Smoking Cessation and Short- and Longer-Term Mortality

Quitting smoking at any age, preferably early, is remarkably and quickly effective

Worldwide, there are more than 1 billion smokers,¹ and smokers who start early in life and do not quit can expect to lose at least 12 to 13 years of life on average (combining at least 24–26 years lost for those killed by their smoking and zero years lost for those who are not).^1-3

Many adult smokers think, wrongly, that they gain little from cessation. However, important evidence from prospective studies in high-income countries where cessation has become common demonstrates that quitting, particularly before age 40 years, is remarkably effective.⁴

Our analysis of four large prospective studies covering 1.5 million adults and 120,000 deaths over 15 years documents the substantial and rapid benefits of smoking cessation.³ We observed that quitting smoking for a short duration (<3 years) was associated with a significantly reduced excess risk of mortality, with reductions of 95% in women and 90% in men under the age of 40 years. The reductions in risk were notable among women and men aged 40 to 49 years (81% and 61%, respectively) and 50 to 59 years (63% and 54%, respectively). Notably, quitting at any age was associated with prolonged survival, with quitting before the age of 40 years being particularly effective. Across all age groups, compared with individuals who continued smoking, those who quit for less than 3 years averted 5 years of life lost. Cessation for 10 years or more was associated with averting approximately 10 years of life lost, resulting in survival rates approaching those of never smokers. Life-year gains from cessation were largest for vascular diseases, with approximately 7 years gained among individuals who quit less than 3 years ago (see figure).

In conclusion, the evidence underscores the effectiveness of smoking cessation and its relatively quick benefits. It behooves healthcare professionals and public policymakers to more vigorously emphasize the advantages of quitting.¹

Figure: Years of life between ages 40–79 years by duration of quitting smoking compared with life gained by never smoking

Conflict of interest statement

The authors disclosed no conflict of interest.

Acknowledgements

External funding is from the Canadian Institutes of Health Research (FDN-154277). PJ is supported by the University of Toronto Chair program and a Canada Research Chair in Global Health.

Editorial Notes

The author calculations are from Cho et al.³

References

1. Jha P, Peto R. Global Effects of Smoking, of Quitting, and of Taxing Tobacco. N Engl J Med. 2014;370(1):60-68. https://www.nejm.org/doi/10.1056/NEJMra1308383
2. Jha P. The Hazards of Smoking and the Benefits of Cessation: A Critical Summation of the Epidemiological Evidence in High-Income Countries. Elife. 2020;9:e49979. https://elifesciences.org/articles/49979
3. Cho ER, Brill IK, Gram IT, et al. Smoking Cessation and Short- and Longer-Term Mortality. NEJM Evid. 2024;3(3):EVIDoa2300272. https://evidence.nejm.org/doi/10.1056/EVIDoa2300272
4. Jha P, Ramasundarahettige C, Landsman V, et al. 21st-Century Hazards of Smoking and Benefits of Cessation in the United States. N Engl J Med. 2013;368(4):341-350. https://www.nejm.org/doi/10.1056/NEJMsa1211128