1 Respiratory Department, Hospital Central de la Defensa, Faculty of Medicine, Universidad de Alcalá, Madrid, Spain.
2 Respiratory Department, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Faculty of Medicine, Universidad Complutense de Madrid, CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain.
3 Department of Internal Medicine, Hospital Central de la Defensa, Faculty of Medicine, Universidad de Alcalá, Madrid, Spain.