Methods
The Lung Health Study
The Lung Health Study is an ongoing five-year, ten-center National Heart, Lung, and Blood Institute-sponsored randomized clinical trial testing the hypothesis that smoking cessation and the regular use of an inhaled bronchodilator, ipratropium bromide, will slow the decline in lung function in smokers with early COPD. Eligible participants included men and women between the ages of 35 and 60 years at randomization who were active cigarette smokers and had spirometric evidence of mild to moderate airflow obstruction, as indicated by a ratio of FEV, to forced vital capacity of 70 percent or less and an FEV^ of 55 to 90 percent of predicted. Prior to randomization, participants were excluded if they had serious health problems which might limit study participation or life expectancy, or if they were regularly using a bronchodilator or beta-adrenergic blocking agent.
The 5,887 enrolled participants were randomly assigned to one of three groups: usual care, special intervention with active drug, or special intervention with placebo. Both active drug (ipratropium bromide) and placebo are dispensed as a MDI. Neither the investigators nor the participants knew whether the drug or placebo was assigned.
The usual care group returned for annual spirometry and health status questionnaires only. The special intervention participants were offered a standardized, multicomponent, 12-session, small-group smoking cessation program which included nicotine replacement (nicotine polacrilex) under medical supervision and cognitive-behavioral strategies such as stimulus control, avoidance, role-playing, assertiveness training, relaxation techniques, and group support. Each special intervention participant was asked to return for visits to a health educator every 4-months, in addition to having an annual spirometry examination.