Biochemical Verification of Tobacco Use and Abstinence: 2019 Update.

BACKGROUND: The changing prevalence and patterns of tobacco use, the advent of novel nicotine delivery devices, and the development of new biomarkers prompted an update of the 2002 Society for Research on Nicotine and Tobacco (SRNT) report on whether and how to apply biomarker verification for tobacco use and abstinence. METHODS: The SRNT Treatment Research Network convened a group of investigators with expertise in tobacco biomarkers to update the recommendations of the 2002 SNRT Biochemical Verification Report. RESULTS: Biochemical verification of tobacco use and abstinence increases scientific rigor and is recommended in clinical trials of smoking cessation, when feasible. Sources, appropriate biospecimens, cutpoints, time of detection windows and analytic methods for carbon monoxide, cotinine (including over the counter tests), total nicotine equivalents, minor tobacco alkaloids, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol are reviewed, as well as biochemical approaches to distinguishing cigarette smoking from use of electronic nicotine delivery devices (ENDS). CONCLUSIONS: Recommendations are provided for whether and how to use biochemical verification of tobacco use and abstinence. Guidelines are provided on which biomarkers to use, which biospecimens to use, optimal cutpoints, time windows to detection, and methodology for biochemical verifications. Use of combinations of biomarkers is recommended for assessment of ENDS use. IMPLICATIONS: Biochemical verification increases scientific rigor, but there are drawbacks that need to be assessed to determine whether the benefits of biochemical verification outweigh the costs, including the cost of the assays, the feasibility of sample collection, the ability to draw clear conclusions based on the duration of abstinence, and the variability of the assay within the study population. This paper provides updated recommendations from the 2002 SRNT report on whether and how to use biochemical markers in determining tobacco use and abstinence.

Variation in nicotine intake among U.S. cigarette smokers during the past 25 years: evidence from NHANES surveys.

OBJECTIVE: To estimate changes in nicotine intakes among U.S. cigarette smokers from 1988 to 2012 with the National Health and Nutrition Examination Survey (NHANES). METHODS: NHANES provides data on nationally representative samples of cigarette smokers from the civilian noninstitutionalized U.S. population. A total of 4,304 smokers aged 20 years and older were studied in NHANES III 1988-1994 and 7,095 were studied in the continuous NHANES 1999-2012. We examined serum cotinine concentrations, daily cigarette consumption, and estimated nicotine intake per cigarette, with adjustment for sex, age, racial/ethnic background, level of education, and body mass index. RESULTS: There was little overall change in nicotine intake from smoking cigarettes either in the U.S. population as a whole or in major racial/ethnic subgroups during the 25-year period from 1988. Serum cotinine averaged 223.7ng/mL (95% confidence interval [CI] = 216.1-231.3) in 1988-1994, which was not significantly different from the adjusted mean of 219.2ng/mL (95% CI = 214.1-224.4) in 1999-2012. During the same period, average daily cigarette consumption declined substantially, from 17.3 (95% CI = 16.5-18.0) in 1988-1994 to 12.3 (95% CI = 11.0-13.6) by 2012. Cotinine per cigarette smoked increased by some 42% between 1988-1994 and 2011-2012, from a geometric mean of 12.4 (95% CI = 11.7-13.1) to 17.6 (95% CI = 16.1-19.2). CONCLUSIONS: Reductions in cigarette smoking prevalence since the late 1980s, changes in cigarette product design, and the widespread introduction of smoke-free policies have not had a significant impact on nicotine intakes among U.S. smokers. Reductions in cigarette consumption have been offset by increased nicotine intake per cigarette smoked.

Secondhand Nicotine Absorption From E-Cigarette Vapor vs Tobacco Smoke in Children.

