher number of smokers in the child's social environment was associated with more symptoms of cue-triggered wanting to smoke and more subjective symptoms in response to ETS. Never-smoking children and children who had initiated smoking were equally likely to report subjective symptoms in response to ETS exposure. In conclusion, environmental smoking is associated with self-reported psycho-behavioural symptoms in never-smoking children. Future research needs to investigate whether symptoms in children exposed to ETS are physiologically based or whether they reflect other characteristics which predispose youth for smoking initiation in the future.

A systematic review of the relationships between family functioning, pubertal timing and adolescent substance use

AIMS

Experiences linked to poor family functioning and pubertal timing have each been associated with increased risk of substance misuse in adolescence. However, it remains unclear to what extent family functioning and pubertal timing combine to put adolescents at particular risk.

METHOD

A systematic review was planned, undertaken and reported according to the 27 items of the PRISMA statement. Databases World of Knowledge, PsycINFO and PubMed were searched. Fifty-eight papers were retained and are discussed in this review after screening titles, abstracts and full papers against pre-established exclusion criteria.

RESULTS

The combination of off-time pubertal timing and poor parent-adolescent relationship quality has been related to higher levels of substance use. However, this is an under-studied area of research and the evidence is less strong for boys than girls.

CONCLUSIONS

Adolescents experiencing both poor parent-adolescent relationship quality and off-time pubertal timing may represent a high-risk group that can benefit from approaches aimed at reducing risk of substance misuse.

The role of environmental smoking in smoking-related cognitions and susceptibility to smoking in never-smoking 9-12 year-old children

Environmental smoking has numerous adverse effects on child health, and children are frequently exposed to environmental smoking. In the present study, we investigated the role of environmental smoking (parental smoking, sibling smoking, peer smoking) in smoking-related cognitions (pros of smoking, perceived safety of casual smoking, cue-triggered wanting to smoke) and susceptibility to smoking among 9-12 year old never-smoking children (N=778). We collected cross-sectional survey data from children attending 15 Dutch primary schools. Using structural equation modelling, we assessed direct as well as indirect relationships among study variables. The results showed that children who were exposed to more smoking parents, siblings, and peers perceived more pros of smoking. Additionally, parental smoking was associated with higher perceived safety of casual smoking and more cue-triggered wanting to smoke. In turn, perceiving a higher safety of casual smoking and more cue-triggered wanting to smoke were associated with a higher susceptibility to smoking in children. No direct effects of environmental smoking on children's susceptibility to smoking were found. However, parental smoking was associated with children's susceptibility to smoking through children's perceived safety of casual smoking and cue-triggered wanting to smoke. The present study indicates that pre-adolescents may already display favourable smoking-related cognitions and that these cognitions may be an early indicator of a child's vulnerability to smoking. Environmental smoking, particularly parental smoking, is associated with more favourable smoking-related cognitions in never-smoking children. In the intergenerational transmission of smoking from parents to children, children's risk perceptions of smoking and the experience of cue-triggered wanting to smoke may constitute mechanisms of action, which need to be investigated in longitudinal research.

Social, psychological, and environmental-structural factors associated with tobacco experimentation among adolescents in Shanghai, China

OBJECTIVE

To estimate the prevalence and social, psychological and environmental-structural determinants of tobacco experimentation among adolescents in Shanghai, China.

METHODS

We conducted a cross-sectional study based on a two-stage cluster sample design by using the Chinese version of the Global Youth Tobacco Survey (GYTS) to investigate smoking behavior among 19,117 students from 41 junior and senior high schools in Shanghai, China. The association between potential factors and tobacco experimentation were assessed using complex samples procedure logistic regression.

RESULTS

Of the 19,117 respondents, 10.5% (15.3% boys and 6.2% girls) reported the tobacco experimentation. The main social, psychological, and environmental-structural factors associated with tobacco experimentation were having close friends who smoke (AOR = 8.21; 95% CI: 6.49-10.39); one or both parents smoking (AOR 1.57; CI: 1.39-1.77); a poor school tobacco control environment (AOR 1.53; CI: 1.37-1.83); a high acceptance level of tobacco use (AOR 1.44; CI: 1.28-1.82); and a high level of media tobacco exposure (AOR 1.23; CI: 1.10-1.37). Peer smoking might contribute to smoking experimentation among girls (AOR 8.93; CI: 5.84-13.66) more so than among boys (AOR 7.79; CI: 5.97-9.94) and media tobacco exposure had no association with tobacco experimentation among female students.

