In a previous study, 133 COPD patients were followed-up during the period of one-year. Analyses of the association between baseline characteristic and the occurence of disease exacerbation was performed. In this study, the patients included in the previous research will be contacted and invited to participate in a complete evaluation after a three-year period. The association of the changes in dyspnea perception, spirometry variables, body composition, quality of life and exercise tolerance measures with disease prognostic will be studied.