The effect of smoking on individual well-being: a propensity score matching analysis based on nationwide surveys in Japan

Background: It is widely known that smokers tend to feel less satisfied than non-smokers with their jobs and life more generally. However, it is not easy to establish a causal relationship between smoking and individual well-being, because of shared associations with socioeconomic or demographic factors. This issue was largely avoided in the present study, which used propensity score matching methods to investigate whether smoking affects the extent to which individuals are satisfied with their job and other aspects of their life. Methods: Using a large-scale Japanese dataset, we first estimated propensity scores for smoking as a function of numerous socioeconomic and demographic factors. We then matched smokers to non-smokers on the basis of these. We subsequently estimated the average treatment effect, considering smoking as a treatment and smokers as the treated group. We used different matching methods to ascertain the robustness of any effects. Results: We found that smoking made both males and females unhappy, and that it reduced both the extent to which they were satisfied with multiple aspects of their lives (including their job, non-working activities, household's financial conditions, family life, friendships, residential area, health and physical conditions) and their level of self-rated health. Some of these effects differed between males and females. Conclusions: Our propensity score matching analyses identified smoking as having direct adverse effects on individual well-being.