Effectiveness of e-cigarettes as aids for smoking cessation: evidence from the PATH Study cohort, 2017-2019.

OBJECTIVE: To assess the effectiveness of e-cigarettes in smoking cessation in the USA from 2017 to 2019, given the 2017 increase in high nicotine e-cigarette sales. METHODS: In 2017, the PATH Cohort Study included data on 3578 previous year smokers with a recent quit attempt and 1323 recent former smokers. Respondents reported e-cigarettes or other products used to quit cigarettes and many covariates associated with e-cigarette use. Study outcomes were 12+ months of cigarette abstinence and tobacco abstinence in 2019. We report weighted unadjusted estimates and use propensity score matched analyses with 1500 bootstrap samples to estimate adjusted risk differences (aRD). RESULTS: In 2017, 12.6% (95% CI 11.3% to 13.9%) of recent quit attempters used e-cigarettes to help with their quit attempt, a decline from previous years. Cigarette abstinence for e-cigarette users (9.9%, 95% CI 6.6% to 13.2%) was lower than for no product use (18.6%, 95% CI 16.0% to 21.2%), and the aRD for e-cigarettes versus pharmaceutical aids was -7.3% (95% CI -14.4 to -0.4) and for e-cigarettes versus any other method was -7.7% (95% CI -12.2 to -3.2). Only 2.2% (95% CI 0.0% to 4.4%) of recent former smokers switched to a high nicotine e-cigarette. Subjects who switched to e-cigarettes appeared to have a higher relapse rate than those who did not switch to e-cigarettes or other tobacco, although the difference was not statistically significant. CONCLUSIONS: Sales increases in high nicotine e-cigarettes in 2017 did not translate to more smokers using these e-cigarettes to quit smoking. On average, using e-cigarettes for cessation in 2017 did not improve successful quitting or prevent relapse.

Racial/Ethnic Disparities Across Indicators of Cigarette Smoking in the Era of Increased Tobacco Control, 1992-2019.

INTRODUCTION: This study compared tobacco use and cessation for African Americans (AA), Asians/Pacific Islanders (API), Hispanics/Latinos (H/L), American Indian/Alaskan Natives (AI/AN), and non-Hispanic Whites (NHW) in the United States to California (CA), the state with the longest continually funded tobacco control program. The purpose of this study was to identify tobacco use disparities across racial/ethnic groups across time. METHODS: Cigarette use prevalence (uptake and current use), consumption (mean number of cigarettes smoked per day [CPD]), and quit ratios were calculated across survey years, and trends were examined within each race/ethnic group and comparing between CA and the United States, utilizing the 1992-2019 Tobacco Use Supplements to the Current Population Survey. RESULTS: Prevalence decreased for all race/ethnic groups. Current use among CA NHW showed significant decline compared with US counterparts, whereas US H/L showed greater decline than CA counterparts. CPD decreased by approximately 30% across race/ethnic groups, with CA groups having lower numbers. The greatest decrease occurred among AA in CA (average 10.3 CPD [95% confidence interval (CI): 10.3, 12.6] in 1992/1993 to 3 CPD [95% CI: 2.4, 3.7] in 2018/2019). Quit ratios increased from 1992/1993 to 2018/2019 for CA H/L 52.4% (95% CI: 49.8, 53.0) to 59.3 (95% CI: 55.8, 62.5) and CA NHWs 61.5% (95% CI: 60.7, 61.9) to 63.8% (95% CI: 63.9, 66.9). CONCLUSIONS: Although overall prevalence decreased over time for each racial/ethnic group, declines in CA outpaced the United States only for NHWs. Reductions in CPD were encouraging but the quit ratio points to the need to increase tobacco control efforts toward cessation. IMPLICATIONS: The successes in reduced cigarette use uptake and prevalence across time for both California and the rest of the United States were observed largely among non-Hispanic White populations. Although reductions in the number of cigarettes smoked per day are a notable success, particularly among the Californian African Americans, efforts to support quitting across racial/ethnic groups, especially marginalized groups, need to be prioritized.

Use of Electronic Cigarettes to Aid Long-Term Smoking Cessation in the United States: Prospective Evidence From the PATH Cohort Study.

