The US Lung Health Study

The US Lung Health Study was a randomized clinical trial carried out in 10 clinical centres in the United States of America and Canada that enrolled 5887 male and female smokers age 35-60 years with early chronic obstructive pulmonary disease (COPD). Its purpose was to determine whether a programme incorporating smoking intervention and use of an inhaled bronchodilator (ipratropium bromide) can slow the rate of decline in the forced expiratory volume in one second (FEV₁) in middle aged smokers with early COPD. Participants were randomized with equal probability into three groups: (i) smoking intervention plus bronchodilator; (ii) smoking intervention plus placebo; or (iii) no intervention. The primary outcome was rate of change and cumulative change in FEV₁ over a 5 year period. The primary finding was that the use of the bronchodilator did not influence the long-term decline in FEV₁. However, the aggressive smoking intervention programme significantly reduced the age-related decline in FEV₁.