Should the health community promote smokeless tobacco (snus) as a harm reduction measure?

Smokeless tobacco use in Australia

INTRODUCTION AND AIMS

There has been little research published on the use of smokeless tobacco (SLT) in Australia. This study aimed to determine the prevalence of SLT use and the potential for harm reduction in current SLT users and smokers.

DESIGN AND METHODS

We undertook secondary analysis of data from a national household survey of drug use and surveyed 108 Australian SLT users about their patterns of SLT use and tobacco smoking.

RESULTS

The low prevalence of SLT use in the past year in Australia (0.57%; 95% confidence interval 0.48–0.66) might reflect the difficulty in importing these products. Prevalence of recent use was highest among males aged 18–29 who were current weekly smokers. US style oral snuffs were the most popular SLT products in Australia. Most of those surveyed were introduced to SLT by a personal contact and about half had used SLT to quit smoking. Australians who import SLT pay per can AU$21.30 on average and face substantial delays before receiving the product.

DISCUSSION AND CONCLUSIONS

Cost and poor access present a substantial barrier to SLT use as a tobacco harm reduction measure for Australian smokers. Permitting low nitrosamine varieties of SLT to be sold in Australia might reduce harm in current SLT users and provide a viable alternative to cigarettes for some current smokers.

Tracking the rise in popularity of electronic nicotine delivery systems (electronic cigarettes) using search query surveillance

BACKGROUND

Public interest in electronic nicotine delivery systems (ENDS) is undocumented.

PURPOSE

By monitoring search queries, ENDS popularity and correlates of their popularity were assessed in Australia, Canada, the United Kingdom (UK), and the U.S.

METHODS

English-language Google searches conducted from January 2008 through September 2010 were compared to snus, nicotine replacement therapy (NRT), and Chantix® or Champix®. Searches for each week were scaled to the highest weekly search proportion (100), with lower values indicating the relative search proportion compared to the highest-proportion week (e.g., 50=50% of the highest observed proportion). Analyses were performed in 2010.

RESULTS

From July 2008 through February 2010, ENDS searches increased in all nations studied except Australia, there an increase occurred more recently. By September 2010, ENDS searches were several-hundred-fold greater than searches for smoking alternatives in the UK and U.S., and were rivaling alternatives in Australia and Canada. Across nations, ENDS searches were highest in the U.S., followed by similar search intensity in Canada and the UK, with Australia having the fewest ENDS searches. Stronger tobacco control, created by clean indoor air laws, cigarette taxes, and anti-smoking populations, were associated with consistently higher levels of ENDS searches.

CONCLUSIONS

The online popularity of ENDS has surpassed that of snus and NRTs, which have been on the market for far longer, and is quickly outpacing Chantix or Champix. In part, the association between ENDS's popularity and stronger tobacco control suggests ENDS are used to bypass, or quit in response to, smoking restrictions. Search query surveillance is a valuable, real-time, free, and public method to evaluate the diffusion of new health products. This method may be generalized to other behavioral, biological, informational, or psychological outcomes manifested on search engines.

Forecasting future tobacco control policy: where to next?

OBJECTIVE

Effective tobacco control policies include price increases through taxes, restrictions on smoking in public and work places, adequately funded mass media campaigns, bans on advertising, health warnings on packages and cessation assistance. As these policies have been largely implemented in Australia, what next should the country do in tobacco control?

METHODS

Ninety-one Australian tobacco control stakeholders took part in a web-based survey about the future of tobacco control policies.

RESULTS

The policy deemed most important in decreasing smoking was to increase excise and customs duty by 30%. Other policies receiving high support included: funding mass media campaigns through tax hypothecation; introducing retail display bans; plain packaging of tobacco products; and banning smoking in outdoor dining areas. Reintroducing the sale of smokeless tobacco products received the least support.

CONCLUSION

Countries that have largely implemented the provisions of the Framework Convention on Tobacco Control must maintain commitments to proven tobacco control measures, but also provide global leadership through the adoption of innovative policies.

