Ralph S. Caraballo

Optimal Serum Cotinine Levels for Distinguishing Cigarette Smokers and Nonsmokers Within Different Racial/Ethnic Groups in the United States Between 1999 and 2004

Cotinine, a metabolite of nicotine, is widely used to distinguish smokers from nonsmokers in epidemiologic studies and smoking-cessation clinical trials. As the magnitude of secondhand smoke exposure declines because of proportionally fewer smokers and more clean-indoor-air regulations, the optimal cotinine cutpoint with which to distinguish smokers from nonsmokers is expected to change. The authors analyzed data on 3,078 smokers and 13,078 nonsmokers from the National Health and Nutrition Examination Survey for 1999-2004. Optimal serum cotinine concentrations for discriminating smokers from nonsmokers were determined using receiver operator characteristic curve analysis. Optimal cotinine cutpoints were 3.08 ng/mL (sensitivity = 96.3%, specificity = 97.4%) and 2.99 ng/mL (sensitivity = 86.5%, specificity = 93.1%) for adults and adolescents, respectively. Among adults, optimal cutpoints differed by race/ethnicity: They were 5.92 ng/mL, 4.85 ng/mL, and 0.84 ng/mL for non-Hispanic blacks, non-Hispanic whites, and Mexican Americans, respectively. Among adolescents, cutpoints were 2.77 ng/mL, 2.95 ng/mL, and 1.18 ng/mL for non-Hispanic blacks, non-Hispanic whites, and Mexican Americans, respectively. Use of the currently accepted cutpoint of 14 ng/mL overestimates the number of nonsmokers in comparison with the proposed new overall cutpoint of 3 ng/mL or the race/ethnicity-specific cutpoints of 1-6 ng/mL.

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.

Self-reported cigarette smoking vs. serum cotinine among U.S. adolescents

No national data have been used to compare self-reported and biochemically assessed cigarette smoking status among adolescents. We investigated discrepancies between self-reported smoking and measurement of serum cotinine concentration among adolescents aged 12-17 years in a representative sample (n=2,107) of the U.S. population. Smoking prevalence was 12.9% among teens who reported in a private interview whether they smoked during the previous 5 days (95% CI=10.9%-14.9%) and 12.5% (95% CI=10.3%-14.7%) according to serum cotinine concentration greater than 11.40 ng/ml (the cutpoint). Among teens who reported being a nonsmoker (i.e., that they did not smoke during the previous 5 days), 2.7% (95% CI=1.6%-3.8%) had a serum cotinine concentration of greater than 11.40 ng/ml. Discrepancies among self-reported nonsmokers were less likely among Mexican Americans than among Whites. Among self-reported smokers, 21.1% (95% CI=13.7%-28.5%) had a serum cotinine concentration of 11.40 ng/ml or less. This discrepancy is explained primarily by the high proportion (37.0%) of teen smokers who reported smoking, on average, less than 1 cigarette per day. We believe that social stigma or fear that their parents would find out about their survey responses may be the main explanation for the 2.7% discrepancy among self-reported nonsmokers, and that smoking patterns (including the extent of nicotine dosing) and a lack of measurement of recency of cigarette smoking are the main explanations for the 21.1% discrepancy among self-reported smokers. Efforts to improve the validity of self-reported cigarette smoking will benefit tobacco-related surveillance, evaluation, and research activities for adolescents.

Associations between smoking cessation and anxiety and depression among U.S. adults

Many studies have shown a relationship between smoking and depression. However, few studies have examined the association between current depression and smoking and even fewer used large cross-sectional data to support these findings. Using the 2006 Behavioral Risk Factor Surveillance System data (n=248,800), we compared rates of lifetime depression, lifetime anxiety, current depression, and current depressive symptoms among smokers who unsuccessfully attempted to quit (unsuccessful quitters), former smokers (successful quitters), and smokers who made no attempts to quit (non-quitters). Unsuccessful quitters experienced more lifetime depression and anxiety than non-quitters (OR=1.2; 95% CI, 1.0-1.4), whereas successful quitters experienced less (OR=0.7, 95% CI, 0.6-0.8). Current depression prevalence was 14.3% among non-quitters, 18.8% among unsuccessful quitters, and 8.0% among successful quitters. On average, unsuccessful quitters also experienced more days of depressive symptoms during the previous month than either non-quitters or successful quitters. Our results suggest that smokers who attempt to quit unsuccessfully may experience lifetime depression as well as current depression at a higher rate than other smokers and former smokers.

Time to First Cigarette after Waking Predicts Cotinine Levels

There is wide variability in cotinine levels per cigarette smoked. We hypothesized that in addition to smoking frequency, other behavioral measures of nicotine dependence, such as the time to first cigarette after waking, are associated with cotinine levels. To test this hypothesis, we measured plasma and urinary cotinine in a community-based study of 252 black and white daily cigarette smokers. Among one pack per day smokers, plasma cotinine levels varied from 16 to 1,180 ng/mL, a 74-fold difference. Two nicotine dependence phenotypes were discerned by time after waking. Subjects in the “low” dependent phenotype smoked >30 minutes after waking and nearly all smoked ≤20 cigarettes per day. Cotinine levels increased linearly with cigarette consumption in this group. Subjects in the “high” dependent phenotype smoked ≤30 minutes after waking but had a wide range in the frequency of daily cigarettes (6-70). Compared with the low dependent phenotype, there were relatively small differences in cotinine by cigarette frequency with evidence of a plateau effect in heavy smokers (∼30). After adjusting for cigarette frequency, the levels of cotinine by time to first cigarette were as follows: ≤5 minutes, 437 [95% confidence limits (CL), 380-494]; 6 to 30 minutes, 352 (95% CL, 291-413), 31 to 60 minutes, 229 (95% CL, 140-317), and >60 minutes, 215 (95% CL, 110-321). Similar findings were observed for urinary cotinine. These findings suggest that the time to first cigarette is a strong predictor of nicotine uptake and should be considered in the design of smoking interventions. (Cancer Epidemiol Biomarkers Prev 2009;18(12):3415–20)

Epidemiology of menthol cigarette use in the United States.

