Transitions between smoking and vaping: Evidence (or lack thereof) on potential differences by gender and sex.

OBJECTIVE: To synthesize existing evidence on possible differential effects by sex and gender from two Cochrane reviews evaluating vaping and smoking transitions. METHODS: We screened included studies from two Cochrane reviews for studies reporting smoking outcomes based on gender or sex. The first review examines the effects of using e-cigarettes to help people quit smoking and includes randomized controlled trials and uncontrolled intervention studies published to July 2023. The second review aims to assess the evidence on the relationship between the use and availability of e-cigarettes and subsequent smoking in young people (aged 29 and younger) and includes quasi-experimental and cohort studies published to April 2023. Due to the paucity and heterogeneity of data, we report results narratively. RESULTS: 10 of 161 studies included in the two relevant reviews met our criteria. Only five reported analyzing whether observed effects or associations varied based on sex and/or gender. A further three provided relevant descriptive information, and two did not report overall outcomes regarding vaping and smoking transitions but did investigate whether these differed by sex/gender. Synthesized data were largely inconclusive, but there was some suggestion that vaping was more strongly associated with subsequent smoking in young males than females. No studies reported data on nonbinary participants. CONCLUSIONS: Despite plausible reasons why sex and gender may be moderators of vaping and smoking transitions, there is little evidence investigating this. Future studies of vaping and smoking transitions should conduct and report analyses investigating potential differences based on sex and gender.

Smoking may increase the usage of antidepressant: evidence from genomic perspective analysis.

This study uses the two-sample Mendelian randomization (TSMR) method to explore the causal relationships between smoking initiation (SMKI), never smoking (NSMK), past tobacco smoking (PTSMK), and the usage of antidepressants (ATD). Single-nucleotide polymorphisms (SNPs) with genome-wide significance (P < 5E-08) related to SMKI, NSMK, and PTSMK were selected from the genome-wide association study (GWAS) database as instrumental variables (IVs). The main method, inverse variance weighted (IVW), was utilized to investigate the causal relationship. The results demonstrated a positive causal relationship between SMKI and ATD use, where SMKI leads to an increase in ATD use. Conversely, NSMK and PTSMK showed a negative causal relationship with ATD use, meaning that NSMK and PTSMK lead to a reduction in ATD use. Additionally, sensitivity analysis showed that the results of this study were robust and reliable. Using the TSMR method and from a genetic perspective, this study found that SMKI leads to an increase in ATD use, while NSMK and PTSMK reduce ATD use.

Association Between Temporary Employment and Current Smoking and Change in Smoking Behaviors: A Prospective Cohort Study From South Korea (2009-2018).

BACKGROUND: Previous studies have suggested that employment insecurity is associated with adverse health outcomes. We explored the association between temporary employment and smoking behaviors. METHODS: We analyzed 11,795 workers (51,867 observations) from the Korea Health Panel Study (2009-2018). Employment types were categorized as regular, fixed-term, or daily, based on the duration of labor contract. The outcomes were current smoking status and changes in smoking behavior (initiation or cessation) in the following year. Generalized estimating equations were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: The proportions of fixed-term and daily workers were 41.2% and 16.4% for women and 23.6% and 12.4% for men, respectively. Temporary employment was associated with increased odds of current smoking, while also demonstrating prospective associations with changes in smoking behaviors. For instance, in prospective analyses, male workers with fixed-term and daily employments were associated with a decreased likelihood of smoking cessation (OR 0.77; 95% CI, 0.65-0.91 for fixed-term employment and OR 0.66; 95% CI, 0.52-0.83 for daily employment) in the following year compared to those with regular employment. Moreover, those experiencing consecutive temporary employment was most inversely associated with smoking cessation in both men (OR 0.56; 95% CI, 0.44-0.71) and women (OR 0.37; 95% CI, 0.16-0.85) compared to those experiencing consecutive regular employment. However, no clear association between temporary employment and smoking initiation was observed in both men and women. CONCLUSION: Temporary employment is directly associated with current smoking and inversely associated with smoking cessation. Policies are needed to improve job insecurity among temporary employees.

