[1] Sichuan Univ, West China Hosp, Dept Otorhinolaryngol Head & Neck Surg, Chengdu, Peoples R China
[2] Sichuan Univ, West China Sch Publ Hlth, Dept Epidemiol & Hlth Stat, Chengdu, Peoples R China
[3] Sichuan Univ, West China Hosp 4, Chengdu, Peoples R China
[4] Dazhou Cent Hosp, Dept Outpatient Nursing, Dazhou, Peoples R China
[5] Santai Peoples Hosp, Dept Otorhinolaryngol Head & Neck Surg, Mianyang, Peoples R China