[1] Hosp Sao Sebastiao, Dept Otorhinolaryngol, Sta Maria Da Feira, Portugal
[2] Univ Porto, CINTESIS, Ctr Res Hlth Technol & Informat Syst, P-4100 Oporto, Portugal
[3] Univ Porto, Fac Med, Dept Pediat, P-4100 Oporto, Portugal
[4] Univ Porto, Fac Med, Dept Pulmonol, P-4100 Oporto, Portugal