CONCLUSIONS

Social, psychological, and environmental factors are closely associated with tobacco experimentation among adolescents. Prevention programs aimed at reducing teen tobacco experimentation should be conducted at home and school with support by parents, peers and teachers. Our findings should prove useful for future development of intervention strategies among adolescents in Shanghai, China.

Association between environmental tobacco smoke exposure of children and parental socioeconomic status: a cross-sectional study in Korea

INTRODUCTION

It has been reported that most environmental tobacco smoke (ETS) exposure of children occurs at home, and lower parental socioeconomic status (SES) increases the risk of this exposure. We estimated the independent and interactive effects of parental SES and residential area SES on ETS exposure of children at home.

METHODS

We evaluated whether ETS exposure was associated with parental SES by entering data from 7,059 school-aged children in Korea into fixed effects models. The empirical model, including the interaction variable of the level of deprivation of each residential area, was fitted with parental SES.

RESULTS

After adjustment for possible confounding variables, low paternal education (odds ratio [OR], 1.81; 95% CI, 1.30-2.54) and highly deprived areas (OR, 1.34; 95% CI, 1.06-1.69) were significantly associated with the ETS exposure of children, especially among children whose fathers had <12 years of education and lived in the most deprived area (OR, 2.04; 95% CI, 1.04-4.02).

CONCLUSIONS

Our findings suggest that the SES of residential areas may influence the ETS exposure of children directly, as well as interactively with parental SES, in Korea. Findings from this study will help inform policy decision makers that intervention to promote smoking cessation should consider not only the SES of individuals but also that of residential areas.

Providing coaching and cotinine results to preteens to reduce their secondhand smoke exposure: a randomized trial

BACKGROUND

Secondhand smoke exposure (SHSe) poses health risks to children living with smokers. Most interventions to protect children from SHSe have coached adult smokers. This trial determined whether coaching and cotinine feedback provided to preteens can reduce their SHSe.

METHODS

Two hundred one predominantly low-income families with a resident smoker and a child aged 8 to 13 years who was exposed to two or more cigarettes per day or had a urine cotinine concentration ≥ 2.0 ng/mL were randomized to control or SHSe reduction coaching groups. During eight in-home sessions over 5 months, coaches presented to the child graphic charts of cotinine assay results as performance feedback and provided differential praise and incentives for cotinine reductions. Generalized estimating equations were used to determine the differential change in SHSe over time by group.

RESULTS

For the baseline to posttest period, the coaching group had a greater decrease in both urine cotinine concentration (P = .039) and reported child SHSe in the number of cigarettes exposed per day (child report, P = .003; parent report, P = .078). For posttest to month 12 follow-up, no group or group by time differences were obtained, and both groups returned toward baseline.

CONCLUSIONS

Coaching preteens can reduce their SHSe, although reductions may not be sustained without ongoing counseling, feedback, and incentives. Unlike interventions that coach adults to reduce child SHSe, programs that increase child avoidance of SHSe have the potential to reduce SHSe in all settings in which the child is exposed, without requiring a change in adult smoking behavior.

Sensitivity to secondhand smoke exposure predicts future smoking susceptibility

OBJECTIVE

Susceptibility to cigarette smoking in tobacco-naive youth is a strong predictor of smoking initiation. Identifying mechanisms that contribute to smoking susceptibility provide information about early targets for smoking prevention. This study investigated whether sensitivity to secondhand smoke exposure (SHSe) contributes to smoking susceptibility.

PARTICIPANTS AND METHODS

Subjects were high-risk, ethnically diverse 8- to 13-year-old subjects who never smoked and who lived with at least 1 smoker and who participated in a longitudinal SHSe reduction intervention trial. Reactions (eg, feeling dizzy) to SHSe were assessed at baseline, and smoking susceptibility was assessed at baseline and 3 follow-up measurements over 12 months. We examined the SHSe reaction factor structure, association with demographic characteristics, and prediction of longitudinal smoking susceptibility status.

RESULTS

Factor analysis identified "physically unpleasant" and "pleasant" reaction factors. Reported SHSe reactions did not differ across gender or family smoking history. More black preteens reported feeling relaxed and calm, and fewer reported feeling a head rush or buzz compared with non-Hispanic white and Hispanic white counterparts. Longitudinally, 8.5% of subjects tracked along the trajectory for high (versus low) smoking susceptibility. Reporting SHSe as "unpleasant or gross" predicted a 78% reduction in the probability of being assigned to the high-smoking susceptibility trajectory (odds ratio: 0.22 [95% confidence interval: 0.05-0.95]), after covariate adjustment.

