Baseline Characteristics for LEUVEN participants stratified for the clinical impact of airflow obstruction.

Abbreviations are the same as in Table 1. Percentages are column percentages. The 366 asymptomatic smokers are population-based participants of the Dutch-Belgian lung cancer screening trial (NELSON). None of them were previously diagnosed with COPD. However, 148 subjects (40.4%) were found to have an obstructive lung function (based on FEV1/FVC<0.70) at inclusion. Eleven subjects (2%), that were followed-up at the outpatient clinic because of symptoms compatible with COPD, did not fulfill the criterion of COPD (FEV1/FVC>0.70). Five patients with end-stage COPD were not actively listed for lung transplantation because of their current smoking status at inclusion.