NHLBI study shows smoking cessation programs improve survival

New findings from the Lung Health Study (LHS) show that intensive smoking cessation programs can significantly improve long-term survival among smokers. Supported by the National Heart, Lung, and Blood Institute (NHLBI), LHS is a landmark study that differs from many other studies of cigarette smoking in that it was a randomized, controlled clinical trial — considered the gold standard in determining cause and effect; furthermore, the size and duration of LHS enabled it to more accurately measure the risks associated with smoking than other clinical trials. NHLBI is part of the National Institutes of Health.

LHS followed nearly 5,900 middle-aged smokers who had mild to moderately abnormal lung function but were otherwise healthy when they enrolled in the study. Participants were assigned to either a 10-week intensive smoking cessation program or to usual care (no intervention). The intervention program included behavior modification and use of nicotine gum, with a continuing five-year maintenance program to minimize relapse. After five years, approximately 22 percent of the participants in the smoking cessation program were sustained quitters, with nearly 90 percent of them continuing their success after 11 years. About 5 percent of those who did not receive the intervention were sustained quitters after five years. After an average of 14.5 years, the death rate among those in the smoking cessation program was about 15 percent lower compared to those who received usual care. The results are published in the February 15, 2005, issue of the Annals of Internal Medicine.

“This study shows the substantial impact smoking cessation programs can have on public health, even if small numbers of participants successfully quit,” said Gail Weinmann, MD, director of the NHLBI Airway Biology and Disease Program.

Researchers also analyzed mortality data according to smoking habit regardless of whether participants were in the intervention or usual care groups. At the end of the study they found that sustained quitters had nearly half the overall death rate of those who continued to smoke. In particular, death rates of sustained quitters compared to smokers were nearly one-third lower for coronary heart disease and for cardiovascular disease, and less than half for lung cancer.

In an accompanying editorial, Jonathan Samet, MD, MS, of the Johns Hopkins Bloomberg School of Public Health, notes that the LHS findings prove that “smoking is causally responsible for the increased risk for death in smokers.” He asserts, “No one can make a serious claim to the contrary in light of this randomized trial evidence.”

Smoking is the single most avoidable cause of disease, disability, and death in the United States. According to the Centers for Disease Control and Prevention, approximately 22.5 percent of adults (46 million) and 26 percent of high school seniors smoke. Smoking contributes to more than 440,000 deaths per year.