CONCLUSIONS

Assessment of SHSe sensitivity is a novel approach to the study of cigarette initiation etiology and informs prevention interventions.

Relationship between smoking and family history of smoking in schizophrenia patients

BACKGROUND

The rate of smoking is known to be high in patients with schizophrenia. The purpose of this study was to quantitatively examine the relationship between smoking and family history of smoking in patients with schizophrenia.

METHODS

The sample consisted of 172 patients (mean age: 54 years, 55% male) hospitalized in a general psychiatric hospital. They were asked by a physician whether they smoked. Family histories of smoking and schizophrenia were assessed among first- and third-degree relatives.

RESULTS

Ninety-eight patients (57%) were identified as having smoked at some point. Multiple logistic regression analysis showed that smoking was significantly associated with family histories of smoking among both first- and third-degree relatives, controlling for the effects of age, sex, and family history of schizophrenia. The smoking rates were significantly higher in those with a family history of smoking, but not a family history of schizophrenia, than among those without a family history of either smoking or schizophrenia. However, this difference did not reach statistical significance among those with a family history of schizophrenia.

CONCLUSION

Smoking is greatly influenced by family history of smoking in patients with schizophrenia, especially among those without a family history of schizophrenia. The association between smoking and family history of smoking was inconclusive among those patients with schizophrenia who also had a family history of schizophrenia.

An investigation of social and pharmacological exposure to secondhand tobacco smoke as possible predictors of perceived nicotine dependence, smoking susceptibility, and smoking expectancies among never-smoking youth

INTRODUCTION

Recent studies evidenced that adolescent never-smokers exposed to secondhand tobacco smoke (SHS) endorsed nicotine dependence symptoms. Other studies showed that SHS exposure measured with biomarkers among never-smokers independently predicted withdrawal sensations and prospective smoking initiation. The aim of the present study was to replicate and extend these findings by investigating whether social and pharmacological measures of SHS exposure predicted precursors to smoking among never-smoking adolescents.

METHODS

Participants included 327 never-smokers aged 11-15 years attending sixth or seventh grade in French language schools in Montréal, Canada. They completed self-report questionnaires measuring their smoking status, social smoke exposure (number of smokers in their environment and number of situations where SHS exposure occurs), and precursors to smoking initiation (smoking expectancies, perceived nicotine dependence, and smoking susceptibility). Each participant provided a saliva sample from which cotinine biomarkers were derived to measure pharmacological exposure to SHS.

RESULTS

When predictors were modeled individually, number of smokers predicted perceived nicotine dependence (p ≤ .05), smoking susceptibility (p ≤ .001), and expected benefits (p ≤ .05), whereas number of situations predicted smoking susceptibility (p ≤ .01). When predictors were modeled simultaneously, number of smokers predicted perceived nicotine dependence (p ≤ .01), smoking susceptibility (p ≤ .01), and expected benefits (p ≤ .05).

CONCLUSIONS

Social smoke exposure was a predictor for smoking precursors. Pharmacological exposure to SHS did not predict smoking precursors, which may be partly attributable to the low cotinine values observed in our sample. Suggestions for improved pharmacological measurement of SHS and implications for public health are discussed.

Effect of secondhand smoke on occupancy of nicotinic acetylcholine receptors in brain

CONTEXT

Despite progress in tobacco control, secondhand smoke (SHS) exposure remains prevalent worldwide and is implicated in the initiation and maintenance of cigarette smoking.

OBJECTIVE

To determine whether moderate SHS exposure results in brain α(4)β(2)* nicotinic acetylcholine receptor (nAChR) occupancy.

DESIGN, SETTING, AND PARTICIPANTS

Positron emission tomography scanning and the radiotracer 2-[18F]fluoro-3-(2(S)azetidinylmethoxy) pyridine (also known as 2-[(18)F]fluoro-A-85380, or 2-FA) were used to determine α(4)β(2)* nAChR occupancy from SHS exposure in 24 young adult participants (11 moderately dependent cigarette smokers and 13 nonsmokers). Participants underwent two bolus-plus-continuous-infusion 2-FA positron emission tomography scanning sessions during which they sat in the passenger's seat of a car for 1 hour and either were exposed to moderate SHS or had no SHS exposure. The study took place at an academic positron emission tomography center. Main Outcome Measure  Changes induced by SHS in 2-FA specific binding volume of distribution as a measure of α(4)β(2)* nAChR occupancy.

