Much of the increased risk of death from smoking reduced within several years after quitting

“Tobacco use remains the leading preventable cause of death in the United States. Globally, approximately 5 million premature deaths were attributable to smoking in 2000. The World Health Organization projects by 2030 that tobacco-attributable deaths will annually account for 3 million deaths in industrialized countries and 7 million in developing countries,” the authors write. They add that the rate of mortality risk reduction after quitting compared with continuing to smoke is uncertain.

Stacey A. Kenfield, Sc.D., of the Harvard School of Public Health, Boston, and colleagues assessed the relationship between cigarette smoking and smoking cessation on total and cause-specific mortality in women by analyzing data from the Nurses’ Health Study, an observational study of 104,519 female participants, with follow-up from 1980 to 2004. A total of 12,483 deaths occurred in this group, 4,485 (35.9 percent) among never smokers, 3,602 (28.9 percent) among current smokers, and 4,396 (35.2 percent) among past smokers.

The researchers found a significant 13 percent reduction in the risk of all-cause mortality within the first 5 years of quitting smoking compared with continuing to smoke, and the excess risk decreased to the level of a never smoker 20 years after quitting, with some causes taking more or less time. “Significant trends were observed with increasing years since quitting for all major cause-specific outcomes. A more rapid decline in risk after quitting smoking compared with continuing to smoke was observed in the first 5 years for vascular diseases compared with other causes.”

“Much of the reduction in the excess risk for these causes of death were realized within the first 5 years for coronary heart disease and cerebrovascular disease. Sixty-one percent of the full potential benefit of quitting in regard to coronary heart disease mortality and 42 percent of the full potential benefit of quitting in regard to cerebrovascular mortality was realized within the first 5 years of quitting smoking, when comparing hazard ratios for recent quitters of less than 5 years with long-term quitters of 20 years or greater. For death due to respiratory disease, an 18 percent reduction in risk of death was observed 5 to 10 years after quitting smoking, with the risk reaching that of a never smoker’s risk after 20 years.”

For lung cancer mortality, a significant 21 percent reduction in risk was observed within the first 5 years compared with continuing smokers, but the excess risk did not disappear for 30 years. Past smokers with 20 to less than 30 years of cessation had an 87 percent reduction in risk of lung cancer mortality compared with current smokers. When including the other smoking-related cancers, the excess risk approached a never smoker’s risk more than 20 years after quitting smoking.

Significant trends were observed for earlier age at initiation of smoking for total mortality, respiratory disease mortality, and all smoking-related cancer mortality. The data also suggested that smoking is associated with an increased risk of colorectal cancer mortality but not ovarian cancer mortality. The researchers also found that approximately 64 percent of deaths among current smokers and 28 percent of deaths among former smokers were attributable to cigarette smoking.

“Early age at initiation is associated with an increased mortality risk so implementing and maintaining school tobacco prevention programs, in addition to enforcing youth access laws, are key preventive strategies. Effectively communicating risks to smokers and helping them quit successfully should be an integral part of public health programs,” the authors conclude.

Source: JAMA and Archives Journals

Drug abuse accounts for a third of the deaths behind Scotland's higher mortality rate
Drug abuse accounts for a third of the deaths behind Scotland's higher mortality rate, according to a study published on bmj.com today.
Does too much sun cause melanoma?
We are continuously bombarded with messages about the dangers of too much sun and the increased risk of melanoma (the less common and deadliest form of skin cancer), but are these dangers real, or is staying out of the sun causing us more harm than good? Two experts debate the issue on BMJ.com today.
Fewer nonsmokers breathe cigarette fumes, CDC says
(AP) -- Nearly half of nonsmoking Americans are still breathing in cigarette fumes, but the percentage has declined dramatically since the early 1990s, according to a government study released Thursday.
Pregnancy associated with increased risk of heart attack
Although acute myocardial infarction (AMI) is rare in women of child-bearing age, pregnancy can increase a woman's risk of heart attack 3- to 4-fold, according to a study published in the July 15, 2008, issue of the Journal of the American College of Cardiology. Since women today may delay having children until later in life, and advances in reproductive medicine enable older women to conceive, the occurrence of AMI associated with pregnancy is expected to increase.
Low testosterone appears to increase long-term risk of death
Men may not live as long if they have low testosterone, regardless of their age, according to a new study. The results will be presented at The Endocrine Society's 90th Annual Meeting in San Francisco.
New study: Coffee drinkers have slightly lower death rates than people who do not drink coffee
A new study published today in Annals of Internal Medicine has good news for coffee drinkers: Regular coffee drinking (up to 6 cups per day) is not associated with increased deaths in either men or women. In fact, both caffeinated and decaffeinated coffee consumption is associated with a somewhat smaller rate of death from heart disease.
Smoking cuts life span by nearly five years: study
Smoking cigarettes has the same effect as cutting the life span by close to five years, according to a mortality risk chart released Tuesday in the US Journal of the National Cancer Institute.
CT lung cancer screening no cure-all for smokers
Screening for lung cancer with computed tomography (CT) may help reduce lung cancer deaths in current and former smokers, but it won't protect them from other causes of death associated with smoking, according to a new study published in the July issue of the journal Radiology.

Much of the increased risk of death from smoking reduced within several years after quitting

Related stories:

News discussion: