The Effects of a Smoking Cessation Intervention on 14.5-Year Mortality

Abstract

Randomized clinical trials have not yet demonstrated the mortality benefit of smoking cessation. To assess the long-term effect on mortality of a randomly applied smoking cessation program. The Lung Health Study was a randomized clinical trial of smoking cessation. Special intervention participants received the smoking intervention program and were compared with usual care participants. Vital status was followed up to 14.5 years. 10 clinical centers in the United States and Canada. 5887 middle-aged volunteers with asymptomatic airway obstruction. All-cause mortality and mortality due to cardiovascular disease, lung cancer, and other respiratory disease. The intervention was a 10-week smoking cessation program that included a strong physician message and 12 group sessions using behavior modification and nicotine gum, plus either ipratropium or a placebo inhaler. At 5 years, 21.7% of special intervention participants had stopped smoking since study entry compared with 5.4% of usual care participants. After up to 14.5 years of follow-up, 731 patients died: 33% of lung cancer, 22% of cardiovascular disease, 7.8% of respiratory disease other than cancer, and 2.3% of unknown causes. All-cause mortality was significantly lower in the special intervention group than in the usual care group (8.83 per 1000 person-years vs. 10.38 per 1000 person-years; P = 0.03). The hazard ratio for mortality in the usual care group compared with the special intervention group was 1.18 (95% CI, 1.02 to 1.37). Differences in death rates for both lung cancer and cardiovascular disease were greater when death rates were analyzed by smoking habit. Results apply only to individuals with airway obstruction. Smoking cessation intervention programs can have a substantial effect on subsequent mortality, even when successful in a minority of participants. *For a list of members of the Lung Health Study Research Group, see the Appendix.