Hospital Clínic de Barcelona, Thorax Clinic Institute, Respiratory Diagnostic Centre, Barcelona, Catalonia, Spain. August Pi i Sunyer Biomedical Research Institute (IDIBAPS), University of Barcelona, Barcelona, Catalonia, Spain. Center for Biomedical Network Research in Respiratory Diseases (CIBERES), Barcelona, Catalonia, Spain. Parc de Salut Mar, Pulmonary Medicine Department, Hospital del Mar Medical Research Institute (IMIM), Pompeu Fabra University, Barcelona, Catalonia, Spain. Epidemiology Department, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Catalonia, Spain. Center for Biomedical Network Research in Epidemiology and Public Health (CIBERESP), Barcelona, Catalonia, Spain. Blanquerna Health Sciences Faculty, Ramon Llull University, Barcelona, Catalonia, Spain. Respiratory Department, Cardiovascular Foundation from Colombia Floridablanca, Santander, Colombia.