Tobacco Smoke Is a Major Source of Aromatic Amine Exposure in U.S. Adults: 2013-2014 National Health and Nutrition Examination Survey (NHANES).

BACKGROUND: Cigarette smoking increases the risk of cancer, cardiovascular diseases, and premature death. Aromatic amines (AA) are found in cigarette smoke and are well-established human bladder carcinogens. METHODS: We measured and compared total urinary levels of 1-aminonaphthalene (1AMN), 2-aminonaphthalene (2AMN), and 4-aminobiphenyl (4ABP) in adults who smoked cigarettes exclusively and in adult nonusers of tobacco products from a nationally representative sample of non-institutionalized U.S. population in the 2013-2014 National Health and Nutrition Examination Survey. RESULTS: Sample-weighted geometric mean concentrations of AAs in adults who smoked cigarettes exclusively compared with adult nonusers were 30 times higher for 1AMN and 4 to 6 times higher for 2AMN and 4ABP. We evaluated the association of tobacco-smoke exposure with urinary AAs using sample-weighted multiple linear regression models to control for age, sex, race/ethnicity, diet, and urinary creatinine. Secondhand smoke exposure status was categorized using serum cotinine (SCOT) among adult nonusers (SCOT ≤ 10 ng/mL). The exposure for adults who smoked cigarettes exclusively (SCOT > 10 ng/mL) was categorized on the basis of the average number of self-reported cigarettes smoked per day (CPD) in the five days prior to urine collection. The regression models show AAs concentration increased with increasing CPD (P < 0.001). Dietary-intake variables derived from the 24-hours recall questionnaire were not consistently significant predictors of urinary AAs. CONCLUSIONS: This is the first characterized total urinary AA concentrations of the U.S. adult non-institutionalized population. Our analyses show that smoking status is a major contributor to AA exposures. IMPACT: These data provide a crucial baseline for exposure to three AAs in U.S. non-institutionalized adults.

E-cigarette and Smokeless Tobacco Use and Switching Among Smokers: Findings From the National Adult Tobacco Survey.

INTRODUCTION: Assessing the extent that cigarette smokers use or switch to e-cigarettes and smokeless tobacco can help inform the population health impact of these products. This study estimated the prevalence of e-cigarette and smokeless tobacco use and switching among current and recent former adult cigarette smokers. METHODS: Data from the 2012-2013 (n=8,891) and 2013-2014 (n=11,379) National Adult Tobacco Survey were analyzed in 2016. Response rates for this telephone survey were 44.9% and 36.1%, respectively. Tobacco product use was assessed by smoking status. RESULTS: Current e-cigarette use increased for all groups, with a greater increase among recent quitters, 9.1% (95% CI=7.1%, 11.1%) in 2012-2013 and 15.8% (95% CI=13.7%, 17.9%) in 2013-2014, than smokers with an unsuccessful quit attempt, 10.4% (95% CI=9.1%, 11.7%) in 2012-2013 and 14.8% (95% CI=13.5%, 16.1%) in 2013-2014, or smokers with no quit attempt, 5.9% (95% CI=4.8%, 6.9%) in 2012-2013 and 10.7% (95% CI=9.4%, 12.0%) in 2013-2014. Between 2012-2013 and 2013-2014, current use of smokeless tobacco remained steady for recent quitters (4.6% to 4.7%, p=0.92) and smokers with no quit attempt (4.0% to 4.3%, p=0.97), and decreased in smokers with an unsuccessful quit attempt (5.7% to 3.8%, p=0.004). More recent quitters completely switched to e-cigarettes in the past year (15.3% in 2012-2013, 25.7% in 2013-2014) than to smokeless tobacco (4.6% in 2012-2013, 4.5% in 2013-2014). CONCLUSIONS: Current and recent former adult smokers are more likely to use e-cigarettes than smokeless tobacco. Current e-cigarette use was most prevalent among unsuccessful quitters and recent quitters, who were substantially more likely to report complete switching to e-cigarettes than smokeless tobacco.

Tobacco Product Use Among Adults - United States, 2015.