Electronic cigarettes (e-cigarettes) are the preferred smoking-cessation aid in the United States; however, there is little evidence regarding long-term effectiveness among those who use them. We used the Population Assessment of Tobacco and Health Study to compare long-term abstinence between matched US smokers who tried to quit with and without use of e-cigarettes as a cessation aid. We identified a nationally representative cohort of 2,535 adult US smokers in 2014-2015 (baseline assessment), who, in 2015-2016 (exposure assessment), reported a past-year attempt to quit and the cessation aids used, and reported smoking status in 2016-2017 (outcome assessment; self-reported ≥12 months continuous abstinence). We used propensity-score methods to match each e-cigarette user with similar nonusers. Among US smokers who used e-cigarettes to help quit, 12.9% (95% confidence interval (CI): 9.1%, 16.7%) successfully attained long-term abstinence. However, there was no difference compared with matched non-e-cigarette users (cigarette abstinence difference: 2%; 95% CI: -3%, 7%). Furthermore, fewer e-cigarette users were abstinent from nicotine products in the long term (nicotine abstinence difference: -4%; 95% CI: -7%, -1%); approximately two-thirds of e-cigarette users who successfully quit smoking continued to use e-cigarettes. These results suggest e-cigarettes may not be an effective cessation aid for adult smokers and, instead, may contribute to continuing nicotine dependence.

Widening disparities in cigarette smoking by race/ethnicity across education level in the United States.

Reducing tobacco use is an important public health objective. It is the largest preventable cause of death and disease, yet inequalities remain. This study examines combined educational and racial/ethnic disparities in the United States related to cigarette smoking for the three largest racial/ethnic groups (African Americans, Hispanics/Latinos, and non-Hispanic Whites). Data included nine Tobacco Use Supplements to the Current Population Surveys (TUS-CPS) conducted in the United States from 1992/1993-2018 for four smoking metrics: ever smoking rates, current smoking rates, consumption (cigarettes per day), and quit ratios. Across all TUS-CPS samples, there were 9.5% African Americans, 8.8% Hispanics/Latinos, and 81.8% non-Hispanic Whites who completed surveys. Findings revealed that lower educational attainment was associated with increased ever and current smoking prevalence over time across all racial/ethnic groups, and education-level disparities within each race/ethnicity widened over time. Disparities in ever and current smoking rates between the lowest and highest categories of educational attainment (less than a high school education vs. completion of college) were larger for African Americans and non-Hispanic Whites than Hispanics/Latinos. Non-Hispanic Whites had the highest cigarette consumption across all education levels over time. College graduates had the highest quit ratios for all racial/ethnic groups from 1992 to 2018, with quit ratios significantly increasing for Hispanics/Latinos and non-Hispanic Whites, but not African Americans. In conclusion, educational disparities in smoking have worsened over time, especially among African Americans and Hispanics/Latinos. Targeted tobacco control efforts could help reduce these disparities to meet public health objectives, although racial/ethnic disparities may persist regardless of educational attainment.

Can E-Cigarettes and Pharmaceutical Aids Increase Smoking Cessation and Reduce Cigarette Consumption? Findings From a Nationally Representative Cohort of American Smokers.

Many smokers believe that electronic nicotine delivery systems (ENDS) and pharmaceutical cessation aids can help them quit smoking or reduce cigarette consumption, but the evidence for e-cigarettes to aid quitting is limited. Examining 3,093 quit attempters in the nationally representative US Population Assessment of Tobacco and Health (PATH) Study, using data from 2013-2015, we evaluated the influence of ENDS and pharmaceutical cessation aids on persistent abstinence (≥30 days) from cigarettes and reduced cigarette consumption, using propensity score matching to balance comparison groups on potential confounders and multiple imputation to handle missing data. At PATH Wave 2, 25.2% of quit attempters reported using ENDS to quit during the previous year, making it the most popular cessation aid in 2014-2015. More quit attempters were persistently cigarette abstinent than were persistently tobacco abstinent (15.5% (standard error, 0.8) vs. 9.6% (standard error, 0.6)). Using ENDS to quit cigarettes increased the probability of persistent cigarette abstinence at Wave 2 (risk difference (RD) = 6%, 95% confidence interval (CI): 2, 10), but using approved pharmaceutical aids did not (for varenicline, RD = 2%, 95% CI: -6, 13; for bupropion, RD = 4%, 95% CI: -6, 17; for nicotine replacement therapy, RD = -3%, 95% CI: -8, 2). Among quit attempters who relapsed, ENDS did not reduce the average daily cigarette consumption (cigarettes per day, -0.18, 95% CI: -1.87, 1.51).