IMPLICATIONS

The release of the Australian 2009 National Preventative Health Taskforce's report presents an opportunity to translate these ideas into action.

Preventing Relapse Following Smoking Cessation

Cigarette smoking is the leading cause of preventable deaths worldwide. Long-term smoking cessation can drastically reduce people's risk for developing smoking-related disease. The research literature points to a need for clearer operationalization and differentiation between smoking cessation and relapse prevention interventions and outcomes. That said, extensive meta-analyses and research studies have indicated that there are various efficacious smoking interventions that can both support smoking cessation and relapse prevention efforts. Specifically, behavioral treatments, relapse prevention psychotherapy, pharmacologic interventions, motivational enhancement, smoking reduction to quit, brief advice, alternative intervention modes (telephone, Internet, computer), self-help, and tailored treatments can help prepare smokers for longer-term abstinence. Although these methods vary on reach, they are relatively efficacious, particularly in combined formats.

Does dual use jeopardize the potential role of smokeless tobacco in harm reduction?

INTRODUCTION

The use of smokeless tobacco as part of a strategy to reduce the harm from cigarette smoking is a topic of debate within the tobacco control and public health communities. One concern voiced regarding endorsement of such a tactic is the possibility of actually increasing harm should current smokers adopt dual cigarette/smokeless tobacco use (dual use), which could lead to unintended consequences by perpetuating cigarette smoking, diminishing tobacco cessation, or increasing tobacco-related harm.

METHODS

Here, we review the available literature on health effects and trajectories of use among dual users from a variety of U.S. and European epidemiological studies.

RESULTS

These data suggest that there are not any unique health risks associated with dual use of smokeless tobacco products and cigarettes, which are not anticipated or observed from cigarette smoking alone. Furthermore, studies show that dual users smoke fewer cigarettes than exclusive smokers, and studies of tobacco use patterns over time (tobacco use trajectory data) indicate that dual users are more likely than exclusive cigarette smokers to cease smoking.

CONCLUSIONS

Overall, the concern about dual use appears to be contradicted by the evidence in the literature that dual use of smokeless tobacco and cigarettes may result in reduction in smoking-related harm as smoking intensity is decreased and smoking cessation increases.

Retailers' knowledge of tobacco harm reduction following the introduction of a new brand of smokeless tobacco

BACKGROUND

Tobacco retailers are potential public health partners for tobacco harm reduction (THR). THR is the substitution of highly reduced-risk nicotine products, such as smokeless tobacco (ST) or pharmaceutical nicotine, for cigarettes. The introduction of a Swedish-style ST product, du Maurier snus (dMS) (Imperial Tobacco Canada Limited), which was marketed as a THR product, provided a unique opportunity to assess retailers' knowledge. This study examined retailers' knowledge of THR and compliance with recommendations regarding tobacco sales to young adults.

METHODS

Male researchers, who may have looked younger than 18 years old, visited 60 stores in Edmonton that sold dMS. The researchers asked the retailers questions about dMS and its health risks relative to those from other tobacco products. They also attempted to purchase dMS to ascertain whether retailers would ask for identification to verify that they were at least 18 years old.

RESULTS

Overall, the retailers were only moderately knowledgeable about THR and the differences between dMS and other tobacco products. About half of the retailers correctly indicated that snus is safer than cigarettes; half of whom knew it is safer because it is smoke-free. Fifty percent incorrectly believed that snus causes oral cancer. Less than fifty percent indicated that dMS differs from chewing tobacco because it is in pouches and is used without spitting or chewing (making it more promising for THR). Most (90%) of the retailers asked the researchers for identification when selling dMS.

CONCLUSION

Tobacco retailers are potentially important sources of information about THR, particularly since there are restrictions on the promotion of all tobacco products (regardless of the actual health risks) in Canada. This study found that many retailers in Edmonton do not know the relative health risks of different tobacco products and are therefore unable to pass on accurate information to smokers.