RESULTS

An overall multivariate analysis of variance using specific binding volume of distribution values revealed a significant main effect of condition (SHS vs control) (F(1,22) = 42.5, P < .001) but no between-group (smoker vs nonsmoker) effect. Exposure to SHS led to a mean 19% occupancy of brain α(4)β(2)* nAChRs (1-sample t test, 2-tailed, P < .001). Smokers had both a mean 23% increase in craving with SHS exposure and a correlation between thalamic α(4)β(2)* nAChR occupancy and craving alleviation with subsequent cigarette smoking (Spearman ρ = -0.74, P = .01).

CONCLUSIONS

Nicotine from SHS exposure results in substantial brain α(4)β(2)* nAChR occupancy in smokers and nonsmokers. Study findings suggest that such exposure delivers a priming dose of nicotine to the brain that contributes to continued cigarette use in smokers. This study has implications for both biological research into the link between SHS exposure and cigarette use and public policy regarding the need to limit SHS exposure in cars and other enclosed spaces.

Sensitivity to secondhand smoke exposure predicts smoking susceptibility in 8-13-year-old never smokers

PURPOSE

To investigate the sensitivity to secondhand smoke exposure (SHSe) in preteens aged 8-13 years who have never smoked, and to determine whether it predicts smoking susceptibility.

METHODS

We assessed the sensitivity to SHSe using reactions commonly used for the assessment of sensitivity to the first-smoked cigarette (e.g., feeling dizzy), and investigated the factor structure of these reactions for the purpose of data reduction. We examined the association of each reaction measure and summary score with demographic characteristics and smoking susceptibility, using logistic regression and ordinal logistic regression.

RESULTS

One factor was identified that captured the physical and/or unpleasant reactions. Older preteens and preteens with more highly educated parents reported fewer reactions to SHSe. More African American preteens reported feeling relaxed or calm compared with all other racial/ethnic groups. Experiencing physical and/or unpleasant reactions to SHSe predicted lower risk for smoking susceptibility.

CONCLUSIONS

This was the first study to extend analytical methodology for sensitivity to active smoking to sensitivity to SHSe in youth who had never smoked. Results suggest a desensitization process with age and lower sensitivity to some reactions in preteens from more highly educated households. Preteens who have more aversive experiences with SHSe tend to be less susceptible to smoking than those who experience fewer aversive reactions. Assessment of sensitivity to SHSe is a novel approach to the study of cigarette use etiology and may contribute to better prediction of smoking initiation.

'I just saw it as something that would pull you down, rather than lift you up': resilience in never-smokers with mental illness

Why people smoke despite the health risks is an important public health question. Equally important is why and how some people resist smoking in spite of circumstances that clearly place them at high risk of becoming smokers. This study used in-depth interviews to explore the narratives of 12 people diagnosed with mental illness, who had made conscious decisions not to smoke. This was despite most of them growing up in smoking families or being from population groups at high risk of smoking. A qualitative grounded theory methodology was used to analyse common themes around protective behaviours and attitudes within a model of resilience. Themes included strong negative reactions to smoking as children which have persisted into adulthood, strong lasting associations with smoking, a clear sense of 'self' separate from peers from an early age (internal resilience) and developing a range of coping strategies and external supports not related to smoking (external resilience). Understanding resilience holds potential lessons for health promotion and primary health care professionals supporting the prevention of smoking uptake and supporting smoking cessation by at risk groups.

Secondhand smoke avoidance by preteens living with smokers: to leave or stay?

INTRODUCTION

Secondhand smoke (SHS) is hazardous to children's health. Designing interventions to reduce exposure requires understanding children's behavior in the presence of smokers, yet little is known about this behavior.

PURPOSE

To determine whether children's avoidance of SHS is associated with lower exposure and to explore predictors of avoidance based on a behavioral ecological model.

METHOD

Preteens aged 8-13 (N=358) living with a smoker identified their primary source of SHS exposure, and reported whether they left (avoided exposure) or stayed the last time they were exposed to that person's smoke. The SHS avoidance measure was validated by examining associations with SHS exposure. Multiple Logistic Regression was used to determine predictors of SHS avoidance.