Tobacco control in California compared with the rest of the USA: trends in adult per capita cigarette consumption.

BACKGROUND: In the 1990s, California led the USA in state-level tobacco control strategies. However, after 2000, California lost ground on cigarette taxes, although it maintained higher levels of smoke-free homes among smokers. METHODS: Trends in per capita cigarette consumption were assessed through taxed sales data and from self-report in repeated national cross-sectional surveys. Linear regressions identified changes in trends after year 2000 separately for California and the rest of the USA. Using data from each state, a linear regression tested the association between different tobacco control strategies and per capita consumption. Change in self-reported per capita consumption was partitioned into contributions associated with initiation, quitting and reduction in cigarette consumption level. RESULTS: Both taxed cigarette sales and per capita consumption declined rapidly in the USA from 1985 to 2015. Declines were particularly fast in California before 2000 but slowed thereafter. In 2014, per capita consumption in California was 29.4 packs/adult/year, but 90% higher in the rest of the USA. Modelling state-level data, every $1 increase in cigarette taxes reduced consumption by 4.8 (95% CI 2.9 to 6.8) packs/adult/year. Every 5% increase in the proportion of smokers with smoke-free homes reduced consumption by 8.0 (95% CI 7.0 to 8.9) packs/adult/year. The different patterns in California and the rest of the USA are at least partially explained by these two variables. The slow down in per capita consumption in California can be attributed to changes in initiation, quitting and especially smokers reducing their consumption level. CONCLUSIONS: Tobacco control strategies need to be continually updated to maintain momentum towards a smoke-free society.

Pre-adolescent Receptivity to Tobacco Marketing and Its Relationship to Acquiring Friends Who Smoke and Cigarette Smoking Initiation.

BACKGROUND: This study extends research on receptivity to tobacco marketing over a key developmental period for cigarette smoking experimentation. PURPOSE: The purpose of this study was to understand the effect of receptivity to tobacco marketing and exposure to friends who smoke on smoking experimentation. METHODS: Participants were 10 to 13 years old who had never tried cigarettes (n = 878), interviewed six times at 8-month intervals. RESULTS: At baseline, 25% percent of the 10 and 11 years old in the sample of never smokers were receptive to tobacco marketing, while less than 5% had friends who smoked. Having a friend who smoked at study baseline and acquiring such friends for the first time during the study were the strongest predictors of smoking experimentation. Initial receptivity to tobacco marketing increased the risk of smoking experimentation independently of having friends who smoke at baseline or acquiring friends who smoke throughout the study period. CONCLUSIONS: The high level of receptivity observed even among 10 and 11 years old and its robust relationship with cigarette smoking experimentation independent of the significant risk associated with having friends who smoke suggests that successful prevention of receptivity may require intervention at an early age.

Susceptibility to tobacco product use among youth in wave 1 of the population Assessment of tobacco and health (PATH) study.

