Estimating the Population Health Impact of Recently Introduced Modified Risk Tobacco Products: A Comparison of Different Approaches

Predicting the long-term effects of electronic cigarette use on population health: a systematic review of modelling studies

OBJECTIVE

To systematically review and synthesise the findings of modelling studies on the population impacts of e-cigarette use and to identify potential gaps requiring future investigation.

DATA SOURCE AND STUDY SELECTION

Four databases were searched for modelling studies of e-cigarette use on population health published between 2010 and 2023. A total of 32 studies were included.

DATA EXTRACTION

Data on study characteristics, model attributes and estimates of population impacts including health outcomes and smoking prevalence were extracted from each article. The findings were synthesised narratively.

DATA SYNTHESIS

The introduction of e-cigarettes was predicted to lead to decreased smoking-related mortality, increased quality-adjusted life-years and reduced health system costs in 29 studies. Seventeen studies predicted a lower prevalence of cigarette smoking. Models that predicted negative population impacts assumed very high e-cigarette initiation rates among non-smokers and that e-cigarette use would discourage smoking cessation by a large margin. The majority of the studies were based on US population data and few studies included factors other than smoking status, such as jurisdictional tobacco control policies or social influence.

CONCLUSIONS

A population increase in e-cigarette use may result in lower smoking prevalence and reduced burden of disease in the long run, especially if their use can be restricted to assisting smoking cessation. Given the assumption-dependent nature of modelling outcomes, future modelling studies should consider incorporating different policy options in their projection exercises, using shorter time horizons and expanding their modelling to low-income and middle-income countries where smoking rates remain relatively high.

A Descriptive Analysis of Beliefs About Nicotine and Switching to Noncombustibles Among Adults Who Smoke Cigarettes and Believe Nicotine Causes Cancer

Introduction: Many people who smoke cigarettes report believing that nicotine causes cancer, a misperception that may reduce interest in switching to noncombustible nicotine products. Quantitative survey questions do not capture how this population thinks about nicotine and switching to noncombustible products. Methods: This study used an online convenience sample of 193 US adults who smoke cigarettes and reported that nicotine causes cancer. Respondents were asked if they thought nicotine was harmful (and why or why not) and if they would consider switching to a noncombustible product (and why or why not). Inductive and deductive coding were used, and descriptive statistics are reported. Results: Descriptions of nicotine directly causing disease (61%) were more common than descriptions of nicotine causing addiction to a harmful product (8%). One-third expressly stated that nicotine causes cancer, and 21% that nicotine causes lung disease. Interest in switching was moderate (mean 47.4 out of 100). When asked about switching, 34% described enjoying their current smoking experience, 23% described a perceived health benefit, 16% described a health concern, and 11% worried that switching would not address nicotine addiction. Discussion: Adults who smoke commonly perceived nicotine as a direct cause of cigarette-related disease, and harm and addictiveness perceptions were often mentioned as reasons for interest or disinterest in switching to a noncombustible. Future studies could explore strategies for correcting nicotine misperception, stigma related to addiction, and common concerns related to health as well as user experience.

Modeling the population health impact of accurate and inaccurate perceptions of harm from nicotine

BACKGROUND

Scientific evidence clearly demonstrates that inhaling the smoke from the combustion of cigarettes is responsible for most of the harm caused by smoking, and not the nicotine. However, a majority of U.S. adults who smoke inaccurately believe that nicotine causes cancer which may be a significant barrier, preventing switching to potentially reduced risk, non-combustible products like electronic nicotine delivery systems (ENDS) and smokeless tobacco (ST). We assessed the population health impact associated with nicotine perceptions.

METHODS

Using a previously validated agent-based model to the U.S. population, we analyzed nationally representative data from the Population Assessment of Tobacco and Health (PATH) study to estimate base case rates of sustained (maintained over four waves) cessation and switching to non-combustible product use, by sex. Nicotine perception scenarios were determined from PATH data. The overall switch rate from smoking in Wave 4 to non-combustible product use in Wave 5 (3.94%) was stratified based on responses to the nicotine perception question "Do you believe nicotine is the chemical that causes most of the cancer caused by smoking cigarettes?", (four-item scale from "Definitely not" to "Definitely yes"). The relative percent change between the overall and stratified rates, corresponding to each item, was used to adjust the base case rates of switching, to determine the impact, if all adults who smoke exhibited switching behaviors based on responses to the nicotine perceptions question. The public health impact of nicotine perceptions was estimated as the difference in all-cause mortality between the base case and the four nicotine perception scenarios.

RESULTS

Switch rates associated with those who responded, "Definitely not" (8.39%) resulted in a net benefit of preventing nearly 800,000 premature deaths over an 85-year period. Conversely switch rates reflective of those who responded, "Definitely yes" (2.59%) resulted in a net harm of nearly 300,000 additional premature deaths over the same period.

CONCLUSIONS

Accurate knowledge regarding the role of nicotine is associated with higher switch rates and prevention of premature deaths. Our findings suggest that promoting public education to correct perceptions of harm from nicotine has the potential to benefit public health.

A Scoping Review of Behavioural Studies on Heated Tobacco Products

Heated tobacco products (HTPs) are electronic devices that heat tobacco sticks to temperatures much lower than those which cause pyrolysis and combustion in cigarettes. While this electrical heating causes the formation of an inhalable aerosol which contains nicotine, the aerosol from HTPs contains significantly fewer and lower levels of the harmful and potentially harmful chemicals found in cigarette smoke. As a result, HTP use potentially conveys reduced risks to health compared to cigarette smoking. While this relative reduction in individual health risk is becoming clearer, what is less certain is the impact of HTPs on overall population‑level health, taking into account both the potential positive impact on adult smokers who completely switch to using HTPs and any unintended impacts such as use by tobacco non‑users and particularly by youth. The aim of this scoping review was to collate and evaluate the published scientific evidence to date, with a cut‑off of 1 January 2024, investigating the impact of HTPs on population‑level health. This evaluation suggests that HTP use is almost exclusively observed among those with a history of cigarette smoking, and there is a growing body of evidence for the ability of HTPs to provide support for adult smokers to transition away from cigarette smoking, in the absence of any significant "gateway" into tobacco use initiation. Many studies have reported a significant degree of dual use of cigarettes and HTPs, and efforts to assess the reasons for such patterns of use, whether these provide overall exposure reductions, and whether dual use acts as a bridge towards a complete transition away from cigarette smoking, requires further investigation. In addition, correction of the widespread and increasing misperceptions of HTPs among adult smokers is recommended to promote HTP uptake as a potentially less harmful alternative to smoking in this population.

Evidence relating cigarettes, cigars and pipes to cardiovascular disease and stroke: Meta-analysis of recent data from three regions

BACKGROUND

More recent data are required relating to disease risk for use of various smoked products and of other products containing nicotine. Earlier we published meta-analyses of recent results for chronic obstructive pulmonary disease and lung cancer on the relative risk (RR) of current compared to never product use for cigarettes, cigars and pipes based on evidence from North America, Europe and Japan. We now report corresponding up-to-date evidence for acute myocardial infarction (AMI), ischaemic heart disease (IHD) and stroke.

AIM

To estimate, using recent data, AMI, IHD and stroke RRs by region for current smoking of cigarettes, cigars and pipes.

METHODS

Publications in English from 2015 to 2020 were considered that, based on epidemiological studies in the three regions, estimated the current smoking RR of AMI, IHD or stroke for one or more of the three products. The studies should involve at least 100 cases of stroke or cardiovascular disease (CVD), not be restricted to populations with specific medical conditions, and should be of cohort or nested case-control study design or randomized controlled trials. A literature search was conducted on MEDLINE, examining titles and abstracts initially, and then full texts. Additional papers were sought from reference lists of selected papers, reviews and meta-analyses. For each study identified, we entered the most recent available data on current smoking of each product, as well as the characteristics of the study and the RR estimates. Combined RR estimates were derived using random-effects meta-analysis for stroke and, in the case of CVD, separately for IHD and AMI. For cigarette smoking, where far more data were available, heterogeneity was studied by a wide range of factors. For cigar and pipe smoking, a more limited heterogeneity analysis was carried out. A more limited assessment of variation in risk by daily number of cigarettes smoked was also conducted. Results were compared with those from previous meta-analyses published since 2000.