A systematic review and meta-analysis of the association between e-cigarette use among non-tobacco users and initiating smoking of combustible cigarettes.

INTRODUCTION: The rapid increase in e-cigarette use over the past decade has triggered an important public health question on the potential association between e-cigarette use and combustible cigarette smoking. Following AMSTAR 2 and PRISMA guidelines, this evidence synthesis sought to identify and characterize any associations between e-cigarette use among individuals not smoking cigarettes and initiation of cigarette smoking. METHODS: The protocol was registered on September 24, 2018 (PROSPERO 2018 CRD42018108540). Three databases were queried from January 01, 2007 to April 26, 2023. Search results were screened using the PICOS review method. RESULTS: Among 55 included studies (40 "good" and 15 "fair"; evidence grade: "high") that adjusted for gender, age, and race/ethnicity between groups, generally, there was a significant association between non-regular e-cigarette use and initiation of cigarette smoking, further supported by the meta-analytic results (AOR 3.71; 95% CI 2.86-4.81). However, smoking initiation was most often measured as ever/current cigarette smoking. Two studies (quality: 2 "good") evaluated progression to regular cigarette smoking among individuals with regular use of e-cigarettes, and generally found no significant associations. One study ("good") evaluated smoking initiation among individuals with regular use of e-cigarettes, finding an increasing probability of ever smoking cigarettes with increased e-cigarette use. Twelve studies (10 "good" and two "fair") examining progression to regular smoking among individuals with non-regular use of e-cigarettes reported inconsistent findings. CONCLUSIONS: Numerous methodological flaws in the body of literature limit the generalizability of these results to all individuals who are not smoking cigarettes with few studies measuring established/regular use/smoking of e-cigarettes and cigarettes. Further, studies did not control adequately for specific confounding variables representing common liabilities between e-cigarette use and cigarette smoking, nor did they account for sufficient follow-up durations. Collectively, these flaws limit the generalizability of findings to the question of an association between e-cigarette use and cigarette smoking initiation.

Age of Smoking Initiation in Relation to Multiple Health Risk Factors among US Adult Smokers: National Health Interview Survey (NHIS) Data (2006-2018).

The adverse effects of multiple health risk factors have been well-documented; however, still understudied are the effects of early smoking in the context of multiple health risk factors. This study aimed to examine the role of early smoking initiation in relation to several health risk factors, including heavy drinking, physical inactivity, and obesity in later life among ever smokers in the USA. The National Health Interview Survey (NHIS) data from 2006 through 2018 were analyzed. The primary dependent variables were presence of three other risk factors: heavy drinking, physical inactivity, and obesity. The independent variable was the age of smoking initiation. Logit regression models were constructed to evaluate the association between smoking initiation and multiple health risk factors. All analyses were done in 2022. Among US adult smokers, 18.2% started smoking before age 15 (early initiators), 55.9% at ages 15-18 (middle initiators), and 25.9% at age 20 or later (late initiators). Compared to late smoking initiators, the odds of engaging in additional health risk factors increased by 37.3% among early initiators (OR = 1.373, 95% CI = 1.316, 1.432) and 7.7% among middle initiators (OR = 1.077, 95% CI= 1.041, 1.116). Additionally, current smoking was associated with higher odds (OR = 1.369, 95% CI = 1.322, 1.417) of having additional health risk factors compared to former smoking, with one exception: current smokers had lower odds of obesity (OR = 0.566, 95% CI = 0.537, 0.597). Tobacco control programs to prevent adolescents from initiating smoking may have the potential to prevent other health risk factors in adulthood.

Sex and macroeconomic differences and trends in early attempts at cigarette smoking among adolescents: findings from 147 countries.