Importance: With the prevalence of e-cigarette use (vaping) increasing worldwide, there are concerns about children's exposure to secondhand vapor. Objective: To compare nicotine absorption among children who are (1) exposed to secondhand tobacco smoke only or (2) exposed to secondhand vapor only with (3) those exposed to neither. Design, Setting, and Participants: The US Continuous National Health and Nutrition Examination Survey (NHANES) is a repeat cross-sectional survey. Participants are interviewed in their homes and, several days after, visit a mobile examination center to provide biological specimens. This study uses data from a nationally representative sample of US households from 2017 to 2020. Participants were children aged 3 to 11 years with serum cotinine levels incompatible with current firsthand nicotine use (ie, <15 µg/L). The final analysis was conducted on January 9, 2024. Exposures: Reported exposure to secondhand smoke or vapor indoors in the past 7 days (only secondhand smoke, only secondhand vapor, or neither). Covariates included age, sex, ethnicity, family income, body weight, and height. Main Outcomes and Measures: The primary outcome was serum cotinine concentration, an objective biomarker of nicotine absorption. Geometric mean cotinine levels and 95% CIs were calculated using log-normal tobit regression, accounting for the complex survey design and weights. Results: The mean (SD) age of the 1777 children surveyed was 7.4 (2.6) years, 882 (49.6%) were female, and 531 (29.9%) had family incomes below the poverty level. Nicotine absorption, as indexed by serum cotinine level, was highest among children only exposed to secondhand smoke (0.494 µg/L µg/L; 95% CI, 0.386-0.633 µg/L), followed by those exposed only to secondhand vapor (0.081 µg/L; 95% CI, 0.048-0.137 µg/L), equating to 83.6% (95% CI, 71.5%-90.5%; P < .001) lower nicotine absorption. Among children with no reported secondhand exposure, the geometric mean cotinine level was 0.016 µg/L (95% CI, 0.013-0.021 µg/L), or 96.7% (95% CI, 95.6%-97.6%; P < .001) lower than for those with exposure to secondhand smoke. Results were similar after covariate adjustment. Conclusions and Relevance: In this cross-sectional study of US children, nicotine absorption was much lower in children who were exposed to secondhand vapor vs secondhand smoke, but higher than in those exposed to neither. These findings suggest that switching from smoking to vaping indoors may substantially reduce, but not eliminate, children's secondhand exposure to nicotine and other noxious substances.

Tobacco use in 3 billion individuals from 16 countries: an analysis of nationally representative cross-sectional household surveys.

BACKGROUND: Despite the high global burden of diseases caused by tobacco, valid and comparable prevalence data for patterns of adult tobacco use and factors influencing use are absent for many low-income and middle-income countries. We assess these patterns through analysis of data from the Global Adult Tobacco Survey (GATS). METHODS: Between Oct 1, 2008, and March 15, 2010, GATS used nationally representative household surveys with comparable methods to obtain relevant information from individuals aged 15 years or older in 14 low-income and middle-income countries (Bangladesh, Brazil, China, Egypt, India, Mexico, Philippines, Poland, Russia, Thailand, Turkey, Ukraine, Uruguay, and Vietnam). We compared weighted point estimates and 95% CIs of tobacco use between these 14 countries and with data from the 2008 UK General Lifestyle Survey and the 2006-07 US Tobacco Use Supplement to the Current Population Survey. All these surveys had cross-sectional study designs. FINDINGS: In countries participating in GATS, 48·6% (95% CI 47·6-49·6) of men and 11·3% (10·7-12·0) of women were tobacco users. 40·7% of men (ranging from 21·6% in Brazil to 60·2% in Russia) and 5·0% of women (0·5% in Egypt to 24·4% in Poland) in GATS countries smoked a tobacco product. Manufactured cigarettes were favoured by most smokers (82%) overall, but smokeless tobacco and bidis were commonly used in India and Bangladesh. For individuals who had ever smoked daily, women aged 55-64 years at the time of the survey began smoking at an older age than did equivalently aged men in most GATS countries. However, those individuals who had ever smoked daily and were aged 25-34-years when surveyed started to do so at much the same age in both sexes. Quit ratios were very low (<20% overall) in China, India, Russia, Egypt, and Bangladesh. INTERPRETATION: The first wave of GATS showed high rates of smoking in men, early initiation of smoking in women, and low quit ratios, reinforcing the view that efforts to prevent initiation and promote cessation of tobacco use are needed to reduce associated morbidity and mortality. FUNDING: Bloomberg Philanthropies' Initiative to Reduce Tobacco Use, Bill and Melinda Gates Foundation, Brazilian and Indian Governments.