Further considerations on the evaluation of potential reduced-risk tobacco products. Part II: Re-assessment of a heuristic using the CPS-II database

In a previous analysis (see Part I) we proposed a heuristic for assessing the efficacy of potential reduced-risk tobacco products (PRRPs) on lung cancer (LC) rates, using smoking cessation data published in a report from the Iowa Women's Health Study (IWHS) as a basis for sample size estimates. In this study, an additional analysis was performed using cessation data from the much larger Cancer Prevention Study II (CPS-II), which also provides data on different durations of cessation. Statistical methods were used to assess whether smokers switching to a PRRP would reduce their risk of LC. Furthermore, non-inferiority tests compared the LC risk in switchers to that in smokers who had quit smoking. The present work shows that similar sample size estimates were obtained whether the analysis was based on the IWHS or the CPS-II data sets, suggesting that the heuristic may be generally applicable to prospective real-life studies to evaluate PRRPs. Non-inferiority testing of switchers compared with quitters required approximately 10-fold more subjects than did superiority testing of switchers compared with smokers. Altogether, these estimates indicate that it is feasible, in terms of study duration and sample size, to clinically assess the LC risk-reducing potential of a PRRP.

Hypotheses and fundamental study design characteristics for evaluating potential reduced-risk tobacco products. Part I: Heuristic

The risk-reducing effect of a potential reduced-risk tobacco product (PRRP) can be investigated conceptually in a long-term, prospective study of disease risks among cigarette smokers who switch to a PRRP and in appropriate comparison groups. Our objective was to provide guidance for establishing the fundamental design characteristics of a study intended to (1) determine if switching to a PRRP reduces the risk of lung cancer (LC) compared with continued cigarette smoking, and (2) compare, using a non-inferiority approach, the reduction in LC risk among smokers who switched to a PRRP to the reduction in risk among smokers who quit smoking entirely. Using standard statistical methods applied to published data on LC incidence after smoking cessation, we show that the sample size and duration required for a study designed to evaluate the potential for LC risk reduction for an already marketed PRRP, compared with continued smoking, varies depending on the LC risk-reducing effectiveness of the PRRP, from a 5-year study with 8000-30,000 subjects to a 15-year study with <5000 to 10,000 subjects. To assess non-inferiority to quitting, the required sample size tends to be about 10 times greater, again depending on the effectiveness of the PRRP.

Evaluation of in vitro assays for assessing the toxicity of cigarette smoke and smokeless tobacco

BACKGROUND

In vitro toxicology studies of tobacco and tobacco smoke have been used to understand why tobacco use causes cancer and to assess the toxicologic impact of tobacco product design changes. The need for toxicology studies has been heightened given the Food and Drug Administration's newly granted authority over tobacco products for mandating tobacco product performance standards and evaluate manufacturers' health claims about modified tobacco products. The goal of this review is to critically evaluate in vitro toxicology methods related to cancer for assessing tobacco products and to identify related research gaps.

METHODS

PubMed database searches were used to identify tobacco-related in vitro toxicology studies published since 1980. Articles published before 1980 with high relevance also were identified. The data were compiled to examine (a) the goals of the study, (b) the methods for collecting test substances, (c) experimental designs, (d) toxicologic end points, and (e) relevance to cancer risk.

RESULTS

A variety of in vitro assays are available to assess tobacco smoke that address different modes of action, mostly using non-human cell models. However, smokeless tobacco products perform poorly in these assays. Although reliable as a screening tool for qualitative assessments, the available in vitro assays have been poorly validated for quantitative comparisons of different tobacco products. Assay batteries have not been developed, although they exist for nontobacco assessments. Extrapolating data from in vitro studies to human risks remains hypothetical.

CONCLUSIONS

In vitro toxicology methods are useful for screening toxicity, but better methods are needed for today's context of regulation and evaluation of health claims.

Reconciling human smoking behavior and machine smoking patterns: implications for understanding smoking behavior and the impact on laboratory studies

BACKGROUND

Recent Food and Drug Administration legislation enables the mandating of product performance standards for cigarette smoke and the evaluation of manufacturers' health claims for modified tobacco products. Laboratory studies used for these evaluations and also for understanding tobacco smoke toxicology use machines to generate smoke. The goal of this review is to critically evaluate methods to assess human smoking behavior and replicate this in the laboratory.