The purpose of this study was to investigate susceptibility and ever use of tobacco products among adolescents and young adults in the US. Cross-sectional analysis of Wave 1(2013-2014) adolescent (12-17year-olds; n=13,651) and young adult (18-24year-olds; n=9112) data from the nationally-representative Population Assessment of Tobacco and Health (PATH) Study was conducted. At 12years, 5% were ever tobacco users and 36% were susceptible to use. Seventy percent were susceptible at age 17years, and the same proportion were ever users at age 22years. Susceptibility levels were comparable for cigarettes and e-cigarette (28.6% and 27.4%, respectively), followed by hookah (22.0%), pipes (17.5%), cigars (15.2%), and smokeless tobacco (9.7%). Non-Hispanic (NH) Black (Adjusted Odds Ratio [ORadj]=1.36; 95% Confidence Limit [CL], 1.18-1.56) and Hispanic (ORadj=1.34: 95% CL,1.19-1.49) adolescent never- users were more likely to be susceptible to future use of a tobacco product than NH Whites. Susceptibility was higher with age (15-17yrs. vs 12-14yrs.: ORadj=1.69; 95% CL, 1.55-1.85) and parental education (college graduates vs less than HS education: ORadj=1.22, 95% CL, 1.08-1.39). Compared to exclusive users of hookah, cigars, or smokeless products, larger proportions of exclusive e-cigarette ever users were also susceptible to cigarette use. Among adolescents, lower levels of ever use of tobacco products are often counterbalanced by higher levels of susceptibility for future use, which may suggest delayed initiation in some groups. Ever users of a given tobacco product were more susceptible to use other tobacco products, putting them at risk for future multiple tobacco product use.

Trends in use of little cigars or cigarillos and cigarettes among U.S. smokers, 2002-2011.

OBJECTIVES: Little cigars and cigarillos may resemble cigarettes, but may be less expensive and can be purchased singly and in flavored varieties. We used two major U.S. surveys to investigate use of cigarillos and cigarettes. METHODS: The 2010/2011 Tobacco Use Supplement to the Current Population Survey ascertained cigar use by brand and type (little cigars/cigarillos or large/regular). The annual National Survey on Drug Use and Health (NSDUH) assessed cigar use by brand, 2002-2011. We used the available data to classify cigars by type among males in the NSDUH. RESULTS: Estimated prevalence of little cigar use among male cigar smokers was similar using the two surveys. From 2002 to 2011, past-30-day cigarette smoking declined for all age groups and genders, but among young adult men (aged 18-25) little cigar smoking remained steady at nearly 9%. "Cigarette and/or cigar" smoking was 44% among young adult men in 2011, and was consistently 6 percentage points higher than cigarette-only smoking, from 2002 to 2011. Over 60% of male and 70% of female adolescent/young adult cigar smokers also smoked cigarettes in 2011. Most male adolescents preferred little cigars to traditional cigars. Among males, most lower income or less educated cigar smokers preferred little cigars, compared to only 16% of those with higher education. CONCLUSIONS: These patterns indicate that little cigar/cigarillo use may promote initiation and maintenance of cigarette smoking, particularly among younger and less advantaged populations. Population-level data are urgently needed to better assess type of cigar smoked and reasons for use.

Wearable Sensor/Device (Fitbit One) and SMS Text-Messaging Prompts to Increase Physical Activity in Overweight and Obese Adults: A Randomized Controlled Trial.

BACKGROUND: Studies have shown self-monitoring can modify health behaviors, including physical activity (PA). This study tested the utility of a wearable sensor/device (Fitbit(®) One™; Fitbit Inc., San Francisco, CA) and short message service (SMS) text-messaging prompts to increase PA in overweight and obese adults. MATERIALS AND METHODS: Sixty-seven adults wore a Fitbit One tracker for 6 weeks; half were randomized to also receive three daily SMS-based PA prompts. The Fitbit One consisted of a wearable tracker for instant feedback on performance and a Web site/mobile application (app) for detailed summaries. Outcome measures were objectively measured steps and minutes of PA by intensity using two accelerometers: Actigraph™ (Pensacola, FL) GT3X+ (primary measure) at baseline and Week 6 and Fitbit One (secondary measure) at baseline and Weeks 1, 2, 3, 4, 5, and 6. RESULTS: Mixed-model repeated-measures analysis of primary measures indicated a significant within-group increase of +4.3 (standard error [SE]=2.0) min/week of moderate- to vigorous-intensity PA (MVPA) at 6-week follow-up (p=0.04) in the comparison group (Fitbit only), but no study group differences across PA levels. Secondary measures indicated the SMS text-messaging effect lasted for only 1 week: the intervention group increased by +1,266 steps (SE=491; p=0.01), +17.8 min/week MVPA (SE=8.5; p=0.04), and +38.3 min/week total PA (SE=15.9; p=0.02) compared with no changes in the comparison group, and these between-group differences were significant for steps (p=0.01), fairly/very active minutes (p<0.01), and total active minutes (p=0.02). CONCLUSIONS: These data suggest that the Fitbit One achieved a small increase in MVPA at follow-up and that the SMS-based PA prompts were insufficient in increasing PA beyond 1 week. Future studies can test this intervention in those requiring less help and/or test strategies to increase participants' engagement levels.