Tobacco use remains the leading cause of preventable disease and death in the United States (1). Despite declining cigarette smoking prevalence among U.S. adults, shifts in the tobacco product landscape have occurred in recent years (2,3). Previous estimates of tobacco product use among U.S. adults were obtained from the National Adult Tobacco Survey, which ended after the 2013-2014 cycle. This year, CDC and the Food and Drug Administration (FDA) assessed the most recent national estimates of tobacco product use among adults aged ≥18 years using, for the first time, data from the 2015 National Health Interview Survey (NHIS), an annual, nationally representative, in-person survey of the noninstitutionalized U.S. civilian population. The 2015 NHIS adult core questionnaire included 33,672 adults aged ≥18 years, reflecting a 55.2% response rate. Data were weighted to adjust for differences in selection probability and nonresponse, and to provide nationally representative estimates. In 2015, 20.1 % of U.S. adults currently (every day or some days) used any tobacco product, 17.6% used any combustible tobacco product, and 3.9% used ≥2 tobacco products. By product, 15.1% of adults used cigarettes; 3.5% used electronic cigarettes (e-cigarettes); 3.4% used cigars, cigarillos, or filtered little cigars; 2.3% used smokeless tobacco; and 1.2% used regular pipes, water pipes, or hookahs.* Current use of any tobacco product was higher among males; persons aged <65 years; non-Hispanic American Indian/Alaska natives (AI/AN), whites, blacks, and persons of multiple races; persons living in the Midwest; persons with a General Educational Development (GED) certificate; persons with annual household income of <$35,000; persons who were single, never married, or not living with a partner or divorced, separated, or widowed; persons who were insured through Medicaid or uninsured; persons with a disability; and persons who identified as lesbian, gay, or bisexual (LGB). Current use of any tobacco product was 47.2% among adults with serious psychological distress compared with 19.2% among those without serious psychological distress. Proven population-level interventions that focus on the diversity of tobacco product use are important to reducing tobacco-related disease and death in the United States (1).

Tobacco Use Among Middle and High School Students - United States, 2011-2016.

Tobacco use is the leading cause of preventable disease and death in the United States; nearly all tobacco use begins during youth and young adulthood (1,2). Among youths, use of tobacco products in any form is unsafe (1,3). CDC and the Food and Drug Administration (FDA) analyzed data from the 2011-2016 National Youth Tobacco Surveys (NYTS) to determine recent patterns of current (past 30-day) use of seven tobacco product types among U.S. middle (grades 6-8) and high (grades 9-12) school students. In 2016, 20.2% of surveyed high school students and 7.2% of middle school students reported current tobacco product use. In 2016, among current tobacco product users, 47.2% of high school students and 42.4% of middle school students used ≥2 tobacco products, and electronic cigarettes (e-cigarettes) were the most commonly used tobacco product among high (11.3%) and middle (4.3%) school students. Current use of any tobacco product did not change significantly during 2011-2016 among high or middle school students, although combustible tobacco product use declined. However, during 2015-2016, among high school students, decreases were observed in current use of any tobacco product, any combustible product, ≥2 tobacco products, e-cigarettes, and hookahs. Among middle school students, current use of e-cigarettes decreased. Comprehensive and sustained strategies can help prevent and reduce the use of all forms of tobacco products among U.S. youths (1-3).

Flavoured non-cigarette tobacco product use among US adults: 2013-2014.