RESULTS

Based on urine cotinine and reported exposure, preteens who left the presence of SHS had lower exposure than those who stayed. Preteens were more likely to leave SHS if they were less physically mature, had not tried smoking, had a firm commitment not to smoke, did not assist family smoking, had family/friends who discouraged breathing SHS, or had friends who disliked smoking.

DISCUSSION

Most SHS exposure reduction interventions have targeted changes in smokers' behavior. Reductions can also be achieved by changing exposed nonsmokers' behavior, such as avoiding the exposure. Future studies should measure young people's SHS avoidance and test interventions to increase their avoidance practices.

Correlates of smoking among adolescents with asthma

AIMS AND OBJECTIVE

This study examined the correlates of smoking among asthmatic adolescents to gain a better understanding of who is at particular risk.

BACKGROUND

Smoking is especially harmful to individuals with asthma. However, smoking is surprisingly prevalent among asthmatic individuals, with prevalence rates similar to or higher than those of the general adult or adolescent populations. Despite this notable finding, there has been little research about factors (i.e. biophysical, psychosocial and behavioural) influencing asthmatic adolescents' tobacco use patterns.

DESIGN

A Canadian provincial cross-sectional survey.

METHOD

The study about adolescents' tobacco use and health status was conducted in secondary schools in 2004, 608 asthmatic adolescents participated. Demographic factors, biophysical (body mass index and physical health), psychosocial factors (parents' and peers' smoking, environmental tobacco smoke exposure and depression) and behavioural factors (marijuana use, alcohol use and exercise frequency) were explored. Multinomial logistic regression analyses were conducted to identify risk factors associated with tobacco use.

RESULTS AND CONCLUSIONS

Of the 608 asthmatic adolescents, 17.4% currently smoked and 12.0% formerly smoked. Girls, compared with boys, were more likely to smoke (OR: 3.34, 95% CI: 1.62-6.96) after adjusting for differences in the other demographic, biophysical, psychosocial and behavioural factors. Asthmatic girls who had relatively higher body mass index, were in the higher school grades, used marijuana or alcohol, had minor to severe depressive symptoms, had environmental tobacco smoke exposure in their homes and had friends who smoked or were currently more likely to smoke. The former smokers had similar risk factors including higher body mass index, environmental tobacco smoke exposure at home, friends who smoked and marijuana use.

RELEVANCE TO CLINICAL PRACTICE

Despite their health condition, asthmatic adolescents continue currently or formerly to smoke. Gender appropriate prevention and cessation interventions for asthmatic adolescents may need to address important psychosocial and environmental factors that increase the risk of these adolescents initiating and maintaining tobacco use.

Non-smoking youths' "perceived" addiction to tobacco is associated with their susceptibility to future smoking

Smoking initiation places adolescents at risk for adult onset diseases, including heart disease, respiratory illness, and cancer. Adolescents that smoke have levels of 'perceived' tobacco addiction that are associated with several measures of nicotine dependence. Nonsmoking adolescents also report feeling addicted to tobacco even with minimal or no prior tobacco use, suggesting some vulnerability to tobacco use. The purpose of this study was to examine the association between perceived tobacco addiction and smoking susceptibility among adolescents with very minimal tobacco use. A cross-sectional analysis was conducted of data obtained from 5155 nonsmokers who completed the British Columbia Youth Survey of Smoking and Health II, a school-based survey conducted during 2004. Measures included demographics, tobacco use (ever puffed a cigarette), substance use (marijuana and alcohol), exposure to family members' smoking in the home, peers' tobacco use, depressive symptoms, perceived physical and mental addiction to tobacco, and smoking susceptibility. The adolescents who were most susceptible to smoking were female, younger and in a lower school grade; had ever puffed a cigarette, had used alcohol or marijuana; had family members or peers who smoked; had higher depression scores, and higher perceived physical and mental addiction to tobacco. In multivariate logistic regression analysis, perceived mental addiction but not perceived physical addiction to tobacco was significantly associated with smoking susceptibility. Understanding factors associated with smoking initiation, and ways to identify "at- risk" adolescents can enhance early intervention and prevention programs. Perceived mental addiction to tobacco appears to be an important indicator of smoking susceptibility.

The behavioral ecology of secondhand smoke exposure: A pathway to complete tobacco control

INTRODUCTION

This article outlines a theoretical framework for research concerning secondhand smoke exposure (SHSe) prevention as a means to curtail the tobacco industry.