National trends in smoking behaviors among Mexican, Puerto Rican, and Cuban men and women in the United States.

OBJECTIVES: We examined trends in smoking behaviors across 2 periods among Mexicans, Puerto Ricans, and Cubans in the United States. METHODS: We analyzed data from the 1992-2007 Tobacco Use Supplements to the Current Population Survey. We constructed 2 data sets (1990s vs 2000s) to compare smoking behaviors between the 2 periods. RESULTS: Significant decreases in ever, current, and heavy smoking were accompanied by increases in light and intermittent smoking across periods for all Latino groups, although current smoking rates among Puerto Rican women did not decline. Adjusted logistic regression models revealed that in the 2000s, younger Mexicans and those interviewed in English were more likely to be light and intermittent smokers. Mexican and Cuban light and intermittent smokers were less likely to be advised by healthcare professionals to quit smoking. Mexicans and Puerto Ricans who were unemployed and Mexicans who worked outdoors were more likely to be heavy smokers. CONCLUSIONS: Increases in light and intermittent smoking among Mexican, Puerto Rican, and Cuban Americans suggest that targeted efforts to further reduce smoking among Latinos may benefit by focusing on such smokers.

Increases in light and intermittent smoking among Asian Americans and non-Hispanic Whites.

INTRODUCTION: Asian Americans are the fastest growing immigrant group in the United States and are more likely to be light and intermittent smokers (LITS) compared with non-Hispanic Whites (NHWs). LITS experience adverse health effects related to smoking. Previous research has aggregated Asian American ethnic groups, masking important differences between groups. We sought to compare LITS rates among Asian American subgroups before and after the 1998 Master Settlement Agreement (MSA) with NHWs in California utilizing data from the California Tobacco Surveys (CTS). METHODS: We combined 1990, 1992, and 1996 CTS (pre-MSA) and the 1999, 2002, 2005, and 2008 CTS (post-MSA) to examine changes in LITS (<10 cigarettes/day or not smoking daily). Chinese, Filipino, Japanese, and Korean ethnic groups were compared with NHWs. RESULTS: Pre-MSA logistic regression models adjusted for age, gender, education level, language spoken at home, and use of other tobacco products found that Chinese (odds ratio [OR] = 3.38, 95% confidence interval [CI] = 2.19, 5.21), Filipinos (OR = 3.55, 95% CI = 2.73, 4.63), Japanese (OR = 1.99, 95% CI = 1.22, 3.27), and Koreans (OR = 3.22, 95% CI = 2.06, 5.03) were significantly more likely to be LITS compared with NHWs. Post-MSA, all Asian American subgroups experienced an increase in LITS (11.7%-37.8%); however, only Chinese (OR = 2.19, 95% CI = 1.16, 4.13) and Filipinos (OR = 3.33, 95% CI = 2.26, 4.91) remained significantly more likely to be LITS compared with NHWs. CONCLUSIONS: Our results highlight the need for tobacco control efforts that address the growing group of LITS among Asian Americans and NHWs.

The effectiveness of cigarette price and smoke-free homes on low-income smokers in the United States.

OBJECTIVES: We examined the effectiveness of state cigarette price and smoke-free homes on smoking behaviors of low-income and high-income populations in the United States. METHODS: We used the 2006-2007 Tobacco Use Supplement to the Current Population Survey. The primary outcomes were average daily cigarette consumption and successful quitting. We used multivariable regression to examine the association of cigarette price and smoke-free home policies on these outcomes. RESULTS: High state cigarette price (pack price ≥ $4.50) was associated with lower consumption across all income levels. Although low-income individuals were least likely to adopt smoke-free homes, those who adopted them had consumption levels and successful quit rates that were similar to those among higher-income individuals. In multivariable analysis, both policies were independently associated with lower consumption, but only smoke-free homes were associated with sustained cessation at 90 days. CONCLUSIONS: High cigarette prices and especially smoke-free homes have the potential to reduce smoking behaviors among low-income individuals. Interventions are needed to increase adoption of smoke-free homes among low-income populations to increase cessation rates and prevent relapse.

