An analysis of available medical literature suggests smoking was linked to increased mortality in older patients and that smoking cessation was associated with reduced mortality at an older age, according to a report published in the June 11 issue of Archives of Internal Medicine, a JAMA Network publication.

Smoking is a known risk factor for many chronic diseases, including cardiovascular disease and cancer, however, the epidemiological evidence mostly relies on studies conducted among middle-aged adults, according to the study background.

"We provide a thorough review and meta-analysis of studies assessing the impact of smoking on all-cause mortality in people 60 years and older, paying particular attention to the strength of the association by age, the impact of smoking cessation at older age, and factors that might specifically affect results of epidemiological studies on the impact of smoking in an older population," Carolin Gellert and her colleagues from the German Cancer Research Center (DKFZ), Heidelberg, Germany, note in the study.

The authors identified 17 studies from seven countries (the U.S., China, Australia, Japan, England, Spain and France) that were published between 1987 and 2011. The follow-up time of the studies ranged from 3 to 50 years and the size of the study populations ranged from 863 to 877,243 participants.

In summarizing the results from the 17 studies, the authors note an 83 percent increased relative mortality for current smokers and a 34 percent increased relative mortality for former smokers compared with never smokers.

"In this review and meta-analysis on the association of smoking and all-cause mortality at older age, current and former smokers showed an approximately 2-fold and 1.3-fold risk for mortality, respectively," the authors note. "This review and meta-analysis demonstrates that the relative risk for death notably decreases with time since smoking cessation even at older age."

This analysis was conducted in the context of the CHANCES project funded in the FP7 Framework Programme of DG-RESEARCH in the European Commission. The project is coordinated by the Hellenic Health Foundation, Athens, Greece. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Invited Commentary: Risk of Tobacco Deaths

In a commentary, Tai Hing Lam, M.D., of the University of Hong Kong, writes: "Most smokers grossly underestimate their own risks. Many older smokers misbelieve that they are too old to quit or too old to benefit from quitting."

"Because of reverse causality and from seeing deaths of old friends who had quit recently, some misbelieve that quitting could be harmful. A simple, direct, strong and evidence-based warning is needed," Lam continues.

"If you have helped two smokers quit, you have saved (at least) one life," the author concludes.