RESULTS

Current cigarette smoking: Ten studies gave a random-effects RR for AMI of 2.72 [95% confidence interval (CI): 2.40-3.08], derived from 13 estimates between 1.47 and 4.72. Twenty-three studies gave an IHD RR of 2.01 (95%CI: 1.84-2.21), using 28 estimates between 0.81 and 4.30. Thirty-one studies gave a stroke RR of 1.62 (95%CI: 1.48-1.77), using 37 estimates from 0.66 to 2.91. Though heterogeneous, only two of the overall 78 RRs were below 1.0, 71 significantly (P < 0.05) exceeding 1.0. The heterogeneity was only partly explicable by the factors studied. Estimates were generally higher for females and for later-starting studies. They were significantly higher for North America than Europe for AMI, but not the other diseases. For stroke, the only endpoint with multiple Japanese studies, RRs were lower there than for Western studies. Adjustment for multiple factors tended to increase RRs. Our RR estimates and the variations by sex and region are consistent with earlier meta-analyses. RRs generally increased with amount smoked. Current cigar and pipe smoking: No AMI data were available. One North American study reported reduced IHD risk for non-exclusive cigar or pipe smoking, but considered few cases. Two North American studies found no increased stroke risk with exclusive cigar smoking, one reporting reduced risk for exclusive pipe smoking (RR 0.24, 95%CI: 0.06-0.91). The cigar results agree with an earlier review showing no clear risk increase for IHD or stroke.

CONCLUSION

Current cigarette smoking increases risk of AMI, IHD and stroke, RRs being 2.72, 2.01 and 1.62. The stroke risk is lower in Japan, no increase was seen for cigars/pipes.

The Potential Impact of E-cigarettes on the Life-Years Lost from Conventional Smoking in the Russian Federation

This study analyses the potential impact of e-cigarettes on the death toll of cigarette smoking in the Russian Federation by working under a variety of assumptions pertaining to how much vaping might affect smoking cessation and initiation, and its adverse impacts on health in comparison to conventional smoking. Within this study, each combination of these assumptions generates a single vaping scenario (210 in total). A dynamic population simulation model, specifically for the Russian Federation, that is tailoured to tobacco control policy analysis, is built for estimation purposes. Considering the toll of smoking on cumulative life-years saved via the inclusion of vaping across a period of 80 years, the simulation analysis produces positive results in 88.1% of e-cigarette scenarios, ranging from - 3.3 million to 38.5 million life-years saved. In relative terms, the estimated life-years saved from vaping varies from - 1.6 to 18.6% of the predicted life-years lost from smoking. Most of the model scenarios involve a significant number of individuals who stopped smoking in favour of vaping. These results suggest that vaping has great potential to reduce the prevalence of smoking and the related death toll in the Russian Federation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10603-023-09540-z.

Efficacy and Safety of E-Cigarette Use for Smoking Cessation: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

People who smoke conventional cigarettes are increasingly turning to electronic cigarettes (e-cigarettes) as a pathway to quitting, however the efficacy and safety of e-cigarettes for smoking cessation remains controversial.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs), identified through a systematic search of the MEDLINE, EMBASE, and Cochrane CENTRAL databases. Inclusion was restricted to RCTs with a follow-up duration ≥ 6 months. The primary endpoint was the most rigorous criterion of biochemically validated abstinence at maximum follow-up, and the primary comparison was nicotine e-cigarettes versus any conventional (i.e., non-e-cigarette) smoking cessation therapy. The Cochrane Risk of Bias Tool was used to assess bias. Count data were pooled across trials using random-effects models with inverse variance weighting to estimate relative risks (RRs) and corresponding 95% confidence intervals (CIs). We registered the study protocol with the Open Science Framework Registries (osf.io/26fkq).

RESULTS

A total of 5 RCTs (n=3,253) were included. Compared with conventional smoking cessation therapies, the use of nicotine e-cigarettes was associated with an increase in abstinence, defined by the most rigorous criterion of abstinence reported (RR: 1.77; 95% CI: 1.29-2.44). Nicotine e-cigarettes also increased abstinence (defined by the most rigorous criterion) compared to non-nicotine e-cigarettes (RR: 1.56; 95% CI: 1.13-2.15). The incidence of death or SAEs was low across all trials at maximum follow-up.