METHODS

The Behavioral Ecological Model (BEM) assumes interlocking social contingencies of reinforcement (i.e., rewards or punishments) from the highest level of society (e.g., taxing cigarette sales) to physiological reactions to nicotine that influence smoking and SHSe. We review selected research concerning both policy and clinical efforts to restrict smoking and/or SHSe.

RESULTS

Research to date has focused on smoking cessation with modest to weak effects. The BEM and empirical evidence suggest that cultural contingencies of reinforcement should be emphasized to protect people from SHSe, especially vulnerable children, pregnant women, the ill, the elderly, and low-income adults who have not "elected" to smoke. Doing so will protect vulnerable populations from industry-produced SHSe and may yield more and longer-lasting cessation.

CONCLUSIONS

Interventions that reduce SHSe may serve as a Trojan horse to counter the tobacco industry. Future studies should: (a) guide policies to restrict SHSe; (b) develop powerful community and clinical interventions to reduce SHSe; (c) test the degree to which policies and other contexts enhance the effects of clinical interventions (e.g., media programs disclosing the disingenuous marketing by the industry); and (d) investigate the effects of all health care providers' ability to reduce SHSe and generate an antitobacco culture, by advising all clients to avoid starting to smoke, to protect their children from SHSe, and to quit smoking.

The effect of smoking on allogeneic transplant outcomes

Using the Center for International Blood and Marrow Transplant Research (CIBMTR) data, we compared the transplant outcomes of patients with chronic myelogenous leukemia (CML) who were nonsmokers (NS) and past or current smokers (PCS). There were 2193 NS and 625 PCS who received matched sibling and unrelated donor allografts for CML in first chronic phase. We looked for dose effects and identified low and high dose smoking groups (>10 pack years, >1 pack per day). Outcomes were adjusted for known prognostic variables including the European Group for Blood and Marrow Transplant (EBMT) risk score. In multivariate analyses of sibling allograft recipients, relapse risk (RR) was higher (RR=1.67, P=.003) in smokers than NS, but the dose effects were not consistent. High-dose smokers experienced a 50% treatment-related mortality (TRM) versus 28% in the NS group at 5 years on univariate analysis, and the RR was 1.57 (P=.005) on multivariate analysis. Overall survival (OS) at 5 years was 68% in NS versus 62% in the low-dose smoking group versus 50% in the high-dose smoking group (P < .001). Smoking did not significantly affect outcomes in unrelated donor recipients, but numbers were smaller. High-dose smoking is associated with a reduction in OS in patients having sibling allografts for CML. A prospective study with detailed demographic, pulmonary function, and quality-of-life data would improve our understanding of this issue.

Nicotine dependence symptoms among young never-smokers exposed to secondhand tobacco smoke

BACKGROUND

To extend previous observations that secondhand tobacco smoke (SHS) is associated with nicotine markers in children, we investigated if SHS exposure is associated with self-reports of nicotine dependence (ND) symptoms among young never-smokers.

METHOD

Data on number of persons who smoke inside the home, number of days exposed to SHS in a motor vehicle in the past week, number of parents, siblings, and friends who smoke, and ND symptoms, were collected from 10-12 year-old students in self-report questionnaires. The association between SHS and ND symptoms among young never-smokers was assessed in logistic regression models.

RESULTS

Sixty-nine of 1488 never-smokers (5%) reported one or more ND symptom. After controlling for sibling and peer smoking, and susceptibility to initiating smoking, exposure to SHS in a motor vehicle was independently associated with ND symptoms (OR, 95% CI=1.2, 1.0-1.4). The OR for number of persons who smoke inside the home was 1.1 (0.9-1.4).

CONCLUSION

SHS exposure in motor vehicles may be associated with ND symptoms among young never-smokers. If replicated, this finding provides support for interventions that promote non-smoking in motor vehicles.

Smoking and related factors of the social environment among adolescents in the Republic of Karelia, Russia in 1995 and 2004

BACKGROUND

To investigate changes in smoking prevalence associated with social factors and existing health policies among adolescents in Russia from 1995 to 2004.

METHODS

In 1995 and 2004 a confidential questionnaire was distributed to every 9th grade student of all 10 comprehensive schools of the Pitkäranta in Republic of Karelia, Russia. In 1995, 385 children participated in the survey (response rate 95%) and 395 children (response rate 85%) in 2004.

