1. Department of Otorhinolaryngology, Hospital Sierrallana, Cantabria, Spain;
2. Escuela de Fonoaudiología, Universidad Austral de Chile, Sede Puerto Montt, Chile;
3. Department of Otorhinolaryngology, Clinical Universidad de Navarra, Pamplona, Spain;
4. Department of Otorhinolaryngology, Complejo Hospitalario de Navarra, Pamplona, Spain;
5. Division of Health Care Quality, Hospital Universitario Marqués de Valdecilla, Idival, Spain