INTRODUCTION: Limited data exist on flavoured non-cigarette tobacco product (NCTP) use among US adults. METHODS: Data from the 2013 to 2014 National Adult Tobacco Survey (N=75 233), a landline and cellular telephone survey of US adults aged ≥18, were assessed to estimate past 30-day NCTP use, flavoured NCTP use and flavour types using bivariate analyses. RESULTS: During 2013-2014, 14.4% of US adults were past 30-day NCTP users. Nationally, an estimated 10.2 million e-cigarette users (68.2%), 6.1 million hookah users (82.3%), 4.1 million cigar smokers (36.2%) and 4.0 million smokeless tobacco users (50.6%) used flavoured products in the past 30 days. The most prevalent flavours reported were menthol/mint (76.9%) for smokeless tobacco; fruit (74.0%) for hookah; fruit (52.4%), candy/chocolate/other sweet flavours (22.0%) and alcohol (14.5%) for cigars/cigarillos/filtered little cigars; fruit (44.9%), menthol/mint (43.9%) and candy/chocolate/other sweet flavours (25.7%) for e-cigarettes and fruit (56.6%), candy/chocolate/other sweet flavours (26.5%) and menthol/mint (24.8%) for pipes. Except for hookah and pipes, past 30-day flavoured product use was highest among 18-24-year olds. By cigarette smoking, never smoking e-cigarette users (84.8%) were more likely to report flavoured e-cigarette use, followed by recent former smokers (78.1%), long-term former smokers (70.4%) and current smokers (63.2%). CONCLUSIONS: Flavoured NCTP use is prominent among US adult tobacco users, particularly among e-cigarette, hookah and cigar users. Flavoured product use, especially fruit and sweet-flavoured products, was higher among younger adults. It is important for tobacco prevention and control strategies to address all forms of tobacco use, including flavoured tobacco products.

Flavored Tobacco Product Use Among Middle and High School Students--United States, 2014.

The 2009 Family Smoking Prevention and Tobacco Control Act prohibits "characterizing flavors" (e.g., candy, fruit, and chocolate) other than tobacco and menthol in cigarettes; however, characterizing flavors are not currently prohibited in other tobacco products. Analyses of retail sales data suggest that U.S. consumption of flavored noncigarette tobacco products, including flavored cigars and flavored e-cigarettes, has increased in recent years. There is growing concern that widely marketed varieties of new and existing flavored tobacco products might appeal to youths (2) and could be contributing to recent increases in the use of tobacco products, including e-cigarettes and hookah, among youths. CDC and the Food and Drug Administration (FDA) analyzed data from the 2014 National Youth Tobacco Survey (NYTS) to determine the prevalence of past 30 day use (current use) of flavored e-cigarette, hookah tobacco, cigar, pipe tobacco or smokeless tobacco products, and menthol cigarettes among middle and high school students, and the proportion of current tobacco product users who have used flavored products. An estimated 70.0% (3.26 million) of all current youth tobacco users had used at least one flavored tobacco product in the past 30 days. Among current users, 63.3%, (1.58 million) had used a flavored e-cigarette, 60.6%, (1.02 million) had used flavored hookah tobacco, and 63.5% (910,000) had used a flavored cigar in the past 30 days. Given the millions of current youth tobacco users, it is important for comprehensive tobacco prevention and control strategies to address all forms of tobacco use, including flavored tobacco products, among U.S. youths.

Systematic review of cigar smoking and all cause and smoking related mortality.

BACKGROUND: Cigars are a growing public health concern, given the changes in cigar use patterns in the US and elsewhere since the 1960s. We conducted a systematic review of published studies on current cigar smoking and all-cause and cause-specific mortality risks to inform potential regulatory approaches and future research that would strengthen the body of evidence. METHODS: Using 3 different databases and handsearching, we identified epidemiological studies published prior to June 2014 that examined the association between cigar smoking and all-cause mortality and smoking-related mortality. Detailed study characteristics as well as association-level characteristics, including effect estimates and 95% confidence intervals, were abstracted or calculated from each selected study. RESULTS: A total of 22 studies from 16 different prospective cohorts were identified. Primary cigar smoking (current, exclusive cigar smoking with no history of previous cigarette or pipe smoking) was associated with all cause-mortality, oral cancer, esophageal cancer, pancreatic cancer, laryngeal cancer, lung cancer, coronary heart disease (CHD), and aortic aneurysm. Strong dose trends by cigars per day and inhalation level for primary cigar smoking were observed for oral, esophageal, laryngeal, and lung cancers. Among primary cigar smokers reporting no inhalation, relative mortality risk was still highly elevated for oral, esophageal, and laryngeal cancers. CONCLUSIONS: In summary, cigar smoking carries many of the same health risks as cigarette smoking. Mortality risks from cigar smoking vary by level of exposure as measured by cigars per day and inhalation level and can be as high as or exceed those of cigarette smoking. The body of evidence would be strengthened by future studies that focus on the health effects of primary cigar smoking and incorporate more contemporary and diverse study populations to better reflect the current patterns of cigar use in the US. Ideally, these studies would also collect detailed information on cigar type, exposure level, and biomarkers of exposure and potential harm.