RESULTS

Twenty-nine percent of boys smoked daily in 1995 and 31% in 2004. Daily smoking doubled from 7% to 15% for girls. Smoking in the schoolyard increased among girls. The proportion of girls who reported smoking at home with their parents' knowledge increased. Both genders cited the ease of purchasing tobacco as a minor. Knowledge about the fast development of tobacco addiction increased statistically significantly among boys. Fewer numbers of respondents of either gender thought that young smokers look 'cool' and more grown up. Having a best friend who smoked was the strongest predictor for smoking for both genders.

CONCLUSION

Smoking has increased among girls. Social environment is a predisposing factor. Anti-smoking legislation was implemented weakly. Minors purchase tobacco relatively easily. Knowledge about tobacco's harmfulness has somewhat increased but is not sufficient to deter starting smoking, especially among non-smoking girls. Adequate education of adolescents on the hazards of tobacco consumption is needed, accompanied by a more determined enforcement of health policies. The potent influence of peers should be considered when planning preventive interventions.

An examination of the relationship between adolescents' initial smoking experience and their exposure to peer and family member smoking

Sensitivity to the initial smoking experience, upon initial smoking experimentation, is associated with youth smoking. We determined the association between exposure to smoking from peers and family members on the symptoms of the initial smoking experience of adolescents. Data from a survey of 3280 high school students in the British Columbia, Canada were obtained; including information on demographics, tobacco use history, symptoms of initial smoking experience, and the smoking behaviours of peers and family member's (from which an 'exposure to smoking from peers and family members' variable was created). In multivariate logistic regression models, individuals with higher scores on the 'exposure to smoking from peers and family members' variable were more likely to report positive symptoms of initial smoking experience, even after controlling for confounding variables. Higher scores on the 'exposure to smoking from peers and family members' variable was associated with increased 'initial smoking experience' scores. Initial smoking experience scores (i.e. total number of reported initial symptoms) weakly mediated the relationship between exposure to smoking from peers and family members and current smoking. The present findings suggest that exposure to smoking from peers and family members may be an important factor to consider in understanding youths initial smoking experiences.

[Lung function and exposure to tobacco smoke among adolescents]

OBJECTIVE

To study lung function in adolescents in relation to smoking (active and passive smokers) and to investigate the repercussion on spirometric parameters.

PATIENTS AND METHOD

We studied 301 healthy adolescents with no history of bronchial asthma or colds in the month prior to the study. A questionnaire on tobacco exposure was administered and spirometry (Datospir-92) was performed.

RESULTS

There were 165 boys (54.5%) and 136 girls (45.5%) aged between 14 and 20 years old (16.40+/-1.32). A total of 27.2% were non-smokers and were not exposed to tobacco smoke (NS), 31.3% were passive smokers, with household exposure of 10 cigarettes per day during at least the previous year (PS), and 41.5% were current smokers who had been smoking>or=10 cigarettes/day for at least 1 year (CS). Significant differences were found between age and smoking habits (p=0.0001) and between smoking habits and female sex (girls CS: 33.9% vs boys CS: 21.8 %) (p=0.007). A significant association was found between smoking (NS, PS and CS) and spirometric parameters (ANOVA): forced vital capacity (FVC) (p=0.001), forced expiratory volume in 1 second (FEV1) (p=0.0001), FEV1/FVC (p=0.004), peak expiratory flow (PEF) (p=0.0001), midexpiratory flow at 25% of forced vital capacity (MEF25%) (p=0.01), MEF50% (p=0.0001) and MEF25-75% (p=0.0001); CS in relation to NS was as follows: FEV1, PEF, MEF50%, MEF25-50% (p=0.0001) and FVC, FEV1/FVC, MEF25% (p=0.01); CS in relation to PS: FEV1/ FVC (p=0.02), PEF (p=0.004), MEF50% and MEF25-75% (p=0.003), PS in relation to NS: FVC and FEV1 (p=0.02). Significant differences in FVC, FEV1 and MEF25-75% were found in female CS in comparison with boys.

CONCLUSIONS

The CS group showed a significant decrease in spirometric parameters in relation to the NS group. The airway was affected sooner in the female group of smokers than in the male group, even though the intensity and time of exposure were the same in both groups.