CONCLUSIONS

Among individuals attempting to quit smoking, nicotine e-cigarettes are more efficacious than conventional nicotine replacement or behavioral smoking cessation therapies and may prove beneficial in reducing smoking-related health risks.

A Decision-Theoretic Public Health Framework for Heated Tobacco and Nicotine Vaping Products

Markets for nicotine vaping products (NVPs) and heated tobacco products (HTPs) have grown as these products became positioned as harm-reduction alternatives to combusted tobacco products. Herein, we present a public health decision-theoretic framework incorporating different patterns of HTP, NVP, and cigarette use to examine their impacts on population health. Our framework demonstrates that, for individuals who would have otherwise smoked, HTP use may provide public health benefits by enabling cessation or by discouraging smoking initiation and relapse. However, the benefits are reduced if more harmful HTP use replaces less harmful NVP use. HTP use may also negatively impact public health by encouraging smoking by otherwise non-smokers or by encouraging initiation or relapse into smoking. These patterns are directly influenced by industry behavior as well as public policy towards HTPs, NVPs, and cigarettes. While substantial research has been devoted to NVPs, much less is known about HTPs. Better information is needed to more precisely define the health risks of HTPs compared to cigarettes and NVPs, the relative appeal of HTPs to consumers, and the likelihood of later transitioning to smoking or quitting all products. While our analysis provides a framework for gaining that information, it also illustrates the complexities in distinguishing key factors.

Estimating the public health impact had tobacco-free nicotine pouches been introduced into the US in 2000

BACKGROUND

For smokers not intending to quit, switching to a reduced-risk nicotine product should be healthier than continuing smoking. We estimate the health impact, over the period 2000-2050, had the nicotine pouch ZYN hypothetically been introduced into the US in 2000. ZYN's toxicant profile and method of use is like that for Swedish snus, a product with known health effects much less than smoking.

METHODS

Our modelling approach is similar to others developed for estimating potential effects of new tobacco products. It starts with a simulated cohort of 100,000 individuals in the year 2000 subdivided by age, sex, and smoking status (including years since quitting). They are followed annually accounting for births, net immigrations, deaths and product use changes, with follow-up carried out in the Base Case (ZYN not introduced) and Modified Case (ZYN introduced). Using informed assumptions about initiation, quitting and switching rates, distributions of the population over time are then constructed for each Case, and used to estimate product mortality based on assumptions about the relative risk according to product use.

RESULTS

Whereas in both Base and Modified Cases, the prevalence of any current product use is predicted to decline from about 22% to 10% during follow-up, in the Modified Case about 25% of current users use ZYN by 2050, about a quarter being dual users and the rest ZYN-only users. Over the 50 years, deaths at ages 35-84 from product use among the 100,000 are estimated as 249 less in the Modified than the Base Case, equivalent to about 700,000 less in the whole US. Sensitivity analyses varying individual parameter values confirm the benefits of switching to ZYN, which increase as either the switching rate to ZYN increases or the initiation rate of ZYN relative to smoking increases. Even assuming the reduction in excess mortality risk using ZYN use is 20% of that from smoking rather than the 3.5% assumed in the main analyses, the reduction in product-related deaths would still be 213, or about 600,000 in the US.

CONCLUSIONS

Although such model-based estimates involve uncertainties, the results suggest that introducing ZYN could substantially reduce product-related deaths.

Developing Competency-Based Nursing Treatment for Persons With Tobacco Use Disorder

BACKGROUND

Tobacco continues to have a deleterious impact on health outcomes in the United States. Professional nurses at all levels of practice have an opportunity to be a part of the solution. The development of nurse-specific competencies for treating tobacco use disorder (TUD) disorder is long overdue. A task force of American Psychiatric Nurses Association (APNA) subject matter experts was assembled to engage in the process of reviewing the available peer-reviewed literature and additional evidence-based resources (e.g., professional organization position statement, toolkits, national survey results) to create the Nursing Competencies for Treating Tobacco Use Disorders.

OBJECTIVE

The aim of this article is ultimately to improve patient access to quality, evidence-based TUD nursing care by all nurses who are competent, full partners in TUD multidisciplinary care.

METHOD

Search terms were defined and a scoping search and review of the TUD literature and resources was performed from November 2018 to November 2020.

