[1] Univ Toronto, Dept Speech Language Pathol, Fac Med, Toronto, ON M5G 1V7, Canada
[2] Univ Toronto, Radiat Med Program, Dept Radiat Oncol, Princess Margaret Canc Ctr,Univ Hlth Network, Toronto, ON M5G 2M9, Canada
[3] Toronto Western Hosp, Univ Hlth Network, Div Gastroenterol, Toronto, ON M5T 2S8, Canada
[4] Univ Toronto, Dept Otolaryngol Head & Neck Surg, Toronto, ON M5G 1V7, Canada
[5] Univ Hlth Network, Toronto Western Res Inst, Hlth Care & Outcomes Res, Toronto, ON, Canada