Dispelling myths about gender differences in smoking cessation: population data from the USA, Canada and Britain.

OBJECTIVES: Based mainly on findings from clinical settings, it has been claimed that women are less likely than men to quit smoking successfully. If true, this would have important implications for tobacco control interventions. The authors aimed to test this possibility using data from general population surveys. METHODS: The authors used data from major national surveys conducted in 2006-2007 in the USA (Tobacco Use Supplement to the Current Population Survey), Canada (Canadian Tobacco Use Monitoring Survey) and the UK (General Household Survey) to estimate rates of smoking cessation by age in men and women. RESULTS: The authors found a pattern of gender differences in smoking cessation which was consistent across countries. Below age 50, women were more likely to have given up smoking completely than men, while among older age groups, men were more likely to have quit than women. Across all age groups, there was relatively little difference in cessation between the sexes. CONCLUSIONS: Conclusions about gender differences in smoking cessation should be based on evidence from the general population rather than from atypical clinical samples. This study has found convincing evidence that men in general are not more likely to quit smoking successfully than women.

Impact of smoke-free legislation on children's exposure to secondhand smoke: cotinine data from the Health Survey for England.

OBJECTIVE: To examine the impact of the ban on smoking in enclosed public places implemented in England in July 2007 on children's exposure to secondhand tobacco smoke. DESIGN: Repeated cross-sectional surveys of the general population in England. SETTING: The Health Survey for England. PARTICIPANTS: Confirmed non-smoking children aged 4-15 with measured saliva cotinine participating in surveys from 1998 to 2008, a total of 10,825 children across years. MAIN OUTCOME MEASURES: The proportion of children living in homes reported to be smoke-free; the proportion of children with undetectable concentrations of cotinine; geometric mean cotinine as an objective indicator of overall exposure. RESULTS: Significantly more children with smoking parents lived in smoke-free homes in 2008 (48.1%, 95% CI 43.0% to 53.1%) than in either 2006 (35.5%, 95% CI 29.7% to 41.7%) or the first 6 months of 2007, immediately before the ban came into effect (30.5%, 95% CI 19.7% to 43.9%). A total of 41.1% (95% CI 38.9% to 43.4%) of children had undetectable cotinine in 2008, up from 34.0% (95% CI 30.8% to 37.3%) in 2006. Geometric mean cotinine in all children combined was 0.21 ng/ml (95% CI 0.20 to 0.23) in 2008, slightly lower than in 2006, 0.24 ng/ml (95% CI 0.21 to 0.26). CONCLUSIONS: Predictions that the 2007 legislative ban on smoking in enclosed public places would adversely affect children's exposure to tobacco smoke were not confirmed. While overall exposure in children has not been greatly affected by the ban, the trend towards the adoption of smoke-free homes by parents who themselves smoke has received fresh impetus.

Children's exposure to second-hand smoke 10 years on from smoke-free legislation in England: Cotinine data from the Health Survey for England 1998-2018.

BACKGROUND: We aimed to investigate trends in children's exposure to second-hand tobacco smoke in England from 1998 to 2018. METHODS: We used twenty-one years of data from the Health Survey for England, a yearly repeated cross-sectional population study. A total of 49,460 children participated between 1998 and 2018, of whom 17,463 were biochemically confirmed non-smokers aged 4-15. We examined changes in (i) the proportion of children living in reported smoke-free homes and (ii) second-hand smoke uptake, measured quantitatively using saliva cotinine concentration. FINDINGS: The percentage of children living in a home reported to be smoke-free increased from 63.0% (95% CI 60.5%-65.2%) in 1998 to 93.3% (91.8%-94.6%) in 2018. This increase was most pronounced among children with a smoker parent, rising from 17.1% (14.7%-19.8%) to 75.9% (70.8%-80.4%). Segmented regression showed that the rate of adoption of smoke-free homes accelerated leading up to the 2007 ban on smoking in public places, growing most rapidly in the four years after its entry into law. Between 1998 and 2018, there was a ten-fold decline in geometric mean cotinine among non-smoking children, from 0.50 ng/ml (0.46-0.56) to 0.05 ng/ml (0.04-0.06). A total of 65.0% (61.2%-68.6%) of children had undetectable cotinine in 2018, up from 14.3% (12.7%-16.0%) in 1998. Children living in rented accommodation were more exposed than those from owner-occupied households, but they experienced similar relative declines across years. INTERPRETATION: Cotinine data show that children's exposure to second-hand smoke has fallen by some 90% since 1998, with an apparent acceleration in adoption of smoke-free homes since the 2007 ban on smoking in public places. A norm has emerged that sees smoking in the home as inappropriate, almost universally where parents are non-smokers, but also increasingly among smoking parents. FUNDING: Public Health England, now the Office for Health Improvement and Disparities, and Cancer Research UK.

