Smoking Reduction, Smoking Cessation, and Mortality: A 16-year Follow-up of 19,732 Men and Women from the Copenhagen Centre for Prospective Population Studies

Abstract

The authors investigated the association between changes in smoking habits and mortality by pooling data from three large cohort studies conducted in Copenhagen, Denmark. The study included a total of 19,732 persons who had been examined between 1967 and 1988, with reexaminations at 5- to 10-year intervals and a mean follow-up of 15.5 years. Date of death and cause of death were obtained by record linkage with nationwide registers. By means of Cox proportional hazards models, heavy smokers (>or=15 cigarettes/day) who reduced their daily tobacco intake by at least 50% without quitting between the first two examinations and participants who quit smoking were compared with persons who continued to smoke heavily. After exclusion of deaths occurring in the first 2 years of follow-up, the authors found the following adjusted hazard ratios for subjects who reduced their smoking: for cardiovascular diseases, hazard ratio (HR) = 1.01 (95% confidence interval (CI): 0.76, 1.35); for respiratory diseases, HR = 1.20 (95% CI: 0.70, 2.07); for tobacco-related cancers, HR = 0.91 (95% CI: 0.63, 1.31); and for all-cause mortality, HR = 1.02 (95% CI: 0.89, 1.17). In subjects who stopped smoking, most estimates were significantly lower than the heavy smokers'. These results suggest that smoking reduction is not associated with a decrease in mortality from tobacco-related diseases. The data confirm that smoking cessation reduces mortality risk.

HIV infection, aging and cardiovascular disease: epidemiology and prevention

“…[98][99][100][101][102][103] Similarly, recent findings from the D:A:D study demonstrated a decreasing risk in CVD with increasing years of having stopped smoking. 31 Nevertheless, preventing smoking in HIV-positive patients is challenging.…”

How should we define light or intermittent smoking? Does it matter?

“…Luoto et al (2000) reported that after 18 years of follow-up, occasional smokers had an increased RR (1.6) for total mortality and for CVD mortality (1.5) and that CVD risk was comparable for light and heavier smokers. Godtfredsen, Holst, Prescott, Vestbo, and Osler (2002) reported that smokers who reduced their consumption by 50% had no reduction in CVD, respiratory diseases, tobacco-related cancers, or all-cause mortality compared with continuing heavy smokers.…”

Tobacco Cessation in Primary Care: Maximizing Intervention Strategies

“…25 In a study of 19,732 patients, smoking reduction yielded no decrease in mortality from tobacco-related disease. 26 The only known way to reduce cancer risk in smokers is complete cessation, which results in a 35% lower risk of death due to tobacco-related illness and a 64% reduced risk of tobacco-related cancer. [27][28][29] The only benefit to the smoker in reducing the number of cigarettes smoked may be greater ease in quitting.…”