Quitlines and nicotine replacement for smoking cessation: do we need to change policy?

In the past 20 years, public health initiatives on smoking cessation have increased substantially. Randomized trials indicate that pharmaceutical cessation aids can increase success by 50% among heavier smokers who seek help, and use of these aids has increased markedly. Quitlines provide a portal through which smokers can seek assistance to quit and are promoted by tobacco control programs. Randomized trials have demonstrated that telephone coaching following a quitline call can also increase quitting, and a combination of quitlines, pharmaceutical aids and physician monitoring can help heavier smokers to quit. While quit attempts have increased, widespread dissemination of these aids has not improved population success rates. Pharmaceutical marketing strategies may have reduced expectations of the difficulty of quitting, reducing success per attempt. Some policies actively discourage unassisted smoking cessation despite the documented high success rates of this approach. There is an urgent need to revisit public policy on smoking cessation.

Daily E-cigarette Use and the Surge in JUUL Sales: 2017-2019.

OBJECTIVES: To identify how the 2017 rapid surge in sales of JUUL e-cigarettes affected usage among US youth and young adults. METHODS: Annual surveys in the Population Assessment of Tobacco and Health Study assess tobacco use by product and brand among the US population. We identified 2 cohorts aged 14 to 34 years, 1 with baseline survey in 2014 before the rapid surge of JUUL and the other in 2017 as the surge in JUUL sales was occurring. For 5 age groups, we compared 2-year incidence of first tobacco use and of new-onset daily tobacco use by product, and report levels of dependence. RESULTS: Sociodemographic variables and rates of experimentation with any tobacco product were similar between cohorts. Among baseline nondaily tobacco users, only those aged 14 to 17 years had an increase in the 2-year incidence of new daily tobacco use (2014 cohort = 4.8%, 95% confidence interval 4.3, 5.5 vs 2017 cohort = 6.3%, 95% confidence interval 5.8-7.0) to rates approaching those in the 1990s. In 2019, three-quarters of new daily tobacco users aged 14 to 17 vaped daily and had e-cigarette dependence scores similar to daily cigarette smokers and older adult e-cigarette vapers. We estimate that about 600 000 Americans aged <21 years used JUUL products daily in 2019, a rate 2.5 times those aged 25 to 34 years. CONCLUSIONS: The surge in US JUUL sales was associated with a sharp rise in daily e-cigarette vaping and daily tobacco use among US youth, not young adults.

A nationwide analysis of US racial/ethnic disparities in smoking behaviors, smoking cessation, and cessation-related factors.

OBJECTIVES: We used nationally representative data to examine racial/ethnic disparities in smoking behaviors, smoking cessation, and factors associated with cessation among US adults. METHODS: We analyzed data on adults aged 20 to 64 years from the 2003 Tobacco Use Supplement to the Current Population Survey, and we examined associations by fitting adjusted logistic regression models to the data. RESULTS: Compared with non-Hispanic Whites, smaller proportions of African Americans, Asian Americans/Pacific Islanders, and Hispanics/Latinos had ever smoked. Significantly fewer African Americans reported long-term quitting. Racial/ethnic minorities were more likely to be light and intermittent smokers and less likely to smoke within 30 minutes of waking. Adjusted models revealed that racial/ethnic minorities were not less likely to receive advice from health professionals to quit smoking, but they were less likely to use nicotine replacement therapy. CONCLUSIONS: Specific needs and ideal program focuses for cessation may vary across racial/ethnic groups, such that approaches tailored by race/ethnicity might be optimal. Traditional conceptualizations of cigarette addiction and the quitting process may need to be revised for racial/ethnic minority smokers.

Increasing hookah use in California.

Hookah use is gaining popularity nationwide. We determined the correlates and trends for hookah use from the California Tobacco Survey. Between 2005 and 2008 hookah use increased more than 40%, and in 2008, 24.5% of young men reported ever using a hookah. Hookah use was more common among the young (18-24 years), the educated, the non-Hispanic Whites, and the cigarette smokers. Hookah use is increasing in California, especially among young adults, and in 2008 reached the highest prevalence ever reported for both genders.

