Respiratory Dept, Hospital Universitari Arnau de Vilanova and Santa Maria, IRBLleida, Lleida, Spain. Both authors contributed equally to this study. Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain. Respiratory Dept, Hospital Universitari Germans Trias i Pujol, Badalona, Spain. Medicine Dept, OSI Araba University Hospital, UPV, BioAraba Institute, Vitoria, Spain. Adelaide Institute for Sleep Health: A Flinders Centre of Research Excellence, Flinders University, Adelaide, Australia. Respiratory Dept, Hospital Universitario de Guadalajara, Guadalajara, Spain. Respiratory Dept, Hospital de Cruces, Bilbao, Spain. Respiratory Dept, Hospital Parc Taulí, Sabadell, Spain. Respiratory Dept, Hospital General Yagüe, Burgos, Spain. Unit of Bioestatistics and Epidemiology, IRBLleida, Lleida, Spain. Respiratory Dept, Hospital Universitari Arnau de Vilanova and Santa Maria, IRBLleida, Lleida, Spain sanchezdelatorre@gmail.com.