The Journal of the American Medical Association has published the results of an analysis of data from the Nurses' Health Study that aimed to assess the relationship between cigarette smoking and smoking cessation on mortality.
The Nurses' Health Study is a prospective observational study of 104,519 American female nurses. The data were analysed for mortality from all causes and also categorised into vascular and respiratory diseases, lung cancer, other cancers and other causes. Comparisons were made between never smokers, current smokers and past smokers.
Compared to never smokers:
- Smokers were at 2.81 times higher risk of all-cause mortality (95% CI 2.68-2.95)
- Smokers were at 7.25 times higher risk of smoking-related cancers (95% CI 6.43-8.18)
- Smokers were are 1.58 times higher risk of other cancers (95% CI 1.45-1.73)
The study also found that risk was higher in people who started smoking at an earlier age and that risk declined to baseline over a period of 20 years for lung diseases with a more rapid decline for vascular mortality.
Action: These data contribute to what is already known about the harms of smoking and the benefits of smoking cessation. Clinicians may find the numerical risk data useful when encouraging abstinence from smoking.