'The smoking toolkit study': a national study of smoking and smoking cessation in England.

BACKGROUND: Up-to-date data tracking of national smoking patterns and cessation-related behaviour is required to evaluate and inform tobacco control strategies. The Smoking Toolkit Study (STS) was designed for this role. This paper describes the methodology of the STS and examines as far as possible the representativeness of the samples. METHODS: The STS consists of monthly, cross sectional household interviews of adults aged 16 and over in England with smokers and recent ex-smokers in each monthly wave followed up by postal questionnaires three and six months later. Between November 2006 and December 2010 the baseline survey was completed by 90,568 participants. STS demographic, prevalence and cigarette consumption estimates are compared with those from the Health Survey for England (HSE) and the General Lifestyle Survey (GLF) for 2007-2009. RESULTS: Smoking prevalence estimates of all the surveys were similar from 2008 onwards (e.g 2008 STS=22.0%, 95% C.I.=21.4% to 22.6%, HSE=21.7%, 95% C.I.=20.9% to 22.6%, GLF=20.8%, 95% C.I.=19.7% to 21.9%), although there was heterogeneity in 2007 (chi-square=50.30, p<0.001). Some differences were observed across surveys within sociodemographic sub-groups, although largely in 2007. Cigarette consumption was virtually identical in all surveys and years. CONCLUSION: There is reason to believe that the STS findings (see http://www.smokinginengland.info) are generalisable to the adult population of England.

Dependence on nicotine in US high school students in the context of changing patterns of tobacco product use.

BACKGROUND AND AIM: There have been substantial recent changes in youth tobacco product use in the United States-including, notably, a rapid increase in use of e-cigarettes. It is not known whether, and if so how far, these changes are reflected in levels of nicotine dependence. This study used data from a large, nationally representative sample of US adolescents to (i) estimate the annual prevalence of nicotine dependence in relation to current use of tobacco products, (ii) describe trends in dependence over time and (iii) evaluate whether the increase in youth use of tobacco products has been paralleled by a similar increase in the population burden of nicotine dependence. DESIGN: Secondary analysis of National Youth Tobacco Surveys conducted annually, 2012-19. SETTING: United States. PARTICIPANTS: A total of 86 902 high school students. MEASUREMENTS: Prevalence of (i) strong cravings to use tobacco in the past 30 days and (ii) wanting to use nicotine products within 30 minutes of waking, in relation to type of product used (cigarettes, other combustible tobacco, smokeless tobacco, e-cigarettes). FINDINGS: Between 2012 and 2019 there was a marked decline in past 30-day cigarette smoking and a surge in use of e-cigarettes. Different products were associated with differing levels of nicotine dependence, with cigarettes characterized by highest dependence (strong craving 42.3%; wanting to use within 30 minutes 16.8% among exclusive users in 2019) and e-cigarettes in otherwise tobacco-naive students by low dependence (16.1 and 8.8% respectively in 2019). The overall 33.8% increase in population use of nicotine products between 2012 and 2019 (from 23.2 to 31.2%) was not accompanied by an equivalent increase in overall population burden of dependence {percentage reporting craving 10.9% [95% confidence interval (CI) = 9.8-12.2%] in 2012 and 9.5% (95% CI = 7.5-12.0%) in 2019; wanting to use within 30 minutes 4.7% (95% CI = 4.0-5.5%) in 2012, 5.4% (95% CI = 4.0-7.2%) in 2019}. CONCLUSIONS: Among US high school students, increases in the prevalence of nicotine product use from 2012 to 2019 do not appear to have been accompanied by a similar increase in the population burden of nicotine dependence. This may be at least partly attributable to a shift in the most common product of choice from cigarettes (on which users are most dependent) to e-cigarettes (on which users are least dependent).

