1. Respiratory Service,
2. Research Unit, and
3. Hematology Service, University Hospital of Gran Canaria Dr. Negrín, Las Palmas de Gran Canaria, Spain;
4. Research Unit, La Candelaria University Hospital, Santa Cruz de Tenerife, Spain;
5. Hematology Service, La Candelaria University Hospital, Santa Cruz de Tenerife, Spain;
6. Mathemathics, Statistics and Operations Research Department, IMAULL Institute, La Laguna University, San Cristóbal de La Laguna, Spain;
7. Pulmonary and Critical Care Division, Brigham and Women’s Hospital, Harvard Medical School, Harvard University, Boston, Massachusetts; and
8. Pulmonary Department, Research Unit, La Candelaria University Hospital, La Laguna University, Carlos III Health Institute Biomedical Research Center, San Cristóbal de La Laguna, Spain