Snus use and smoking behaviors: preliminary findings from a prospective cohort study among US Midwest young adults

Efficacy of smokeless tobacco for smoking cessation: a systematic review and meta-analysis

OBJECTIVE

Smoking remains prevalent in many countries despite rigorous tobacco control strategies. The use of Swedish snus, a type of low-nitrosamine smokeless tobacco, has been promoted as a tobacco harm reduction strategy.

DATA SOURCES AND STUDY SELECTION

Three databases were searched for studies that assessed the effectiveness of snus in promoting smoking abstinence. A total of 28 studies were reviewed (5 randomised controlled trials (RCTs), 7 longitudinal and 16 cross-sectional studies).

DATA EXTRACTION

Separate meta-analyses were conducted by study type, pooling effect estimates where outcome measures and design were sufficiently comparable. Study details and quality assessment (Risk of Bias 2 for RCTs, Newcastle-Ottawa Scale for observational studies) are provided for each study.

DATA SYNTHESIS

While the meta-analysis of RCTs did not show a significant association between snus use and smoking cessation (risk ratio (RR)=1.33, 95% CI 0.71 to 2.47 and RR=0.62, 95% CI 0.27 to 1.41), the results of the meta-analysis of longitudinal cohort studies (RR=1.38, 95% CI 1.05 to 1.82, p=0.022) and cross-sectional studies (OR=1.87, 95% CI 1.29 to 2.72, p=0.001) indicated that use of snus was associated with an increased likelihood of quitting or having quit smoking. There was significant heterogeneity in the cross-sectional studies, and leave-one-out analysis indicated that the longitudinal cohort results were driven by one study. Most studies examined were subject to an elevated risk of bias.

CONCLUSION

There is weak evidence for the use of snus for smoking cessation. Better RCTs and longitudinal studies are needed; meanwhile, existing cessation aids may be better placed than snus to promote abstinence.

Trends in Awareness, Use of, and Beliefs About Electronic Cigarette and Snus Among a Longitudinal Cohort of US Midwest Young Adults

Introduction

Few longitudinal studies have examined how awareness, use of, and beliefs about electronic cigarettes (e-cigarettes) and snus change over time. We assessed these trends in a cohort of young adults from the US Midwest.

Methods

Data were from the Minnesota Adolescent Community Cohort (MACC) Study, collected annually during 2010-2013 when participants were 21-29 years old (n = 2622). Participants were asked if they had heard of and ever used e-cigarettes and snus, and the number of days they used these products in the past 30 days. Beliefs about whether these products are less harmful than cigarettes, less addictive than cigarettes, and could help people quit smoking were assessed. Repeated measures multiple linear and logistic regression models, adjusting for demographics, peer smoking and smoking status, were used to assess trends.

Results

Compared to 2010-2011, participants in 2012-2013 were five times more likely to be aware of e-cigarettes, report ever used them, and report using them in the past 30-days. Increases in e-cigarette use were observed in all smoking status. Participants were also increasingly likely to believe that e-cigarettes are less harmful than combustible cigarettes and could help people quit smoking. There was only a modest increase in awareness of and ever using snus, as well as believing snus is less harmful than combustible cigarettes. These trends did not differ by smoking status.

Conclusions

The increasingly favorable beliefs about e-cigarettes may explain the increasing prevalence of their use particularly among young adults, both among smokers and nonsmokers.

Implications

Awareness and use of e-cigarettes have increased substantially over the past few years, and positive beliefs of e-cigarettes have also become more prevalent among young adults. Meanwhile, little changes in awareness, use of, and beliefs about snus among young adults. Given the potential of these products to have both positive and negative impact on public health depending on who use them and how they are used, strategically communicating the risks associated with e-cigarettes and snus use may help minimize the burden of tobacco use at the population level.

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

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

Acute effects of snus in never-tobacco users: a pilot study

BACKGROUND

Snus tobacco characteristics may attract non-tobacco users, including relatively low, but pharmacologically active, doses of nicotine. Lower nicotine doses may limit adverse drug effects while also producing a physiologically active response.

OBJECTIVES

This pilot study is the first to profile the acute effects of snus on physiological and subjective assessments in a sample of never-tobacco users.

METHODS

Eleven never-tobacco users (five women; <100 uses/lifetime) were recruited from the community via university-approved advertisements. Using a within-subject design, participants consumed six pouches in ascending dose order (0, 1.6, 3.2, 4.8, 6.4, and 8.0 mg nicotine) within one session. The start of each snus bout was separated by 45 minutes, and pre- and post-pouch assessments included ratings of drug effects and physiological response.

RESULTS

The average heart rate and systolic blood pressure increased significantly from pre- to post-pouch use as a function of dose, though these increases were reliable for 8.0 mg nicotine only (p < .05). Collapsed across time, diastolic blood pressure was significantly higher for 8.0 mg nicotine than for all other doses (p < .05). Subjective ratings for "excessive salivation" and "satisfying" increased significantly from pre- to post-pouch use (p < .05), independent of dose.

CONCLUSION

Significant increases in physiological response at some doses suggest that users were exposed to pharmacologically active doses of nicotine. The lack of reliable subjective effects may be the product of the dosing regimen or the relatively small sample size. Findings highlight the need for identification of doses of snus that may promote abuse among naïve users.