England SimSmoke: the impact of nicotine vaping on smoking prevalence and smoking-attributable deaths in England.

BACKGROUND AND AIMS: Whereas the use of nicotine vaping products (NVPs) is widespread, their impact on smoking prevalence is controversial. This study considered the potential impact of NVPs on smoking prevalence in England. DESIGN: Indirect simulation model. The England SimSmoke model is validated through 2012, before NVP use became more widely used by smokers. Because information on NVP-related transitions is limited, an indirect method is used; the difference in observed smoking prevalence (reflecting NVPs) is compared with a 2012-2019 counterfactual No-NVP scenario (without NVPs) to estimate the impact of NVPs on smoking and smoking-attributable deaths. SETTING: England, 2000-2019. PARTICIPANTS: Nationally representative sample of population. MEASUREMENTS: England's population, mortality rates and smoking prevalence estimates from three national surveys and tobacco control policies. FINDINGS: Between 2000 and 2012, SimSmoke projected a decline in age 18+ smoking prevalence of 23.5% in men and 27.0% in women. These projections, as well as those by specific age groups, were generally consistent with findings from the three national surveys. Comparing 2012-2019 relative reduction in age 18+ prevalence from the Annual Population Survey (males, 27.5%) with the model-predicted No-NVP reduction (males, 7.3%), the implied NVP-attributable relative reduction in adult smoking prevalence was 20.2% (95% CI, 18.8%-22.0%) for males and 20.4% (18.7%-22.2%) for females. The NVP-attributable reduction was 27.2% (22.8%-31.6%) for males and 31.7% (27.4%-36.5%) for females ages 18-24 and 18.6% (15.2%-21.8%) for males and 15.0% (11.1%-18.8%) for females ages 25-34, with similar reductions for ages 35+. The implied reduction in smoking prevalence between 2012 and 2019 equates to 165 660 (132 453-199 501) averted deaths by 2052. Other surveys yielded smaller, but relatively consistent results. CONCLUSIONS: An indirect method of simulation modelling indicates that substantial reductions in smoking prevalence occurred in England from 2012-2019 coinciding with the growth in nicotine vaping product use.

Awareness of lifestyle risk factors for cancer and heart disease among adults in the UK.

OBJECTIVE: To examine and compare awareness of lifestyle risk factors for cancer and heart disease in a single UK representative sample. METHODS: Two open-ended questions about cancer and heart disease risk factors were included in a population-based survey of 1747 adults. Responses were coded for four lifestyles with established links to both diseases: smoking, eating an unhealthy diet, drinking excessive alcohol and physical inactivity. RESULTS: Awareness of lifestyle risk factors was low for both diseases, although higher for heart disease than cancer. The average number identified by respondents was 2.1 (heart disease) and 1.4 (cancer). The strongest predictor was education (both p<0.001). Awareness that physical inactivity is a cancer risk factor was particularly low at 7%. CONCLUSION: These findings suggest that public awareness of the impact of lifestyle on commonly feared diseases, especially cancer, is low. PRACTICE IMPLICATIONS: Unhealthy lifestyles make a significant contribution to ill health and mortality. Increased public awareness of the links between lifestyles and commonly feared diseases might help people understand the potential health consequences of their actions and encourage them to make much-needed lifestyle changes. Efforts are needed to improve public health messages about how lifestyle risk factors impact on the chances of developing these important diseases.

The place for harm reduction and product regulation in UK tobacco control policy.

