[1] St Michaels Hosp, Dept Otolaryngol Head & Neck Surg, Unity Hlth Toronto, Toronto, ON, Canada
[2] Univ Toronto, Dept Otolaryngol Head & Neck Surg, Toronto, ON, Canada
[3] St Michaels Hosp, Adult Cyst Fibrosis Ctr, Unity Hlth Toronto, Toronto, ON, Canada
[4] Univ Toronto, Fac Med, Toronto, ON, Canada
[5] Univ Toronto, Dept Med, Div Respirol, Toronto, ON, Canada