Smoking and Deaths between 40 and 70 Years of Age in Women and Men

21 March 2006 | Volume 144 Issue 6 | Pages 381-389

Background: The vast scientific literature on smoking and health contains few large studies with direct estimates of long-term mortality by smoking habits. Data have been lacking, particularly for women.

Objective: To study smoking and deaths and causes of death in women and men of middle age (40 to 70 years of age).

Design: Population-based cohort study.

Setting: Norway (the Norwegian Counties Study).

Participants: 24 505 women and 25 034 men who were born between 1925 and 1941.

Measurements: Initial information on smoking habits was collected between 1974 and 1978. Smoking status was also assessed about 5 years and 10 years after the first examination. Death during 1974 to 2000 was studied by using death certificate information.

Results: During follow-up, 2333 women and 4680 men died in middle age. Among women and men, 9% and 14% of never smokers, respectively, and 26% and 41% of continuing heavy smokers (20 cigarettes per day), respectively, died in middle age. Years of life lost among heavy smokers between 40 and 70 years of age were 1.4 years in women and 2.7 years in men, compared with never smokers. Rates of smoking-associated lung cancer were similar in women and men, while lower cardiovascular mortality rates in women explained most of the difference in smoking-associated all-cause mortality between men and women.

Limitations: Data on changes in smoking habits after the baseline examination were not available for all participants and for the last 15 years of follow-up. Mortality levels in middle age may not apply to non-Norwegian populations.

Conclusions: Continuing smoking strongly increased and smoking cessation decreased the risk for death between 40 and 70 years of age for both women and men. Despite similar rates for lung cancer death, women who smoked had lower mortality rates in middle age than men with similar smoking histories due to fewer cardiovascular deaths in women.

Editors' Notes Context The best way to estimate deaths from smoking is to observe people over many decades, as done in a 50-year study of male British physicians. No such study exists for women. Content A 25-year study of residents of rural Norway included 24 505 women. Of these women, 2333 women died at age 40 to 70 years (9.4% of never smokers and 18.7% of continuing smokers), mostly from cardiovascular disease and cancer. Continuing heavy smokers survived 1.4 fewer years than never smokers. Mortality rates in smokers and nonsmokers were lower in women than in men. Cautions Participants were white and lived in rural areas. Implications Active smoking has a large effect on women's longevity in middle age. —The Editors

 

Author and Article Information

From the University of Bergen, Bergen, Norway, and the Norwegian Institute of Public Health, Oslo, Norway.

Acknowledgments: The authors acknowledge the staff of the National Mass Radiography Service, who initiated the Norwegian Counties Studies in 1974 and continued data collection on cardiovascular risk factors in all Norwegian counties over the following decades. The authors also thank Hilde-Gunn Bruu for programming assistance.

Grant Support: None.

Potential Financial Conflicts of Interest: None disclosed.

Requests for Single Reprints: Stein Emil Vollset, MD, DrPH, Section for Epidemiology and Medical Statistics, Department of Public Health and Primary Health Care, University of Bergen, Kalfarveien 31, N-5018 Bergen, Norway.

Current Author Addresses: Dr. Vollset: Section for Epidemiology and Medical Statistics, Department of Public Health and Primary Health Care, University of Bergen, Kalfarveien 31, N-5018 Bergen, Norway.

Drs. Tverdal and Gjessing: Division of Epidemiology, Norwegian Institute of Public Health, P.O. Box 4404, Nydalen, N-0403 Oslo, Norway.

Author Contributions: Conception and design: S.E. Vollset, A. Tverdal.

Analysis and interpretation of the data: S.E. Vollset, A. Tverdal, H.K. Gjessing.

Drafting of the article: S.E. Vollset.

Critical revision of the article for important intellectual content: S.E. Vollset, A. Tverdal, H.K. Gjessing.

Final approval of the article: S.E. Vollset, A. Tverdal, H.K. Gjessing.

Provision of study materials or patients: A. Tverdal.

Statistical expertise: S.E. Vollset, A. Tverdal, H.K. Gjessing.

Administrative, technical, or logistic support: S.E. Vollset.

Collection and assembly of data: A. Tverdal.