Prevalence of heavy smoking in California and the United States, 1965-2007.

CONTEXT: The intensity of smoking, not just prevalence, is associated with future health consequences. OBJECTIVE: To estimate smoking intensity patterns over time and by age within birth cohorts for California and the remaining United States. DESIGN, SETTING, AND PARTICIPANTS: Two large population-based surveys with state estimates: National Health Interview Surveys, 1965-1994; and Current Population Survey Tobacco Supplements, 1992-2007. There were 139,176 total respondents for California and 1,662,353 for the remaining United States. MAIN OUTCOME MEASURE: Number of cigarettes smoked per day (CPD), high-intensity smokers (≥20 CPD); moderate-intensity smokers (10-19 CPD); low-intensity smokers (0-9 CPD). RESULTS: In 1965, 23.2% of adults in California (95% confidence interval [CI], 19.6%-26.8%) and 22.9% of adults in the remaining United States (95% CI, 22.1%-23.6%) were high-intensity smokers, representing 56% of all smokers. By 2007, this prevalence was 2.6% (95% CI, 0.0%-5.6%) or 23% of smokers in California and 7.2% (95% CI, 6.4%-8.0%) or 40% of smokers in the remaining United States. Among individuals (US residents excluding California) born between 1920-1929, the prevalence of moderate/high-intensity smoking (≥10 CPD) was 40.5% (95% CI, 38.3%-42.7%) in 1965. Moderate/high-intensity smoking declined across successive birth cohorts, and for the 1970-1979 birth cohort, the highest rate of moderate/high-intensity smoking was 9.7% (95% CI, 7.7%-11.7%) in California and 18.3% (95% CI, 16.4%-20.2%) in the remaining United States. There was a marked decline in moderate/high-intensity smoking at older ages in all cohorts, but this was greater in California. By age 35 years, the prevalence of moderate/high-intensity smoking in the 1970-1979 birth cohort was 4.6% (95% CI, 3.0%-6.1%) in California and 13.5% (95% CI, 11.8%-15.1%) in the remaining United States. CONCLUSIONS: Between 1965 and 2007, the prevalence of high-intensity smoking decreased greatly in the United States. The greater decline in high-intensity smoking prevalence in California was related to reduced smoking initiation and a probable increase in smoking cessation.

Use of E-cigarettes and Other Tobacco Products and Progression to Daily Cigarette Smoking.

OBJECTIVES: To identify predictors of becoming a daily cigarette smoker over the course of 4 years. METHODS: We identified 12- to 24-year-olds at wave 1 of the US Population Assessment of Tobacco and Health Study and determined ever use, age at first use, and daily use through wave 4 for 12 tobacco products. RESULTS: Sixty-two percent of 12- to 24-year-olds (95% confidence interval [CI]: 60.1% to 63.2%) tried tobacco, and 30.2% (95% CI: 28.7% to 31.6%) tried ≥5 tobacco products by wave 4. At wave 4, 12% were daily tobacco users, of whom 70% were daily cigarette smokers (95% CI: 67.4% to 73.0%); daily cigarette smoking was 20.8% in 25- to 28-year-olds (95% CI: 18.9% to 22.9%), whereas daily electronic cigarette (e-cigarette) vaping was 3.3% (95% CI: 2.4% to 4.4%). Compared with single product triers, the risk of progressing to daily cigarette smoking was 15 percentage points higher (adjusted risk difference [aRD] 15%; 95% CI: 12% to 18%) among those who tried ≥5 products. In particular, e-cigarette use increased the risk of later daily cigarette smoking by threefold (3% vs 10%; aRD 7%; 95% CI: 6% to 9%). Daily smoking was 6 percentage points lower (aRD -6%; 95% CI: -8% to -4%) for those who experimented after age 18 years. CONCLUSIONS: Trying e-cigarettes and multiple other tobacco products before age 18 years is strongly associated with later daily cigarette smoking. The recent large increase in e-cigarette use will likely reverse the decline in cigarette smoking among US young adults.