Smoking-related mortality may be higher than previously estimated

HealthDay News — Mortality among current smokers is two to three times as high as that among patients who never smoked, according to findings published in the New England Journal of Medicine.

The United States Surgeon General estimates that nearly 480,000 Americans die of smoking-related causes each year, but Brian Carter, MPH, of the American Cancer Society,  and colleagues suggest that figure may be closer to 540,000.

“Most of this excess mortality is believed to be explained by 21 common diseases that have been formally established as caused by cigarette smoking and are included in official estimates of smoking-attributable mortality in the United States,” noted the investigators.

“However, if smoking causes additional diseases, these official estimates may significantly underestimate the number of deaths attributable to smoking.”

To determine if excess mortality among smokers was due to associations with diseases that may not have been formally established as caused by smoking, the researchers culled data from five large databases that included 954,029 men and women aged 55 years and older.

During nearly 10 years of follow-up, 181,377 people died. The death rate among people who smoked was three times higher compared with those who had never smoked. Most of these deaths were the result of diseases known to be related to smoking, such as certain cancers, heart disease, stroke, and chronic pulmonary disease (COPD).

However, about 17% of the deaths in smokers were due to diseases that were not established by caused by smoking by the Surgeon General, and these deaths are not included in estimates of death from smoking, noted the researchers.

“These associations should be investigated further and, when appropriate, taken into account when the mortality burden of smoking is investigated,” concluded the investigators.

Smoking was associated with at least a doubling of risk of death from several causes, including kidney failure, intestinal diseases, hypertensive heart disease, infections, and respiratory diseases other than COPD.