Tobacco use remains the leading cause of preventable death in this country and more needs to be done to reduce smoking rates. Harm reduction is one policy option. Smokers smoke for the nicotine, but die from the other toxins in cigarette smoke. Harm reduction in tobacco control aims to reduce the harm arising from nicotine use by shifting smokers, who are unable to quit, to using far less hazardous sources of nicotine, notably medicinal nicotine, in place of cigarettes. This article argues that for harm reduction to work in the UK, a nicotine product regulation authority is first needed. This would regulate nicotine products in proportion to harm to ensure that, contrary to the current paradoxical arrangements, the most harmful source of nicotine, the cigarette, becomes the most highly regulated (and thus the least easily accessible, available and attractive). It goes onto explore how a harm reduction strategy might be further developed, exploring controversies and potential pitfalls. It argues that the public health community needs to own and drive this debate because failure to do so would let the tobacco industry gain the upper hand and see thousands of more unnecessary deaths from tobacco use.

Nicotine intake in cigarette smokers in England: distribution and demographic correlates.

Documenting smoke intake by objective biochemical markers is important for quantification of exposure to toxins. The aim of this report is to show the most definitive distribution of the nicotine metabolite, cotinine, yet available from English smokers in the period before implementation of the legislation banning smoking in indoor public areas. A total of 6,423 cigarette smokers, ages 16 years and above, taking part in the Health Survey for England between 1998 and 2003 provided a saliva cotinine value. Data on cigarette consumption, age, gender, social class, deprivation (as indicated by manual or nonmanual occupation, car ownership, and housing tenure), marital status, and region were collected. Cotinine concentrations showed no overall trend over the study period. The mean value was 289.15 ng/mL (SD 174.43); excluding those who had not smoked in the past 24 hours, the mean value was 302.08 ng/mL (SD 168.78). A higher cotinine concentration was associated with being middle-aged (peaking at 40 years), being male, being single, greater economic deprivation, and not living in London. After adjusting for cigarette consumption, higher values were associated with middle age, being male, and greater deprivation. This study provides the most complete picture yet of the smoke intake of cigarette smokers in England. The fact that cotinine peaks at around the age of 40 years raises the possibility that nicotine intake continues to increase decades after a person starts to smoke. Greater nicotine intake in more deprived smokers could explain why they find it harder to stop smoking.

Assessing smoking status in children, adolescents and adults: cotinine cut-points revisited.

AIMS: To reassess saliva cotinine cut-points to discriminate smoking status. Cotinine cut-points that are in use were derived from relatively small samples of smokers and non-smokers 20 or more years ago. It is possible that optimal cut-points may have changed as prevalence and exposure to passive smoking have declined. DESIGN: Cross-sectional survey of the general population, with assessment of self-reported smoking and saliva cotinine. PARTICIPANTS: A total of 58 791 respondents aged 4 years and older in the Health Survey for England for the years 1996-2004 who provided valid saliva cotinine specimens. MEASURES: Saliva cotinine concentrations, demographic variables, self-reported smoking, presence or absence of smoking in the home, a composite index of social disadvantage derived from occupation, housing tenure and access to a car. FINDINGS: A cut-point of 12 ng/ml performed best overall, with specificity of 96.9% and sensitivity of 96.7% in discriminating confirmed cigarette smokers from never regular smokers. This cut-point also identified correctly 95.8% of children aged 8-15 years smoking six or more cigarettes a week. There was evidence of substantial misreport in claimed ex-smokers, especially adolescents (specificity 72.3%) and young adults aged 16-24 years (77.5%). Optimal cut-points varied by presence (18 ng/ml) or absence (5 ng/ml) of smoking in the home, and there was a gradient from 8 ng/ml to 18 ng/ml with increasing social disadvantage. CONCLUSIONS: The extent of non-smokers' exposure to other people's tobacco smoke is the principal factor driving optimal cotinine cut-points. A cut-point of 12 ng/ml can be recommended for general use across the whole age range, although different cut-points may be appropriate for population subgroups and in societies with differing levels of exposure to secondhand smoke.

Smoking status of step-parents as a risk factor for smoking in adolescence.

