Figure 1From: Gene susceptibility identification in a longitudinal study confirms new loci in the development of chronic obstructive pulmonary disease and influences lung function declineThe process of our study in the prospective follow-up stage. In the beginning (in 1992), COPD and controls who had same risk for developing COPD were identified after the lung function performed. In the 18-year follow-up, some controls developed into COPD.Back to article page