Estimated public health gains from German smokers switching to risk-reduced alternatives: Results from population health impact modelling

Background Smoking is associated with cancer and cardiorespiratory disease mortality. Reducing smoking prevalence reduces deaths and life-years lost. Here, we estimate the impact of introducing heat-not-burn products and e-cigarettes in Germany from 1995 to 2015 on mortality from lung cancer, chronic obstructive pulmonary disease, ischaemic heart disease, and stroke in men and women aged 30–79 years. Methods We used the previously described population health impact model. Modelling starts with individuals of a given sex and age range with a defined cigarette smoking distribution. They are then followed under a “Null Scenario”, where reduced-risk products are never introduced, and one of seven “Alternative Scenarios”, where they are. Transition probabilities allow tobacco product use to change annually, and the individual product histories then allow estimation of risks, relative to never users, for each year and Scenario, which are then used to estimate reductions in deaths and life-years lost for each Alternative Scenario. Results In the Null Scenario, we estimated 852,357 deaths from cigarette smoking, with 8.61 million life-years lost. Had everyone quit in 1995, with no further use of the three products, these numbers would reduce by 216,650 and 2.88 million. The reductions would be 159,278 and 2.06 million with an immediate complete switch from cigarettes to heat-not-burn products, and 179,470 and 2.34 million with an immediate switch to 50% heat-not-burn products and 50% e-cigarettes. In four Scenarios with a more gradual switch, estimated decreases were 39,818–81,293 deaths and 0.50–1.05 million life-years, representing 17.5%-37.5% of the effect of cessation. These estimates assume switching to heat-not-burn products and e-cigarettes involves risk decreases of 80% and 95% of those from quitting. The decreases would have increased, had more diseases and a wider age range been considered, and also with a longer follow-up period, the decreases increasing markedly with time. Conclusions Various limitations are discussed, none affecting our conclusion that introducing these new products into Germany in 1995 could have substantially reduced mortality. Our results imply deaths from cigarette smoking could be substantially reduced, both by cessation and switching to reduced-risk products. Risk-proportionate public health campaigns and regulation might increase such switching.