[1] Univ Michigan Hlth Syst, Div Laryngol, Ann Arbor, MI USA
[2] Univ Michigan Hlth Syst, Div Rhinol, Ann Arbor, MI USA
[3] Univ Michigan Hlth Syst, Div Gen Otolaryngol, Ann Arbor, MI USA
[4] Univ Michigan Hlth Syst, Div Pediat Otolaryngol, Dept Otolaryngol Head & Neck Surg, Ann Arbor, MI USA
[5] Oregon Hlth & Sci Univ, Dept Otolaryngol Head & Neck Surg, Portland, OR 97201 USA
[6] Univ Michigan Hlth Syst, Div Child Hlth Evaluat & Res Unit, Ann Arbor, MI USA
[7] Univ Michigan Hlth Syst, Dept Pediat & Communicable Dis, Ann Arbor, MI USA
[8] Univ Michigan Hlth Syst, Dept Internal Med, Ann Arbor, MI USA
[9] Univ Michigan, Gerald R Ford Sch Publ Policy, Ann Arbor, MI 48109 USA