BACKGROUND: Most tobacco users initiate smoking during adolescence. Little is known about the global prevalence and trends in early cigarette smoking among adolescents. This study aimed to evaluate the prevalence of early attempts at cigarette smoking and its change trends among young adolescents. METHODS: We used data from the Global Youth Tobacco Surveys on adolescents aged 12-16 years, comprising 456,634 participants from 147 countries between 2006 and 2018, to estimate the prevalence of early attempts at cigarette smoking and age distribution at attempt by sex, country income, purchasing power parity (PPP) per capita, and WHO region. We assessed the average annual rate of reduction (AARR) in the prevalence of attempts at cigarette smoking before 12 years of age in 70 countries that had data from three or more surveys completed between 1999 and 2018. RESULTS: The average prevalence of early attempts at cigarette smoking was 12.2% (95% CI: 10.9-13.5) for boys and 6.7% (95% CI: 5.8-7.6) for girls, with the highest prevalence of 17.4% for boys and 10.7% for girls in the European region. Along with the growth of the national economy, the prevalence of early attempts at cigarette smoking gradually increased in both sexes. A total of 22.9% and 30% of countries had a negative change in AARR for boys and for girls, respectively. The countries with an upward prevalence were mainly located in the Eastern Mediterranean, Southeast Asia, and African regions. The age distribution at first cigarette smoked did not differ substantially between sexes. Notably, the age at first cigarette smoked of 10.7 years for girls was significantly earlier than that of 11.8 years for boys in low-income countries. Among cigarette-smoking adolescents, the average percentage of girls reporting smoking their first cigarette at an age <12 years was 55.7% in Q1 for PPP quintiles, 46.5% in Q2, 40.3% in Q3, 38.4% in Q4, and 34.6% in Q5, and the corresponding prevalence for boys was 46.0% in Q1, 42.8% in Q2, 42.9% in Q3, 43.5% in Q4, and 41.1% in Q5. CONCLUSIONS: The global prevalence of early attempts at cigarette smoking among adolescents was substantial, with differences by sex and macroeconomic situation, and our findings stress that interventions and policies targeting the first smoking experience are required to prevent the initiation of tobacco use among early adolescents, especially girls in low-income countries.

Propensity score stratification methods for continuous treatments.

Continuous treatments propensity scoring remains understudied as the majority of methods are focused on the binary treatment setting. Current propensity score methods for continuous treatments typically rely on weighting in order to produce causal estimates. It has been shown that in some continuous treatment settings, weighting methods can result in worse covariate balance than had no adjustments been made to the data. Furthermore, weighting is not always stable, and resultant estimates may be unreliable due to extreme weights. These issues motivate the current development of novel propensity score stratification techniques to be used with continuous treatments. Specifically, the generalized propensity score cumulative distribution function (GPS-CDF) and the nonparametric GPS-CDF approaches are introduced. Empirical CDFs are used to stratify subjects based on pretreatment confounders in order to produce causal estimates. A detailed simulation study shows superiority of these new stratification methods based on the empirical CDF, when compared with standard weighting techniques. The proposed methods are applied to the "Mexican-American Tobacco use in Children" study to determine the causal relationship between continuous exposure to smoking imagery in movies, and smoking behavior among Mexican-American adolescents. These promising results provide investigators with new options for implementing continuous treatment propensity scoring.

The past is not the future in tobacco control.

In this paper we have attempted to identify missed opportunities to change the trajectory of smoking and smoking caused diseases in America over the past 100 years. Many of the missed opportunities identified are due to the actions of cigarette manufacturers who misled the public about the dangers of cigarette smoking, the addictiveness of nicotine, and the feasibility of providing lower risk alternative nicotine delivery products to addicted smokers. An important lesson learned from the past is that treating all tobacco/nicotine products as equivalently harmful is counterproductive to public health as it only serves to protect the most lethal nicotine product - cigarettes. Since 2000, the evolving marketplace of lower risk nicotine products combined with regulatory authority over tobacco products represents a new opportunity to dramatically transform the cigarette business in ways that were never imagined when the war on tobacco was raging decades ago. However, this requires embracing risk-proportionate regulation, taxation policies, and providing consumers with accurate public messaging on product relative risks. A regulatory framework based on sound science that encourages and rewards new or existing manufacturers to invest in consumer acceptable lower risk products to replace cigarettes needs to be encouraged. The past is indeed not the future in smoking control, but it may be difficult to escape the past unless a realignment of market forces and policies can be achieved.

