1 Medical Surgical Unit of Respiratory Diseases, Virgen del Rocio Hospital, Seville, Spain; Instituto de Biomedicina de Sevilla, Centro de Investigación Biomédica en Red de Enfermedades Respiratorias, Seville, Spain. Electronic address: luisoneumo@hotmail.com.
2 Medical Surgical Unit of Respiratory Diseases, Virgen del Rocio Hospital, Seville, Spain; Instituto de Biomedicina de Sevilla, Centro de Investigación Biomédica en Red de Enfermedades Respiratorias, Seville, Spain.
3 Respiratory Department, Ramón y Cajal Hospital, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.
4 Statistics, Methodology and Research Evaluation Unit, Andalusian Public Foundation for Health Research Management, Hospital Virgen del Rocío, Seville, Spain.
5 Department of Internal Medicine, Hospital Universitari Germans Trias i Pujol de Badalona, Barcelona, Universidad Católica de Murcia, Spain.