METHODS

Smoking behavior and smoking machine studies were identified using PubMed and publicly available databases for internal tobacco company documents.

RESULTS

The smoking machine was developed to generate smoke to allow for comparing cigarette tar and nicotine yields. The intent was to infer relative human disease risk, but this concept was flawed because humans tailor their smoking to the product, and chemical yields and toxicologic effects change with different smoking profiles. Although smoking machines also allow for mechanistic assessments of smoking-related diseases, the interpretations also are limited. However, available methods to assess how humans puff could be used to provide better laboratory assessments, but these need to be validated. Separately, the contribution of smoke mouth-holding and inhalation to dose need to be assessed, because these parts of smoking are not captured by the smoking machine. Better comparisons of cigarettes might be done by tailoring human puff profiles to the product based on human studies and comparing results across regimens.

CONCLUSIONS

There are major research gaps that limit the use of smoking machine studies for informing tobacco control regulation and mechanistic studies.

Review of epidemiologic data on the debate over smokeless tobacco's role in harm reduction

Some tobacco researchers have argued that the European Union should remove its ban on a form of low-nitrosamine smokeless tobacco referred to as Swedish 'snus'. This argument has developed in to an international debate over the use of smokeless tobacco as a measure of harm reduction for smokers. Leading authorities in the USA have firmly stated that there is no safe tobacco - a message which does not allow for any discussion of comparative tobacco risks. This commentary is intended to review the origin of the controversy over Swedish 'snus', to examine briefly the meta-analysis on cancer risks by Peter Lee and Jan Hamling (published in July in BMC Medicine) and to discuss the anticipated direction of the debate on tobacco-harm reduction in the USA. We anticipate that much of the debate will shift from the discussion of epidemiologic data to the discussion of the marketing, health communication and economics of smokeless tobacco. While the Food and Drug Administration's newly approved authority over tobacco will undoubtedly affect the smokeless products, it may not be the sole determinant of harm reduction's fate in the USA. See associated research article by Lee and Hamling: http://www.biomedcentral.com/1741-7015/7/36.

Are smokers receptive to using smokeless tobacco as a substitute?

OBJECTIVES

Few studies have addressed the feasibility of promoting smokeless tobacco as an alternative for smokers. This study was intended to assess the characteristics and degree to which smokers from California are receptive to using the substitute for harm reduction.

METHODS

Daily cigarette smokers (n=2995) were selected from the 2005 California Tobacco Survey. Using ordinal logistic regression, four sets of variables (demographics, tobacco use, motivations and intentions to quit smoking) were examined as predictors of the outcome, willingness to use a form of smokeless tobacco perceived to be less harmful than cigarettes.

RESULTS

A majority of smokers (75.6%) expressed no interest in the tobacco substitute. Contrary to expectation, few of the measures for demographics, tobacco use and motivations to quit smoking were significantly correlated with the outcome. Irrespective of prior use of nicotine replacement therapy, smokers were more receptive if they had previously attempted to quit, or were currently attempting to reduce their consumption of cigarettes.

CONCLUSIONS

Smokeless tobacco is an unacceptable alternative for most California smokers. But, the expected correlates, notably gender, accounted for minimal variability in SLT receptiveness, an observation that challenges concerns about the product's limited appeal to any one group.

Demographic profiles of smokeless tobacco users in the U.S

BACKGROUND

Users of smokeless tobacco (chew or snuff) in the U.S. are viewed demographically as being homogeneous. Prior studies have demonstrated such homogeneity in national survey data but have not utilized latent-variable methods. The objective of this study was to determine whether a single group or underlying subgroups best characterize users of smokeless tobacco.

METHODS

Men aged >17 years who had used smokeless tobacco in the past month (n=4583) were selected from the 2003, 2004, and 2005 National Surveys on Drug Use and Health. A latent-class analysis, conducted in 2008, was based on individual response patterns from six demographic variables and three items pertaining to the use of smokeless tobacco.