BackgroundApproximately one-fourth of all cigarettes sold in the United States have the descriptor “menthol” on the cigarette pack. It is important to determine what socio-demographic factors are associated with smoking menthol cigarettes if indeed these types of cigarettes are related to smoking initiation, higher exposure to smoke constituents, nicotine dependence, or reduced smoking cessation.MethodsThe National Cancer Institute (NCI) conducted a review of the scientific literature on this topic which we completed by adding more recently published articles via PubMed. We also conducted further data analyses using the National Survey on Drug Use and Health, the National Youth Tobacco Survey, the Monitoring the Future Survey, and the National Health and Nutrition Examination Survey to provide up-to-date information on this topic.ResultsMenthol cigarettes are disproportionately smoked by adolescents, blacks/African Americans, adult females, those living in the Northeast of the United States and those with family incomes lower than

Exposure to secondhand smoke in the workplace: serum cotinine by occupation.

50,000. Based on self-reports of menthol cigarette use, menthol cigarette use among smokers have increased from 2004 to 2008. However, no increase was observed during these years for predominantly menthol brands like Newport™, Kool,™ and Salem™, however, this lack of significant trend may be due, at least in part, due to smaller numbers of smokers of specific brands or sub-brands, which provide estimates which are less precise.ConclusionMenthol cigarettes are disproportionately smoked by groups of U.S. cigarette smokers. It is likely that other disparities in menthol cigarette use exist that we have not covered or have not been studied yet.

A Comprehensive Examination of the Influence of State Tobacco Control Programs and Policies on Youth Smoking

To examine workplace exposure to secondhand smoke by occupation, we analyzed data from The Third National Health and Nutrition Examination Survey (NHANES III) (1988 to 1994), a nationally representative sample of the noninstitutionalized population. The analysis was restricted to 4952 employed nonsmoking adults who reported no home exposure to cigarette smoke. Occupations were assigned to 40 groups and 7 categories. Among the categories, geometric mean serum cotinine (ng/mL) ranged from 0.09 for farming/forestry/fishing occupations to 0.22 for operators/fabricators/laborers (median, 0.16). The lowest values were observed among farmers and nursery workers (0.06) and the highest among waiters (0.47). Between 1988 to 1991 and 1991 to 1994, the overall geometric mean cotinine and the proportion reporting that they could smell smoke at work decreased significantly. In conclusion, workplace exposure to secondhand smoke varied by occupation, and decreases in exposure occurred between 1988 to 1991 and 1991 to 1994.

Linking quantity and frequency profiles of cigarette smoking to the presence of nicotine dependence symptoms among adolescent smokers: findings from the 2004 National Youth Tobacco Survey.

OBJECTIVES We examined the influence of tobacco control policies (tobacco control program expenditures, smoke-free air laws, youth access law compliance, and cigarette prices) on youth smoking outcomes (smoking susceptibility, past-year initiation, current smoking, and established smoking). METHODS We combined data from the 2002 to 2008 National Surveys on Drug Use and Health with state and municipality population data from the US Census Bureau to assess the associations between state tobacco control policy variables and youth smoking outcomes, focusing on youths aged 12 to 17 years. We also examined the influence of policy variables on youth access when these variables were held at 2002 levels. RESULTS Per capita funding for state tobacco control programs was negatively associated with all 4 smoking outcomes. Smoke-free air laws were negatively associated with all outcomes except past-year initiation, and cigarette prices were associated only with current smoking. We found no association between these outcomes and retailer compliance with youth access laws. CONCLUSIONS Smoke-free air laws and state tobacco control programs are effective strategies for curbing youth smoking.

Reasons for current E-cigarette use among U.S. adults

INTRODUCTION Identifying trajectories of cigarette smoking based on usage patterns is important in elucidating the pathway from initiation to nicotine dependence. Various methods have been used to identify different smoking patterns based on either quantity or frequency smoked. METHODS This paper examines the link between smoking exposure and nicotine dependence symptoms while looking at both daily and less-than-daily smokers in a nationally representative sample. RESULTS Our study found a distinct pattern of cigarette smoking among adolescents aged 12-18 years, suggesting a trajectory in which smokers typically progressed through the following steps: smoking less than 1 cigarette on 1-5 days per month; smoking 1-5 cigarettes on 1-5, 6-9, 10-19, 20-29, and 30 days; and then smoking 6-10 cigarettes on 30 days, 11-20 on 30 days, and more than 20 on 30 days. Few smokers deviated from this pattern. A dose-response relationship was observed between this smoking pattern and having any of the four nicotine dependence symptoms and also with the number of reported nicotine dependence symptoms. DISCUSSION The relationship we found between smoking exposure and nicotine dependence symptoms is consistent with the homeostasis-sensitization theory: according to which sensitization involves periods in which a person is increasing the number of cigarettes smoked per day and homeostasis occurs when the number of cigarettes smoked per day remains stable. We provide data that can be used in future studies to update and expand the work on trajectories.