Association of snus experimentation in late adolescence with daily cigarette smoking in early adulthood: A longitudinal study among Finnish men.

Aims: Swedish smokeless tobacco (snus) is a lower-risk tobacco product than cigarette smoking for individuals. However, the public health impact of snus use is less well studied. Critically, it is uncertain whether use of snus leads to the onset of smoking. This study aimed to investigate prospectively the association between snus experimentation in late adolescence and daily cigarette smoking in early adulthood among Finnish young men. Methods: Data were obtained from 1090 young men within the population-based FinnTwin12 cohort. At baseline (mean age 17 years), we assessed lifetime use of cigarettes and snus, plus other potential predictors of cigarette smoking. At follow-up (mean age 24 years), participants were categorized according to their current smoking status. The final analyses were conducted among 375 young men who were never smokers at baseline with adequate data on follow-up smoking status and other potential predictors of cigarette smoking. Results: Age-adjusted logistic regressions showed an increased risk of becoming a daily smoker at follow-up among those participants who had at least tried snus but had never smoked cigarettes at baseline (odds ratio (OR) 6.48, 95% confidence interval (CI) 2.02-20.7), compared with those who had never used snus. When additionally adjusted for monthly alcohol intoxication, maternal smoking, and peer drug use, the association between snus experimentation and later daily cigarette smoking was attenuated, but remained significant (OR 3.94, 95% CI 1.22-12.7). Conclusions: Our data support the proposition that snus experimentation during late adolescence is longitudinally associated with daily cigarette smoking in early adulthood. Although a causal association cannot be inferred with certainty, snus experimentation might constitute an indicator of the propensity to proceed to regular snus use and initiation of use of other tobacco or nicotine products.

The First Cigarette Smoking Experience and Future Smoking Behaviors Among Adolescents with Different Parental Risk: a Longitudinal Analysis in an Urban Iranian Population.

BACKGROUND: Longitudinal research among Iranian adolescent smoking is limited. The current study aimed to investigate (1) the first smoking experience (FSE) and future smoking behaviors of adolescents with different parental risk factors and (2) the association between age of the FSE and future smoking behaviors over a 12-year follow-up. METHOD: Based on Tehran Lipid and Glucose Study (TLGS) database, 1487 adolescents (12-18 years) with complete baseline parental data were recruited. Using two-step cluster analysis, families were classified as either high or low risk; these were based on parental risk factors including age, education, employment, and smoking status. Participants were examined four times in 12 years and their data were used for survival analysis. After exclusion of 24 cases who were smokers at baseline, Cox proportional hazard modeling was used to evaluate the effect of parental clusters on the FSE in 1463 nonsmoking adolescents who completed all prospective follow-ups. Logistic regression analysis was used to examine the effect of the age of FSE on future smoking behaviors. RESULTS: The mean age of adolescents was 14.63 ± 2.07 years at baseline. Adolescents in the high-risk cluster group were 49% more likely to try smoking for their first time, and 55% more likely to smoke in the future. Compared with girls, boys had 83% higher chance of trying their first cigarette. Moreover, 1-year delay in the FSE resulted in 25% reduction in the probability of smoking in the future. CONCLUSION: The findings show that compared with adolescents living in low-risk families, teenagers living in high-risk families are at greater risk of smoking at an earlier age; therefore, this group could benefit from gender- and culture specific preventive interventions.

Trends in age of smoking initiation among the Chinese population born between 1950 and 1997.