RESULTS

Over 300 articles and evidence-based resources (e.g., professional organization position statements, toolkits, etc.) were discovered. Thirteen competencies were developed and were internally and externally reviewed prior to APNA Board of Director's approval.

CONCLUSION

TUD competencies have the potential to guide nursing education, practice, and research, allowing nurses to be full partners in the design, development, and implementation of effective TUD treatment.

Investigating the Health Effects of 3 Coexisting Tobacco-Related Products Using System Dynamics Population Modeling: An Italian Population Case Study

With the proliferation of tobacco products, there might be a need for more complex models than current two-product models. We have developed a three-product model able to represent interactions between three products in the marketplace. We also investigate if using several implementations of two-product models could provide sufficient information to assess 3 coexisting products. Italy is used as case-study with THPs and e-cigarettes as the products under investigation. We use transitions rates estimated for THPs in Japan and e-cigarettes in the USA to project what could happen if the Italian population were to behave as the Japanese for THP or USA for e-cigarettes. Results suggest that three-product models may be hindered by data availability while two product models could miss potential synergies between products. Both, THP and E-Cigarette scenarios, led to reduction in life-years lost although the Japanese THP scenario reductions were 3 times larger than the USA e-cigarette projections.

Balancing Consideration of the Risks and Benefits of E-Cigarettes

The topic of e-cigarettes is controversial. Opponents focus on e-cigarettes' risks for young people, while supporters emphasize the potential for e-cigarettes to assist smokers in quitting smoking. Most US health organizations, media coverage, and policymakers have focused primarily on risks to youths. Because of their messaging, much of the public-including most smokers-now consider e-cigarette use as dangerous as or more dangerous than smoking. By contrast, the National Academies of Science, Engineering, and Medicine concluded that e-cigarette use is likely far less hazardous than smoking. Policies intended to reduce adolescent vaping may also reduce adult smokers' use of e-cigarettes in quit attempts. Because evidence indicates that e-cigarette use can increase the odds of quitting smoking, many scientists, including this essay's authors, encourage the health community, media, and policymakers to more carefully weigh vaping's potential to reduce adult smoking-attributable mortality. We review the health risks of e-cigarette use, the likelihood that vaping increases smoking cessation, concerns about youth vaping, and the need to balance valid concerns about risks to youths with the potential benefits of increasing adult smoking cessation.

A Magic Bullet? The Potential Impact of E-Cigarettes on the Toll of Cigarette Smoking

INTRODUCTION

We examine the proportion of US smoking-produced mortality that e-cigarettes might eliminate under assumptions regarding vaping's ability to increase smoking cessation, vaping's health risks, and the possibility that vaping will increase smoking among young people.

METHODS

We employ a dynamic population simulation model that tracks individuals from ages 0 to 110, differentiated by gender and smoking status. Using data from the US Census, the National Vital Statistics Reports, Cancer Prevention Study II, and the National Health Interview Survey, we estimate the number of smoking-related life-years lost (LYL) from 2018 to 2100 in a no-vaping scenario. We then compare results for model runs that assess the impact of vaping under a variety of assumptions.

RESULTS

The combination of assumptions produces 360 possible scenarios. 357 (99%) yield positive estimates of life-years saved (LYS) due to vaping by 2100, from 143 000 to 65 million. Most scenarios result in millions of individuals quitting smoking due to vaping. On average, vaping-induced quitters gain an extra 1.2-2.0 years of life compared to smokers who quit without vaping. The impact of vaping is greatest when it most helps smokers who otherwise have the greatest difficulty quitting smoking. While the numbers of LYS are generally large across all scenarios, they often represent a small fraction of the toll of smoking.

CONCLUSIONS

Vaping is highly likely to reduce smoking-produced mortality. Still, vaping is not "the" answer to the public health crisis created by smoking. Rather, it may well be a tool to add to the armamentarium of effective tobacco control measures.

IMPLICATIONS

E-cigarettes hold the potential to reduce cigarette smoking's enormous toll. By itself, however, tobacco harm reduction, as embodied in vaping, is no magic bullet. Going forward, tobacco control will require vigilant application of the evidence-based measures that have brought us so much success in combatting smoking. It will require, as well, the search for and adoption of novel means of attacking the remaining problem. Harm reduction can, and many would say should, be a part of the complex formula that will eventually bring about the demise of smoking.