In 1983, the American Thoracic Society issued a position statement discouraging population screening for COPD . There were two main objections. First, it was felt that a positive ‘one-to-one’ correlation between decreased lung function in smokers and future development of COPD had not been adequately shown. A perfect correlation is rare in preventive medicine, but it can be argued that the association between decreased lung function and smoking that was established in the Lung Health Study is as sound as that between coronary artery disease and hypertension. The second objection was that the screening test must be able to detect disease at a point where effective intervention can affect the outcome. Again, the resounding success of smoking intervention in mild COPD in the Lung Health Study should adequately address any such concerns.