RESULTS

Four latent classes were identified: older chew users (17.2%); younger poly-tobacco users (28.7%); skilled laborers with a high school diploma (27.5%); and educated professionals (26.6%). External validation of these classes indicated that older chew users and younger poly-tobacco users were more likely than the educated professionals to be former and current smokers, respectively.

CONCLUSIONS

While users of smokeless tobacco in the U.S. are predominantly white men, they are more heterogeneous with respect to education, occupation, and residency than commonly is perceived.

Use of snus and risk for cardiovascular disease: results from the Swedish Twin Registry

OBJECTIVE

To study the association between snus use and the risk for cardiovascular disease, i.e. ischemic heart disease and stroke.

DESIGN

Cohort study.

SETTING

Sweden.

SUBJECTS

Sixteen thousand six hundred and forty-two male Swedish twins participating in the Screening Across the Lifespan Twin Study, conducted in 1998- 2002, were followed for incident cardiovascular disease. Participants were without a history of cardiovascular disease at baseline and incident cases were identified via the Swedish Cause of Death Register and Hospital Discharge Register.

RESULTS

Overall, there was no association between use of snus and risk for cardiovascular disease. Current snus users, without a smoking history, had a relative risk of 1.00 (95% confidence interval 0.69-1.46) for cardiovascular disease as compared to non users. Corresponding relative risks for ischemic heart disease and stroke were 0.85 (95% confidence interval 0.51-1.41) and 1.18 (95% confidence interval 0.67-2.08), respectively. In smoking adjusted models, risk estimates for ischemic heart disease in relation to snus use were all close to unity regardless of timing or intensity of snus use. However, current heavy snus users (consuming more than four cans week(-1)) had a relative risk for stroke of 1.75 (95% confidence interval 0.95-3.21).

CONCLUSION

These data do not support any strong association between snus use and risk for cardiovascular disease.

The STAGE cohort: a prospective study of tobacco use among Swedish twins

We investigated patterns of cigarette smoking and Swedish snus (oral smokeless tobacco) use in a population-based sample of 19,073 Swedish twins 20-47 years old who participated in the baseline assessment of a prospective study of tobacco use and cessation in 2005-2006. Age-adjusted prevalence odds ratios (POR) and 95% confidence intervals (CI ) describe the association between tobacco use and sex, after adjustment for non-independence of twin pairs. Kaplan-Meier survival methods produced cumulative incidence curves of age at initiation of tobacco use. Slightly more than half of the baseline population was female (55.2%); the mean age at interview was 33.3 (+/-7.2) years and did not differ by sex. Having ever smoked daily was less common among males than females (11.9% vs. 15.3%; POR = 0.70 [0.64-0.77]), while having ever used snus daily was more common among males than females (31.1% vs. 4.8%; POR 11.7 [95% CI = 10.6-13.1]). The median age at initiation of smoking was 15 years for both sexes; median age at onset of snus use was 15 years for males and 18 years for females. Nicotine dependence scores were higher for males than females, and for current than former smokers. Findings from this study are in contrast to our previously published report on tobacco use among 32,123 Swedish twins 42-64 years old who completed a similar survey, and reported lower rates of snus use at later ages. Patterns of tobacco use may be changing in Sweden; snus use appears to be increasing, while daily smoking appears to be decreasing in popularity among the younger Swedish twins.

Quitting cigarettes completely or switching to smokeless tobacco: do US data replicate the Swedish results?

BACKGROUND

Swedish male smokers are more likely than female smokers to switch to smokeless tobacco (snus) and males' smoking cessation rate is higher than that of females. These results have fuelled international debate over promoting smokeless tobacco for harm reduction. This study examines whether similar results emerge in the United States, one of few other western countries where smokeless tobacco has long been widely available.

METHODS

US DATA SOURCE: national sample in Tobacco Use Supplement to Current Population Survey, 2002, with 1-year follow-up in 2003. Analyses included adult self-respondents in this longitudinal sample (n = 15,056). Population-weighted rates of quitting smoking and switching to smokeless tobacco were computed for the 1-year period.