A systematic review of transitions between cigarette and smokeless tobacco product use in the United States.

BACKGROUND: Smokeless tobacco use is becoming an increasingly important public health issue in the US and may influence cigarette smoking behavior. Systematic information on transitions between smokeless tobacco and cigarette use in the US is limited. METHODS: We conducted a systematic review of published literature on transitions between smokeless tobacco and cigarette use in the US. We searched PubMed, Web of Science and EbscoHost databases for all published articles from January 2000 to March 2014 that presented estimates of transitions in US youth and adult study populations over time between at least one of the following tobacco use states: exclusive cigarette smoking, exclusive smokeless tobacco use, dual use of both products, and use of neither product. We excluded non-English language studies, studies published before 2000, clinical trials, controlled cessation programs, and clinical studies or evaluations of smokeless tobacco cessation programs. RESULTS: The review identified six studies on US populations published since 2000 with longitudinal data on some or all of the transitions that users can undergo between smokeless tobacco and cigarette use. There was considerable heterogeneity across studies in design and tobacco use definitions. Despite these differences, the existing data indicate that switching behaviors from exclusive smoking to exclusive smokeless tobacco use are limited (adults: 0%-1.4%, adolescents: 0.8%-3.8%) but may be more common from exclusive smokeless tobacco use to exclusive smoking (adults: 0.9%-26.6%, adolescents: 16.6%-25.5%). Among adults, exclusive cigarette smoking was generally stable and consistent (79.7% to 87.6%) over follow-up across studies but less stable in adolescents (46.8%-78.7%). Exclusive smokeless tobacco use was less stable than exclusive cigarette smoking over time (adults: 59.4%-76.6%, adolescents: 26.2%-44.8%). CONCLUSION: This review provides published estimates of the proportions of adults and adolescents transitioning between tobacco use categories from the most recently available studies on longitudinal transitions between smokeless tobacco and cigarettes in the US. These data can be used to track tobacco use behaviors and evaluate their effect on public health; however, the data for these studies were generally collected more than a decade ago. Additional research including nationally representative longitudinal estimates using consistent definitions and designs, would improve understanding of current tobacco transition behaviors.

Tobacco use among middle and high school students - United States, 2011-2014.

Tobacco use and addiction most often begin during youth and young adulthood. Youth use of tobacco in any form is unsafe. To determine the prevalence and trends of current (past 30-day) use of nine tobacco products (cigarettes, cigars, smokeless tobacco, e-cigarettes, hookahs, tobacco pipes, snus, dissolvable tobacco, and bidis) among U.S. middle (grades 6-8) and high school (grades 9-12) students, CDC and the Food and Drug Administration (FDA) analyzed data from the 2011-2014 National Youth Tobacco Surveys (NYTS). In 2014, e-cigarettes were the most commonly used tobacco product among middle (3.9%) and high (13.4%) school students. Between 2011 and 2014, statistically significant increases were observed among these students for current use of both e-cigarettes and hookahs (p<0.05), while decreases were observed for current use of more traditional products, such as cigarettes and cigars, resulting in no change in overall tobacco use. Consequently, 4.6 million middle and high school students continue to be exposed to harmful tobacco product constituents, including nicotine. Nicotine exposure during adolescence, a critical window for brain development, might have lasting adverse consequences for brain development, causes addiction, and might lead to sustained tobacco use. For this reason, comprehensive and sustained strategies are needed to prevent and reduce the use of all tobacco products among youths in the United States.

Modeling the potential effects of new tobacco products and policies: a dynamic population model for multiple product use and harm.