AIM: To examine the extent to which smoking by step-parents and biological parents predicts adolescent smoking. DESIGN Five-year cohort study. SETTING Thirty-six schools in South London, England. Participants A subset of 650 students participating in the Health and Behaviour In Teenagers Study (HABITS), who reported living in step-families, were assessed annually from age 11-12 to age 15-16 years. MEASUREMENTS: Students reported their smoking status, which was cotinine-verified, as well as whether their parents smoked and, if they lived with a step-parent, whether that step-parent smoked. Analyses also controlled for gender, ethnicity and deprivation. FINDINGS: Students who reported that just their step-parent smoked at age 11-12 were significantly more likely to report current smoking at any time-point from age 11-16 than those who reported having neither biological parents nor a step-parent who smoked [odds ratio (OR) 2.72, 95% confidence interval (CI) = 1.36-5.47], as were those with both a parent and a step-parent who smoked (OR 2.23, 95% CI = 1.46-3.41). While the association between smoking in students and smoking in biological parents in this subsample did not reach statistical significance (OR 1.39, 95% CI = 0.88-2.19), these students were no more or less likely to smoke than those with just a step-parent who smoked. CONCLUSION: Smoking by a non-biological parent appears at least as influential as smoking by biological parents. This confirms the importance of social influence on smoking initiation and suggests that attempts to work with parents in smoking prevention should involve, and perhaps pay particular attention to, step-parents who smoke.

Psychological and behavioural impact of genetic testing smokers for lung cancer risk: a phase II exploratory trial.

The behavioural and psychological impact of genetic testing for lung cancer susceptibility was examined among smokers (N = 61) who were randomly allocated to a GSTM1 genetic testing group (with GSTM1-missing or GSTM1-present result) or no-test control group. The GSTM1-missing (higher risk) group reported greater motivation to quit smoking, and both genetic testing groups reported lower depression than the control group at one-week follow-up (p < .05 for all). Differences were not significant at two months follow-up. This study indicates the feasibility of much-needed research into the risks and benefits for individuals of emerging lifestyle-related genetic susceptibility tests.

Can we trust national smoking prevalence figures? Discrepancies between biochemically assessed and self-reported smoking rates in three countries.

BACKGROUND: National smoking prevalence estimates are the primary basis for assessing progress in tobacco control across the world. They are based on surveys of self-reported cigarette smoking. It has been assumed that this is sufficiently accurate for policy purposes, but this assumption has not been adequately tested. METHODS: We report data from the 2003 Health Survey for England, the U.S. National Health and Nutrition Examination Survey for 2001-2002, and the 2004 national smoking behaviors survey in Poland as examples of countries at different stages in the "tobacco epidemic." Self-reported cigarette and total tobacco smoking prevalence were assessed by means of the standard questions used in each country. In subsamples, specimens were collected for analysis of cotinine (saliva, N = 1,613 in England; serum, N = 4,687 in the United States; and saliva, N = 388 in Poland) providing an objective means of determining active smoking. A cut point of 15 ng/mL was used to discriminate active smoking from passive smoke exposure. RESULTS: Self-reported cigarette smoking prevalence using the standard methods underestimated true tobacco smoking prevalence by an estimated 2.8% in England, 0.6% in the United States, and 4.4% in Poland. Cotinine concentrations in those misclassified as nonsmokers were indicative of high levels of smoke intake. INTERPRETATION: Underestimation of smoking prevalence was minimal in the United States but significant in England and Poland. A review of methodologies for assessing tobacco smoking prevalence worldwide is urgently needed.

Social inequalities in male mortality, and in male mortality from smoking: indirect estimation from national death rates in England and Wales, Poland, and North America.

