Smoking reduction in the Lung Health Study.

We examined the ability of smokers who failed to quit smoking in the Lung Health Study to reduce the number of cigarettes per day and maintain this reduction and whether reduction predicted increased or decreased future cessation. In the Lung Health Study, among smokers with early lung disease who wished to stop smoking, 3923 were randomized to a special intervention of counseling and nicotine gum for smoking cessation and to bronchodilator therapy or placebo. Among the 1722 who were still smoking at the first year follow-up, 27% smoked the same, 43% smoked 1%-49% fewer, and 30% smoked at least 50% fewer cigarettes per day. Reduction in cigarettes per day was accompanied by reduction in expired-air carbon monoxide. About half of the less-than-50% reducers and one-fifth of the at-least-50% reducers maintained or exceeded this reduction over the next 4 years. Reduction was associated with nicotine gum use. Greater reduction at year 1 predicted more quit attempts in year 2 but not more point prevalence abstinence at year 2 nor more quits or abstinence between years 2 and 5. We conclude that reduction can be maintained but such reduction neither predicts an increased nor decreased probability of future cessation.