Smoking Cessation, or How to Avert Half a Billion Premature Deaths - Now.

An estimated 1.1 billion people currently smoke cigarettes, and 50 to 70% likely will die from tobacco-related causes. This translates to 550 to 770 million expected tobacco deaths among those who currently smoke. Many additional deaths will accrue in successive generations if the status quo continues. Of interest is the reversibility of the excess mortality risk of smoking. The meta-analysis by Cho et al. of four large national cohorts of nearly 1.5 million adults followed on average 14.8 years yielded 23.0 million person-years of observational data with over 120,000 deaths identified through linked death registries.