The global burden of tobaccoUsing data from 3,625 nationally representative surveys, the three new studies published in The Lancet and The Lancet Public Health by the Global Burden of Disease collaboration provide global estimates on smoking prevalence in 204 countries in men and women aged 15 and over, including age of initiation, associated diseases, and risks among current and former smokers, as well as the first analysis of global trends in chewing tobacco use.