The authors began their analysis with a “Status Quo Scenario for smoking rates and health outcomes.” They then estimated cigarettes being replaced by use of e-cigarettes, and projected mortality and life years lost in each model.
The study estimated future cigarette use and mortality outcomes in both the status quo and e-cigarette substitution scenarios. In the e-cigarette scenarios, the authors hypothesized two outcomes of e-cigarette use. In the optimistic scenario, the authors assume “the prevalence of cigarette use will be reduced to a 5% residual prevalence of e-cigarette use … and to 10% in the pessimistic scenario.” The authors then calculated health outcomes, including total premature deaths and life years lost under the optimistic and pessimistic e-cigarette use models.
The authors found that in the optimistic e-cigarette use scenario, “replacement of cigarette by e-cigarette use over a 10-year period yields 6.6 million fewer premature deaths with 86.7 million fewer life years lost.” In the pessimistic scenario, “1.6 million premature deaths are averted with 20.8 million fewer life years lost.”
The authors note that contributing factors may impact the data, including taxation and prohibition of vapor products. Further, other policies may impact initiation. Nonetheless, the authors note that “replacing cigarette smoking with e-cigarette use would yield substantial life year gains, even under pessimistic assumptions regarding cessation, initiation and relative harm.”
The study provides further evidence of the reduced harm of e-cigarettes and vapor products. By reducing combustible cigarette use, adult smokers can achieve significant health outcomes, including higher mortality rates and fewer life years lost.
Introduction: US tobacco control policies to reduce cigarette use have been effective, but their impact has been relatively slow. This study considers a strategy of switching cigarette smokers to e-cigarette use (‘vaping’) in the USA to accelerate tobacco control progress.
Methods: A Status Quo Scenario, developed to project smoking rates and health outcomes in the absence of vaping, is compared with Substitution models, whereby cigarette use is largely replaced by vaping over a 10-year period. We test an Optimistic and a Pessimistic Scenario, differing in terms of the relative harms of e-cigarettes compared with cigarettes and the impact on overall initiation, cessation and switching. Projected mortality outcomes by age and sex under the Status Quo and E-Cigarette Substitution Scenarios are compared from 2016 to 2100 to determine public health impacts.
Findings: Compared with the Status Quo, replacement of cigarette by e-cigarette use over a 10-year period yields 6.6 million fewer premature deaths with 86.7 million fewer life years lost in the Optimistic Scenario. Under the Pessimistic Scenario, 1.6 million premature deaths are averted with 20.8 million fewer life years lost. The largest gains are among younger cohorts, with a 0.5 gain in average life expectancy projected for the age 15 years cohort in 2016.
Conclusions: The tobacco control community has been divided regarding the role of e-cigarettes in tobacco control. Our projections show that a strategy of replacing cigarette smoking with vaping would yield substantial life year gains, even under pessimistic assumptions regarding cessation, initiation and relative harm.
Science Media Centre, expert reaction to study of what would happen if all smokers switched to e-cigs, 2017Read Report