Modelling the health benefits of smoking cessation in Japan

Background: In Japan, tobacco smoking is one of the main avoidable causes of disease and death. Although the benefits of smoking cessation for reducing disease risk and increasing longevity have been extensively documented, a relatively low proportion of Japanese smokers currently express a willingness to quit. This study attempted to quantify future reduction in the burden of smoking-attributable disease that could result from increases in smoking cessation. Methods: A simulation model was developed to project changes in mortality in Japan associated with increased quit attempts and use of nicotine replacement therapy (NRT) among smokers, incorporating data on smoking prevalence, cause-specific mortality rates, quitting behaviour and NRT use and effectiveness. Results: Approximately 46 000 lung cancer deaths and 56 000 cardiovascular disease deaths could be avoided over 20 years if the proportion of smokers making a quit attempt per year gradually increased to current US levels over 20 years. If each of these quit attempts were aided by NRT, the estimates of avoidable deaths would increase to 64 000 for lung cancer and 78 000 for cardiovascular disease. In this model, negligible deaths were avoided due to decreased smoking initiation over the 20-year simulation. Conclusion: Smoking cessation can have measurable short-term impacts on the smoking-related mortality burden in Japan. However, to achieve these gains, tobacco control policies should focus both on increasing smokers' willingness to quit and providing the support and therapies to increase the likelihood that smoking cessation attempts will succeed.