BACKGROUND: There are substantial social inequalities in adult male mortality in many countries. Smoking is often more prevalent among men of lower social class, education, or income. The contribution of smoking to these social inequalities in mortality remains uncertain. METHODS: The contribution of smoking to adult mortality in a population can be estimated indirectly from disease-specific death rates in that population (using absolute lung cancer rates to indicate proportions due to smoking of mortality from certain other diseases). We applied these methods to 1996 death rates at ages 35-69 years in men in three different social strata in four countries, based on a total of 0.6 million deaths. The highest and lowest social strata were based on social class (professional vs unskilled manual) in England and Wales, neighbourhood income (top vs bottom quintile) in urban Canada, and completed years of education (more than vs less than 12 years) in the USA and Poland. RESULTS: In each country, there was about a two-fold difference between the highest and the lowest social strata in overall risks of dying among men aged 35-69 years (England and Wales 21%vs 43%, USA 20%vs 37%, Canada 21%vs 34%, Poland 26%vs 50%: four-country mean 22%vs 41%, four-country mean absolute difference 19%). More than half of this difference in mortality between the top and bottom social strata involved differences in risks of being killed at age 35-69 years by smoking (England and Wales 4%vs 19%, USA 4%vs 15%, Canada 6%vs 13%, Poland 5%vs 22%: four-country mean 5%vs 17%, four-country mean absolute difference 12%). Smoking-attributed mortality accounted for nearly half of total male mortality in the lowest social stratum of each country. CONCLUSION: In these populations, most, but not all, of the substantial social inequalities in adult male mortality during the 1990s were due to the effects of smoking. Widespread cessation of smoking could eventually halve the absolute differences between these social strata in the risk of premature death.

Does smoking in adolescence affect body mass index, waist or height? Findings from a longitudinal study.

AIM: To assess the effect of smoking uptake on body mass index (BMI), waist circumference and height during adolescence. DESIGN: Five-year longitudinal study. SETTING: Thirty-six schools in South London, England, selected by a stratified random sampling procedure designed to ensure ethnic and socio-economic diversity. PARTICIPANTS: A total of 5863 students took part in the HABITS (Health and Behaviour in Teenagers) Study between 1999 and 2003. MEASUREMENTS: Self-reported smoking behaviour, saliva cotinine concentrations and measured weight, waist circumference and height were obtained, along with information on gender, ethnicity, socio-economic deprivation, pubertal status, self-reported exercise and dieting. Students were examined annually from school year 7 (ages 11-12) to year 11 (ages 15-16), with response rates ranging from 74 to 84%. A total of 2665 never smokers at year 7 with complete data for years 7 and 11 were included in the analyses. FINDINGS: Adjusting for year 7 BMI and other potential confounders, regular smokers (more than six cigarettes a week) at year 11 had significantly lower BMI (P = 0.002) than other students. Smokers defined by a cotinine above 15 ng/ml also had lower BMI (P < 0.0001). Waist circumferences were lower in regular smokers (P = 0.014) and cotinine-defined smokers (P < 0.011). No consistent association was found between smoking and height. The adjusted difference in weight between regular smokers and other students amounted to 1.8 kg (95% CI, 0.52-3.17) for an average-height student. CONCLUSION: Taking up regular smoking during adolescence may result in a lower BMI, but the effect is small and of uncertain significance.

UK smokers' and ex-smokers' reactions to cigarettes promising reduced risk.

AIMS: This study evaluated the impact of exposure to information about a novel cigarette claiming to reduce exposure to tobacco toxins ('potential reduced exposure product' cigarette or PREP-C) on smokers' and ex-smokers' perceptions of PREP-C, on quit interest among smokers and on interest in resuming smoking among ex-smokers. DESIGN AND PARTICIPANTS: A random digit-dialed telephone survey was conducted in the United Kingdom with 500 current smokers and 106 ex-smokers who had quit within the last 2 years. INTERVENTION: The interviewer described a novel cigarette that claimed to significantly reduce exposure to smoke toxins. MEASUREMENTS: Respondents' interest in purchasing the PREP-C, beliefs about its safety and risk reduction and smokers' quit interest, as measured by stage of change, before and after exposure to PREP-C information. FINDINGS: Among smokers, 76.5% were interested in purchasing PREP-C; interest did not vary by stage of change. Almost all smokers (90.6%) thought PREP-C was safer than regular cigarettes, with 5.4% indicating that the health risks were equivalent to not smoking at all. Exposure to PREP-C description did not change quit interest. Among ex-smokers, 5.6% believed PREP-C carried no health risk and 7.1% expressed purchase interest. CONCLUSIONS: Smokers and ex-smokers interpreted claims of reduced toxin exposure as reduced health risk and responded positively towards PREP-Cs. With the increasing introduction of PREP-Cs world-wide, evaluation of these products and their claims on quitting among smokers and on relapse among ex-smokers is a matter of public health urgency.