OBJECTIVES: Smoking prevalence has significantly increased among Chinese adolescences in the past decades. The aim of our study is to investigate the trends and changing patterns in age of smoking initiation among the Chinese population. STUDY DESIGN: Pooled data from the 2006-2015 China Health and Nutrition Survey was used for analysis. A total of 10,032 adults aged ≥18 years who were born between 1950 and 1997 were separated into five birth cohorts (1950-1959, 1960-1969, 1970-1979, 1980-1989 and 1990-1997). METHODS: Age-specific (10-24 years) smoking initiation rates were calculated by gender, educational level and urbanisation. The multiple logistic models were used for estimates of changes in smoking initiation age. RESULTS: The mean age of smoking initiation decreased substantially from 22.0 years (95% confidence interval [CI]: 21.2-22.7) to 17.5 years (95% CI: 16.2-19.1) over five generations. A large decrease was seen in the initiation age group of 15-24 years in the 1980s cohort (15-19 years: odds ratio [OR] = 0.57; 95% CI: 0.19-0.97; 20-24 years: OR = 0.45; 95% CI: 0.18-0.82); a significant decrease was also found in the 1990s cohort (15-19 years: OR = 0.47; 95% CI: 0.11-0.94; 20-24 years old: OR = 0.34; 95% CI: 0.14-0.85). The peak age of smoking initiation changed from 20 years old to 18 years old over the five generations. CONCLUSIONS: The age of smoking initiation has decreased rapidly in the Chinese population in the past decades. Chinese adolescents are becoming the main target group for the tobacco marketing industry, and national legislations are urgently required.

Sex Differences in Multilevel Factors of Smoking Experimentation and Age of Initiation in Korean Adolescents.

This study purpose was to investigate sex differences in multilevel factors associated with smoking experimentation and age of initiation among Korean adolescents. Based on the ecological model, this cross-sectional study used data from the 2016 Korea Youth Risk Behavior Web-Based Survey (N = 65,528). Among 33,803 males (51.6%) and 31,725 females (48.4%), a greater proportion of males (21.9%) than females (7.1%) engaged in smoking experimentation. Males started smoking earlier than females (males: 12.7 years, females: 12.9 years, respectively, p < .05). In both sex groups, common factors associated with smoking were age, depression, suicidal ideation, academic achievement, household economic status, and having friends smoking and a specific person to talk with about their personal concern (all p values <.05). There were significant sex differences in psychological, family, and school factors of smoking initiation and experimentation. It is necessary to develop smoking interventions considering both individual and environmental factors with sex-specific strategies.

E-Cigarettes: Use, Effects on Smoking, Risks, and Policy Implications.

Since e-cigarettes appeared in the mid-2000s, some practitioners, researchers, and policy makers have embraced them as a safer alternative to conventional cigarettes and an effective way to stop smoking. While e-cigarettes deliver lower levels of carcinogens than do conventional cigarettes, they still expose users to high levels of ultrafine particles and other toxins that may substantially increase cardiovascular and noncancer lung disease risks, which account for more than half of all smoking-caused deaths, at rates similar to conventional cigarettes. Moreover, rather than stimulating smokers to switch from conventional cigarettes to less dangerous e-cigarettes or quitting altogether, e-cigarettes are reducing smoking cessation rates and expanding the nicotine market by attracting youth.

Cross-Cultural Comparison of Genetic and Cultural Transmission of Smoking Initiation Using an Extended Twin Kinship Model.

BACKGROUND: Considerable evidence from twin and adoption studies indicates that genetic and shared environmental factors play a role in the initiation of smoking behavior. Although twin and adoption designs are powerful to detect genetic and environmental influences, they do not provide information on the processes of assortative mating and parent-offspring transmission and their contribution to the variability explained by genetic and/or environmental factors. METHODS: We examined the role of genetic and environmental factors in individual differences for smoking initiation (SI) using an extended kinship design. This design allows the simultaneous testing of additive and non-additive genetic, shared and individual-specific environmental factors, as well as sex differences in the expression of genes and environment in the presence of assortative mating and combined genetic and cultural transmission, while also estimating the regression of the prevalence of SI on age. A dichotomous lifetime 'ever' smoking measure was obtained from twins and relatives in the 'Virginia 30,000' sample and the 'Australian 25,000'. RESULTS: Results demonstrate that both genetic and environmental factors play a significant role in the liability to SI. Major influences on individual differences appeared to be additive genetic and unique environmental effects, with smaller contributions from assortative mating, shared sibling environment, twin environment, cultural transmission, and resulting genotype-environment covariance. Age regression of the prevalence of SI was significant. The finding of negative cultural transmission without dominance led us to investigate more closely two possible mechanisms for the lower parent-offspring correlations compared to the sibling and DZ twin correlations in subsets of the data: (1) age × gene interaction, and (2) social homogamy. Neither of the mechanism provided a significantly better explanation of the data. CONCLUSIONS: This study showed significant heritability, partly due to assortment, and significant effects of primarily non-parental shared environment on liability to SI.