Factors influencing openness to future smoking among nonsmoking adolescents

BACKGROUND

To investigate the correlates of youth tobacco use in terms of nonsmoking adolescents' openness to future smoking, a secondary analysis of the 2000 and 2004 Indiana Youth Tobacco Survey (IYTS) was conducted.

METHODS

A representative sample of 1416 public high school students in grades 9-12 and 1516 public middle school students in grades 6-8 (71.44% and 72.53% response rates, respectively) were surveyed in 2000, and 3433 public high school students and 1990 public middle school students (63.04% and 65.44% response rates, respectively) were surveyed in 2004.

RESULTS

Seventy-four percent of students in 2000 were not open to future smoking and 77% were not open in 2004. The adolescent cohort in 2004 became more exposed to antitobacco messages and less exposed to protobacco messages and environmental tobacco smoke (ETS) compared with their counterpart in 2000. Whereas gender, grade, race/ethnicity, and exposure to antitobacco messages were insignificant predictors for openness to future smoking, exposure to ETS either in homes or in cars was a strong predictor for openness to future smoking (the higher the exposure to ETS, the more open to future smoking) in both unadjusted and adjusted multivariate models. Exposure to protobacco messages had a greater effect on openness to future smoking than exposure to antitobacco messages. The rate of transition from openness to future smoking to tobacco use initiation is higher among white adolescents than among minority adolescents.

CONCLUSIONS

More efforts should be made to reduce adolescents' exposure to ETS and protobacco messages.

Secondhand tobacco smoke exposure, nicotine dependence, and smoking cessation

OBJECTIVE

To explore the association among the number of sources of secondhand tobacco smoke (SHS) exposure, nicotine dependence (ND), and smoking cessation.

DESIGN

A secondary analysis of cross-sectional data. Responses for the main study were obtained in 2001 from a controlled trial of the Quit and Win Tobacco Free Contest in Kentucky.

SAMPLE

822 current smokers.

MEASUREMENTS

Demographic variables (age, gender, educational status, income, and ethnicity) the number of sources of SHS exposure, smoking frequency, length of abstinence from smoking, age of smoking initiation, smoking cessation attempts, intentions to quit smoking, and ND.

RESULTS

The number of sources of SHS exposure was associated with higher ND and smoking frequency, and related to low intentions and attempts to quit smoking. The number of sources of SHS exposure contributed to 11% of the variance in the final ND model, after accounting for control and potential mediating variables.

CONCLUSIONS

The number of sources of SHS exposure may be an important factor influencing ND and intentions and attempts to quit smoking. Further studies are needed to explore the association between SHS exposure and ND among smokers to guide treatment and policy development.

Does cigarette use influence adiposity or height in adolescence?

PURPOSE

To study the effect of cigarette use on height and adiposity in adolescents.

METHODS

Data on cigarette use were collected every 3 months for 5 years from adolescents initially 12-13 years of age. Height, weight, and triceps skinfold thickness were measured in survey cycles 1, 12, and 19. Multivariate linear regression models were fitted to estimate the association between cigarette use and the anthropometric measures in a dataset that pooled data over two time periods, from survey cycles 1-12 and from survey cycles 12-19.

RESULTS

Data were available for 451 boys and 478 girls. Seven percent of boys and 14% of girls smoked > or =30 cigarettes per month on average during the first time period; 9% of boys and 18% of girls smoked > or =30 cigarettes per month on average during the second time period. In boys, a 100-cigarette per month increment in cigarette use over the preceding 2.5 years was independently associated with lower body mass index (-0.4 kg/m(2)) and shorter height (-0.7 cm). In girls, cigarette use was not associated with height or adiposity.

CONCLUSIONS

While there was no relation in girls, cigarette use appears to decrease body mass index and height in boys. Young girls may be less likely to take up cigarette smoking if tobacco control messages emphasize that cigarette use may not be associated with reduced weight in adolescent females.

Tobacco smoke exposure and tracking of lung function into adult life

Maternal smoking during pregnancy leads to abnormal lung function in infancy that tracks through to later childhood and continues into adult life. This is associated with transient wheezing illnesses through early childhood. Both social and physiological factors are likely to predispose those exposed to passive smoke to become active smokers. Adult smokers demonstrate an increased decline of lung function with age. The effects of passive smoke exposure vary with genetic factors, gender, race and exposure to other pollutants. Exposure to environmental tobacco smoke and subsequent active smoking both aggravate symptoms and have a negative effect on lung function in those with asthma.