BACKGROUND: Recent declines in US cigarette smoking prevalence have coincided with increases in use of other tobacco products. Multiple product tobacco models can help assess the population health impacts associated with use of a wide range of tobacco products. METHODS AND FINDINGS: We present a multi-state, dynamical systems population structure model that can be used to assess the effects of tobacco product use behaviors on population health. The model incorporates transition behaviors, such as initiation, cessation, switching, and dual use, related to the use of multiple products. The model tracks product use prevalence and mortality attributable to tobacco use for the overall population and by sex and age group. The model can also be used to estimate differences in these outcomes between scenarios by varying input parameter values. We demonstrate model capabilities by projecting future cigarette smoking prevalence and smoking-attributable mortality and then simulating the effects of introduction of a hypothetical new lower-risk tobacco product under a variety of assumptions about product use. Sensitivity analyses were conducted to examine the range of population impacts that could occur due to differences in input values for product use and risk. We demonstrate that potential benefits from cigarette smokers switching to the lower-risk product can be offset over time through increased initiation of this product. Model results show that population health benefits are particularly sensitive to product risks and initiation, switching, and dual use behaviors. CONCLUSION: Our model incorporates the variety of tobacco use behaviors and risks that occur with multiple products. As such, it can evaluate the population health impacts associated with the introduction of new tobacco products or policies that may result in product switching or dual use. Further model development will include refinement of data inputs for non-cigarette tobacco products and inclusion of health outcomes such as morbidity and disability.

Intentions to smoke cigarettes among never-smoking US middle and high school electronic cigarette users: National Youth Tobacco Survey, 2011-2013.

INTRODUCTION: Electronic cigarette (e-cigarette) use is increasing rapidly, and the impact on youth is unknown. We assessed associations between e-cigarette use and smoking intentions among US youth who had never smoked conventional cigarettes. METHODS: We analyzed data from the nationally representative 2011, 2012, and 2013 National Youth Tobacco Surveys of students in grades 6-12. Youth reporting they would definitely not smoke in the next year or if offered a cigarette by a friend were defined as not having an intention to smoke; all others were classified as having positive intention to smoke conventional cigarettes. Demographics, pro-tobacco advertisement exposure, ever use of e-cigarettes, and ever use of other combustibles (cigars, hookah, bidis, kreteks, and pipes) and noncombustibles (chewing tobacco, snuff, dip, snus, and dissolvables) were included in multivariate analyses that assessed associations with smoking intentions among never-cigarette-smoking youth. RESULTS: Between 2011 and 2013, the number of never-smoking youth who used e-cigarettes increased 3-fold, from 79,000 to more than 263,000. Intention to smoke conventional cigarettes was 43.9% among ever e-cigarette users and 21.5% among never users. Ever e-cigarette users had higher adjusted odds for having smoking intentions than never users (adjusted odds ratio = 1.70, 95% confidence interval = 1.24-2.32). Those who ever used other combustibles, ever used noncombustibles, or reported pro-tobacco advertisement exposure also had increased odds for smoking intentions. CONCLUSION: In 2013, more than a quarter million never-smoking youth used e-cigarettes. E-cigarette use is associated with increased intentions to smoke cigarettes, and enhanced prevention efforts for youth are important for all forms of tobacco, including e-cigarettes.

Association between electronic cigarette use and openness to cigarette smoking among US young adults.