The Effect of Comparatively-Framed versus Similarity-Framed E-Cigarette and Snus Print Ads on Young Adults' Ad and Product Perceptions

OBJECTIVES

This study examined the effects of comparative-framing [C-F; ads highlighting differences between the advertised product and conventional cigarettes and/or smokeless tobacco products] versus similarity-framing (S-F; ads highlighting congruence with conventional cigarettes and/or smokeless tobacco products) in e-cigarette and snus ads on young adult smokers' and non-smokers' ad- and product-related perceptions.

METHODS

One thousand fifty one (1,051) young adults (18-24 years; 76% women; 50% smokers) from existing consumer panels were recruited in a within-subjects quasi-experiment. Each participant viewed 4 online advertisements, varied by tobacco product type (e-cigarette or snus) and ad framing (C-F or S-F). The dependent measures for this study were ad-related (ad perceptions, ad credibility) and product-related perceptions (absolute and comparative risk perceptions, product appeal, and product use intentions).

RESULTS

Former and current smokers rated C-F ads as more persuasive than S-F ads, as evidenced by favorable ad perceptions and high product use intentions. Former and current smokers also rated e-cigarette ads with more favorable ad perceptions, low absolute and comparative risk perceptions, high product appeal, and high product use intentions as compared to snus ads. However, the effect sizes of the significant differences are less than.2, indicating small magnitude of difference between the study variables.

CONCLUSIONS

Unless FDA regulates e-cig and snus advertising, there is a potential of decreasing risk perceptions and increasing use of e-cigs among young adults. Further research on implicit/explicit comparative claims in e-cigarettes and snus advertisements that encourage risk misperceptions is recommended.

The Impact of Health Warning Labels for Swedish Snus Advertisements on Young Adults' Snus Perceptions and Behavioral Intentions

INTRODUCTION

This study examined the impact of warning labels conveying the potential harms and addictiveness of Swedish snus and the potential-reduced harms of Swedish snus among young adult nonsmokers and smokers.

METHODS

A convenience sample of young adults aged 18-30 residing in the United States (n = 517, 56% male, 33% smokers) participated in an online experiment. Participants completed baseline measures and were randomized to 1 of 5 experimental conditions where they viewed a Swedish snus ad with warning labels that varied by condition: (1) Control-no warning; (2) Addiction-warning conveying the addictiveness of snus; (3) Harm-warning communicating the potential harms of snus; (4) Harm Reduction-warning conveying the potential-reduced harms of snus compared with cigarettes; (5) Harm Reduction Switch-warning communicating the potential-reduced harms of snus when switching completely from cigarettes to snus. Outcomes measured included perceived harms and addictiveness of snus, thoughts about not using snus, and intentions to use snus.

RESULTS

Participants in the Harm Reduction and Harm Reduction Switch conditions perceived snus to be less harmful than cigarettes compared with the Control, Addiction, and Harm conditions. Nonsmokers in the Harm Reduction condition reported fewer thoughts about not using snus than nonsmokers in the Harm condition.

CONCLUSIONS

Warnings conveying the potential-reduced harms of Swedish snus compared with cigarettes generate perceptions that snus is less harmful than cigarettes and produce fewer thoughts about not using snus among nonsmokers. Such perceptions have been associated with snus use in prior studies.

A Risk-Continuum Categorization of Product Use Among US Youth Tobacco Users

INTRODUCTION

To examine prevalence and correlates of five mutually exclusive tobacco-use patterns among US youth tobacco users.

METHODS

A nationally representative sample of tobacco users (N = 3202, 9-17 years) was classified into five product-use patterns. Weighted multinominal and multivariate logistic regression models were used to examine prevalence of product-use patterns by gender, race and ethnicity, and grade level; and associations between product-use patterns and perceived accessibility of tobacco products, exposure and receptivity to pro-tobacco marketing, social benefits of smoking, and tobacco-associated risks.

RESULTS

Dual use (ie, use of two product categories) was the most prevalent pattern (30.5%), followed by non-cigarette combustible only (26.7%), polytobacco (ie, use of three product categories; 17.5%), cigarette only (14.9%), and noncombustible only (10.4%) use. Product-use patterns differed by gender, race, and ethnicity. Compared to cigarette only users, dual and polytobacco users were more likely to be exposed to and be receptive to pro-tobacco marketing, and were less likely to acknowledge tobacco-use related risks (Ps < .05).

CONCLUSIONS

Curbing tobacco use warrants research on users of more than one tobacco-product categories according to the risk-continuum categorization.

IMPLICATIONS

We present a risk-continuum categorization of product-use patterns among tobacco users not older than 17 years. We classify tobacco users into five mutually exclusive product-use patterns: cigarette only users, non-cigarette combustible only users, noncombustible only users, dual use, and polytobacco use. This categorization overcomes limitations in current literature on tobacco-use patterns, which include exclusion of certain products (eg, e-cigarettes) and product-use patterns (eg, exclusive users of non-cigarette products), and inconsistent classification of tobacco users. It is parsimonious yet complex enough to retain differential characteristics of sub-tobacco users based on number (single, dual, polytobacco) and categories (cigarettes, non-cigarette combustibles, noncombustibles) of tobacco products consumed.