1. Hospital de la Santa Creu I Sant Pau, Barcelona, Spain
2. Hospital Virgen Rocío, Sevilla, Spain
3. Instituto de Biomedicina de Sevilla, Sevilla, Spain
4. Hospital Clínico San Carlos, Madrid, Spain
5. Hospital Universitario Cruces, Barakaldo-Biocruces Health Research Institute, Barakaldo, Spain
6. CIBER de Epidemiología y Salud Pública, Madrid, Spain
7. Spanish Clinical Research Network, Madrid, Spain
8. Hospital La Madalena, Castellón, Spain
9. Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Boston, Massachusetts; and
10. CibeRes, Madrid, Spain