INTRODUCTION: Use of electronic nicotine delivery systems (ENDS), including electronic cigarettes (e-cigarettes), is increasing. One concern is the appeal of these products to youth and young adults and the potential to influence perceptions and use of conventional cigarettes. METHODS: Using data from the 2012-2013 National Adult Tobacco Survey, characteristics of adults aged 18-29 years who had never established cigarette smoking behavior were examined by ever use of e-cigarettes, demographics, and ever use of other tobacco products (smokeless tobacco, cigars, hookah, and cigarettes). Multivariate logistic regression was used to examine the relationship between e-cigarette use and openness to cigarette smoking among young adults, defined as the lack of a firm intention not to smoke soon or in the next year. RESULTS: Among young adults who had never established cigarette smoking behavior (unweighted n = 4,310), 7.9% reported having ever tried e-cigarettes, and 14.6% of those who reported having ever tried e-cigarettes also reported current use of the product. Ever e-cigarette use was associated with being open to cigarette smoking (adjusted odds ratio = 2.4; 95% confidence interval = 1.7, 3.3), as was being male, aged 18-24 years, less educated, and having ever used hookah or experimented with conventional cigarettes. CONCLUSIONS: Ever use of e-cigarettes and other tobacco products was associated with being open to cigarette smoking. This study does not allow us to assess the directionality of this association, so future longitudinal research is needed to illuminate tobacco use behaviors over time as well as provide additional insight on the relationship between ENDS use and conventional cigarette use among young adult populations.

Little filtered cigar, cigarillo, and premium cigar smoking among adults--United States, 2012-2013.

The burden of death and disease from tobacco use in the United States has been caused overwhelmingly by cigarettes and other smoked tobacco products. In the United States, cigarette consumption declined during 2000-2011; however, consumption of cigars more than doubled during the same period. The cigar market includes diverse product types manufactured with a variety of shapes and sizes, filters, tips, flavors, and prices. Although national estimates of cigar consumption have been reported previously, data characterizing who smokes different cigar types are limited. A recent analysis from the 2012-2013 National Adult Tobacco Survey (NATS) found that more than one in 20 U.S. adults smoke cigars "every day," "someday," or "rarely". This report expands upon those findings, using data from the 2012-2013 NATS to further characterize cigar smokers by the usual type of cigar smoked using the following categories: little filtered cigars (LFCs), cigarillos/other mass market cigars (cigarillos/MMCs), and premium cigars. The findings indicate that among U.S. adults who smoke cigars, 61.8% usually smoke cigarillos/MMCs, 19.9% usually smoke premium cigars, and the remainder, 18.4%, usually smoke LFCs. These data can help to inform public health interventions to reduce the burden of adverse health effects caused by cigar smoking in the United States, including regulation.

Utility and cutoff value of hair nicotine as a biomarker of long-term tobacco smoke exposure, compared to salivary cotinine.

While hair samples are easier to collect and less expensive to store and transport than biological fluids, and hair nicotine characterizes tobacco exposure over a longer time period than blood or urine cotinine, information on its utility, compared with salivary cotinine, is still limited. We conducted a cross-sectional study with 289 participants (107 active smokers, 105 passive smokers with self-reported secondhand smoke (SHS) exposure, and 77 non-smokers with no SHS exposure) in Baltimore (Maryland, USA). A subset of the study participants (n = 52) were followed longitudinally over a two-month interval.  Median baseline hair nicotine concentrations for active, passive and non-smokers were 16.2, 0.36, and 0.23 ng/mg, respectively, while those for salivary cotinine were 181.0, 0.27, and 0.27 ng/mL, respectively. Hair nicotine concentrations for 10% of passive or non-smokers were higher than the 25th percentile value for active smokers while all corresponding salivary cotinine concentrations for them were lower than the value for active smokers. This study showed that hair nicotine concentration values could be used to distinguish active or heavy passive adult smokers from non-SHS exposed non-smokers. Our results indicate that hair nicotine is a useful biomarker for the assessment of long-term exposure to tobacco smoke.

Cigar smoking among U.S. students: reported use after adding brands to survey items.

