A study published in the New England Journal of Medicine reports that smoking may be responsible for 60,000 to 120,000 more deaths in the US each year than previously thought, according to a Reuters news article. Previous estimates put the attributable smoking deaths annually at 480,000 Americans.
Until now, 21 common diseases have been associated with cigarette smoking, including diabetes, 12 cancers and six forms of cardiovascular disease. Researchers say fatalities related to an additional seven diseases should be investigated further and, when appropriate, taken into account when the mortality burden of smoking is investigated:
- Renal failure
- Intestinal ischemia
- Hypertensive heart disease
- Various respiratory diseases
- Breast cancer
- Prostate cancer
For the study, researchers pooled data from five contemporary US cohort studies including 421,378 men and 532,651 women 55 years of age or older. Participants were followed from 2000 through 2011, and relative risks and 95% confidence intervals were estimated with the use of Cox proportional-hazards models adjusted for age, race, educational level, daily alcohol consumption, and cohort.
During the follow-up period, there were 181,377 deaths, including 16,475 among current smokers. Overall, approximately 17% of the excess mortality among current smokers was due to associations with causes that are not currently established as attributable to smoking (listed above.
Importantly, among former smokers, the relative risk for each of these outcomes declined as the number of years since quitting increased.