Changes in living arrangement, daily smoking, and risky drinking initiation among young Swiss men: a longitudinal cohort study.

OBJECTIVES: The aim of this study was to assess the association between changes in living arrangement and the initiation of daily smoking and monthly risky single-occasion drinking (RSOD) in a cohort of young Swiss men. STUDY DESIGN: Longitudinal cohort study. METHODS: The sample consisted of 4662 young men drawn from the Cohort Study on Substance Use Risk Factors who lived with their family at baseline. Follow-up assessments occurred 15 months later. Multiple regression models were adjusted for individual and family factors (family model), as well as for individual and peer-related factors (peer model). RESULTS: Relative to those still living with their parents at follow-up (n = 3845), those who had moved out (n = 817) were considerably more likely to have taken up smoking or RSOD after adjusting for several individual, family, and peer-related variables: OR (daily smoking) = 1.67 (95% CI 1.15-2.41) (P = 0.007) and OR (monthly RSOD) = 1.42 (95% CI 1.08-1.88) (P = 0.012). The strongest family-related predictors of smoking initiation were family structure and the lack of parental regulation and the strongest peer-related factors alcohol/drug problems in peers. Meanwhile, the strongest peer-related predictors of RSOD initiation were peer pressure (misconduct), perceived social support from friends, and perceived social support from a significant other, whereas family factors were not associated with RSOD initiation. Further subanalyses were conducted to examine the impact of different living arrangement changes on substance use initiation and revealed that living with peers at follow-up was associated with the greatest risk. CONCLUSIONS: We identified a strong association between moving out of one's parents' home and daily smoking and monthly RSOD initiation in young Swiss men. Moving out to live with peers was an especially strong predictor of substance use initiation. Campaigns that aim to prevent heavy smoking and drinking should be intensified at the end of obligatory school.

Socioeconomic Disparities in Age of Initiation and Ever Tobacco Smoking: Findings from Romania.

AIM: Smoking initiation is considered the fundamental behaviour that determines the future health burden of tobacco smoking in a society. The aim of the study was to evaluate the socio-demographic factors associated with initiation of regular smoking among adults. METHODS: The data source was the 2011 Global Adult Tobacco Survey Romania (GATS), which is a cross-sectional, nationally representative study. Multivariate logistic regression model was applied for relevant analysis. RESULTS: Among males, the regular smoking initiation rate was significantly higher compared to females (52.4% vs. 18.5%; p<0.001). Mean age of smoking initiation was lower in men compared to women (18.4±4.8 vs. 21.5±6.8; p<0.001). Age in men, awareness of environmental tobacco smoke consequences and place of living for women as well as educational attainment and employment status in both genders were associated with ever regular smoking. Moreover, cohabitation with a smoker was associated with greater odds for initiating smoking among both genders. CONCLUSIONS: GATS revealed a significant but diverse role of socioeconomic factors in initiation of regular smoking among adult Romanians.

Long-term effects of a home-based smoking prevention program on smoking initiation: a cluster randomized controlled trial.