RESULTS

Among US men, few current smokers switched to smokeless tobacco (0.3% in 12 months). Few former smokers turned to smokeless tobacco (1.7%). Switching between cigarettes and smokeless tobacco, infrequent among current tobacco users (<4%), was more often from smokeless to smoking. Men quit smokeless tobacco at three times the rate of quitting cigarettes (38.8% vs 11.6%, p<0.001). Overall, US men have no advantage over women in quitting smoking (11.7% vs 12.4%, p = 0.65), even though men are far likelier to use smokeless tobacco.

CONCLUSION

The Swedish results are not replicated in the United States. Both male and female US smokers appear to have higher quit rates for smoking than have their Swedish counterparts, despite greater use of smokeless tobacco in Sweden. Promoting smokeless tobacco for harm reduction in countries with ongoing tobacco control programmes may not result in any positive population effect on smoking cessation.

Is smokeless tobacco use an appropriate public health strategy for reducing societal harm from cigarette smoking?

Four arguments have been used to support smokeless tobacco (ST) for harm reduction: (1) Switching from cigarettes to ST would reduce health risks; (2) ST is effective for smoking cessation; (3) ST is an effective nicotine maintenance product; and (4) ST is not a "gateway" for cigarette smoking. There is little evidence to support the first three arguments and most evidence suggests that ST is a gateway for cigarette smoking. There are ethical challenges to promoting ST use. Based on the precautionary principle, the burden of proof is on proponents to provide evidence to support their position; such evidence is lacking.

Snus use and other correlates of smoking cessation in the Swedish Twin Registry

BACKGROUND

We investigated 12 variables and their interactions as correlates of smoking cessation among regular smokers in the population-based Swedish Twin Registry (STR).

METHOD

Detailed information on tobacco use and personal characteristics were available from 14 715 male and female twins aged 42-64 years who participated in a screening of the population-based STR and reported being regular smokers in their lifetime. A two-stage analytic design was used to examine correlates of smoking cessation. The sample was split at random and significant main effects and interactions identified in the testing set were examined in the validation set. Hazard ratios (HRs) and 95% confidence intervals (CIs) describe the association between correlates and smoking cessation.

RESULTS

Twelve main effects were significantly associated with smoking cessation in the testing set; eight were confirmed in the validation set. Of the nine interactions identified in the testing set, none remained significant when evaluated in the validation set after Bonferroni correction. HRs were highest for Swedish oral smokeless tobacco (snus) use (HR 2.70, 95% CI 2.30-3.20), >11 years of education (HR 1.57, 95% CI 1.43-1.73) and being married or cohabitating (HR 1.51, 95% CI 1.39-1.63). Although not statistically significant after Bonferroni correction, snus use also appeared important in the context of interactions, where lower nicotine dependence score, higher socio-economic status (SES) and greater body size were associated with smoking cessation only among participants who never used snus.

CONCLUSIONS

Snus use was the strongest independent correlate of smoking cessation. Further studies should investigate the mechanism of this association.

Is low-nicotine Marlboro snus really snus?

Swedish snus is a medium/high nicotine delivery, low-nitrosamine moist smokeless tobacco product that has been estimated to be at least 90% less harmful than smoked tobacco. More men use snus than smoke cigarettes in Sweden, and a quarter of male former smokers quit by switching to snus. Leading multinational cigarette manufacturers have begun test-marketing snus-like products in the United States and other countries. The version of Philip Morris' Marlboro snus currently being marketed in the United States differs from Swedish snus in many ways; it has lower moisture content and pH, but most puzzling is its very low nicotine delivery. Philip Morris, the market-leader in United States cigarette sales, may have designed the product so that it does not satisfy nicotine cravings and fails to enable smokers to switch. In this paper we compare and contrast Swedish snus and Marlboro snus, and speculate as to why Philip Morris may have intentionally designed a product that delivers very low levels of nicotine. We recommend that Philip Morris cease using the term "snus" to refer to dry tobacco products with low nicotine delivery, so that the term be reserved for moist, low-toxin, medium/high nicotine delivery smokeless tobacco products that are qualitatively similar to the leading brands in Sweden.