BACKGROUND: Among U.S. youth overall, cigars are the most commonly used tobacco product after cigarettes. However, youth who identify their products by brand names, not general terms like "cigar," may underreport use. PURPOSE: To examine changes in reported cigar (cigar, cigarillo, or little cigar) smoking among students following inclusion of cigar brand examples on the National Youth Tobacco Survey (NYTS). METHODS: Data from the 2011 and 2012 NYTS and National Survey on Drug Use and Health (NSDUH) were analyzed in 2013 to estimate ever and current cigar smoking, overall and by race/ethnicity. The 2012 NYTS included cigar brand examples (Black and Mild, Swisher Sweets, Dutch Masters, White Owl, Phillies Blunt) in the survey instructions and ever use question, but the 2011 NYTS and 2011 and 2012 NSDUH did not. RESULTS: NYTS ever cigar smoking was higher in 2012 (27.8%) than 2011 (19.5%) among black students overall. Current cigar smoking was 60%-70% higher among black females and students aged ≥ 17 years, in 2012 than 2011. For black females, current cigar smoking (11.5%) was two times greater than that of white females (4.3%) in 2012, whereas the prevalence among these subgroups was comparable in 2011. Similar changes were not observed among these subgroups in the 2011-2012 NSDUH. CONCLUSIONS: This study highlights the high burden of cigar use among U.S. youth and suggests that NYTS ascertainment of cigar smoking may have improved by including brands. Disparities in cigar smoking need to be addressed to prevent and reduce all youth tobacco use.

Symptoms of tobacco dependence among middle and high school tobacco users: results from the 2012 National Youth Tobacco Survey.

BACKGROUND: A growing body of evidence suggests that tobacco dependence symptoms can occur soon after smoking onset and with low levels of use. However, limited data are available nationally and among non-cigarette tobacco users. PURPOSE: To examine the prevalence and determinants of tobacco dependence symptoms among adolescent tobacco users in the 2012 National Youth Tobacco Survey, a nationally representative, school-based survey of U.S. middle and high school students. METHODS: Multivariate logistic regression was used to identify independent predictors of dependence symptoms among current users (i.e., past 30-day use) of cigarettes, cigars, or smokeless tobacco. Analyses were conducted in 2013 using SAS-callable SUDAAN, version 11 to account for the complex survey design. RESULTS: Prevalence of tobacco dependence symptoms ranged from 20.8% (95% CI=18.6, 23.1) of current tobacco users reporting wanting to use tobacco within 30 minutes of waking to 41.9% (95% CI=39.3, 44.5) reporting recent strong cravings. Reporting of dependence symptoms was most consistently associated with polytobacco use, higher frequency of use, earlier initiation age, and female gender. A 2-4-fold increase in the odds of symptom reporting was found in adolescents using tobacco products on as few as 3-5 days compared to those who only used it for 1-2 of the past 30 days. CONCLUSIONS: A substantial proportion of U.S. adolescent tobacco users, including those with low levels of use, report symptoms of tobacco dependence. These findings demonstrate the need for full implementation of evidence-based strategies to prevent both experimentation and progression to regular tobacco use among youth.

Perceptions of the relative harm of cigarettes and e-cigarettes among U.S. youth.

BACKGROUND: Despite progress in reducing youth smoking, adolescents remain highly susceptible to tobacco use. Of concern is whether youth perceive electronic cigarettes (e-cigarettes) as a preferable alternative to conventional cigarettes. PURPOSE: To describe cigarette harm perception patterns among youth based on the frequency and intensity of cigarette smoking, and examine the relative harm perceptions of conventional versus e-cigarettes, using data from a large, nationally representative sample of U.S. youth. METHODS: Data from the 2012 National Youth Tobacco Survey (N=24,658) were analyzed in 2013 to identify patterns of cigarette harm perceptions. Multinomial logistic regression was conducted to identify associations between demographic and tobacco use characteristics and cigarette harm perception patterns. Logistic regression was conducted to examine the relationship between cigarette harm perceptions and the perception of e-cigarettes as less harmful than cigarettes for current, ever, and never cigarette smokers. RESULTS: The majority of youth (64.2%) perceived the harmfulness of cigarettes as dose-dependent. Approximately one in three students perceived e-cigarettes as less harmful than conventional cigarettes. Regardless of cigarette smoking status, ever users of e-cigarettes and those with "dose-dependent" cigarette harm perceptions consistently were more likely to perceive e-cigarettes as less harmful than conventional cigarettes. CONCLUSIONS: Many youth perceive tobacco use on a continuum of harm. Youth who perceive gradations in harm-both by frequency and intensity of cigarette use and by type of product-may be particularly susceptible to e-cigarette use.