OBJECTIVE: The aims of the study were to evaluate the long-term effects of a home-based smoking prevention program 'Smoke-free Kids' during preadolescence on smoking initiation during adolescence and to test the potential moderating role of parental smoking, socioeconomic status, and asthma. METHOD: In 2008, 1478 9-11year old children and their mothers were recruited from 418 elementary schools in the Netherlands. An independent statistician randomly allocated schools to one of the two conditions using a 1:1 ratio (single blind): 728 children in the intervention and 750 in the control condition. The intervention condition received five activity modules, including a communication sheet for mothers, by mail at four-week intervals and one booster module one year after baseline. The control condition received a fact-based intervention only. Intention-to-treat analysis was performed on 1398 non-smoking children at baseline. RESULTS: In the intervention 10.8% of the children started smoking compared to 12% in the control condition. This difference was non-significant (odds ratio=0.90, 95% confidence interval=0.63-1.27). No moderating effects were found. CONCLUSION: No effects on smoking initiation after 36months were found. Perhaps, the program was implemented with children that were too young. Programs closer to the age of smoking onset should be tested.

Smoking initiation among Israeli adolescents: a 24-year time-to-event analysis.

INTRODUCTION: Preventing smoking initiation will protect future generations from smoking-attributable death and disease. This study examines the correlates and patterns of initiation among Israeli youth using time-to-event analysis and other methods. METHODS: Twenty-four consecutive representative samples (1986-2009) of new military recruits (N=50,254) were analyzed. Cox regression and Kaplan-Meier analysis were used to identify factors associated with smoking initiation, and logistic regression was used to identify factors associated with smoking status. RESULTS: The most hazardous age for smoking initiation was seventeen, subsequent to the mean age of smoking initiation (males: 15.7, females: 16.0). Age of initiation and age of greatest hazard for initiation declined among recruits between the years 1986 and 2009. Earlier smoking initiation among boys and girls was significantly associated with low education levels (<12years) (males: HR=2.98, CI: [2.79, 3.18]; females: HR=3.35, CI: [2.96, 3.80]), low paternal education levels, Russian birthplace, and religion. Earlier initiation in boys was associated with high fitness levels and low/medium socio-economic status. Earlier initiation in girls was associated with being Western-born and ever-use of contraception. CONCLUSIONS: Smoking initiation among Israeli youth recruited to the armed forces is associated with individual and family characteristics, particularly low education levels. Time-to-event analysis complements traditional means of understanding smoking initiation by identifying ages at which initiation hazard is high.

The impact of tobacco control expenditures on smoking initiation and cessation.

Between 1997 and 2007, smoking prevalence declined from 33% to 28% in Switzerland. Over the same period, funding for tobacco control activities significantly increased, resulting in the implementation of a large variety of national and regional interventions. In this paper, I exploit variation over time and across cantons of tobacco control expenditures to examine the impact of these policies on smoking decisions. I use retrospective smoking information from the Swiss Health Survey (2007) and find that tobacco control expenditures decreased the probability of smoking initiation among adolescents and young adults and increased cessation rates in the general population of smokers. I estimate that if funding had been kept at the 1997 level, there would have been 107,000 additional smokers in 2007.

Measures of initiation and progression to increased smoking among current menthol compared to non-menthol cigarette smokers based on data from four U.S. government surveys.

There are no large-scale, carefully designed cohort studies that provide evidence on whether menthol cigarette use is associated with a differential risk of initiating and/or progressing to increased smoking. However, questions of whether current menthol cigarette smokers initiated smoking at a younger age or are more likely to have transitioned from non-daily to daily cigarette use compared to non-menthol smokers can be addressed using cross-sectional data from U.S. government surveys. Analyses of nationally representative samples of adult and youth smokers indicate that current menthol cigarette use is not associated with an earlier age of having initiated smoking or greater likelihood of being a daily versus non-daily smoker. Some surveys likewise provide information on cigarette type preference (menthol versus non-menthol) among youth at different stages or trajectories of smoking, based on number of days smoked during the past month and/or cigarettes smoked per day. Prevalence of menthol cigarette use does not appear to differ among new, less experienced youth smokers compared to established youth smokers. While there are limitations with regard to inferences that can be drawn from cross-sectional analyses, these data do not suggest any adverse effects for menthol cigarettes on measures of initiation and progression to increased smoking.