1. Department of Otolaryngology–Head and Neck SurgeryUniversity of Washington Seattle Washington
2. Center for Causal Inference, Center for Clinical Epidemiology and BiostatisticsUniversity of Pennsylvania Philadelphia Pennsylvania
3. Department of BiostatisticsSchool of Public Health, University of Washington Seattle Washington
4. Department of MedicineDivision of Oncology, University of Washington Seattle Washington
5. Department of Otolaryngology–Head and Neck SurgeryUniversity of Utah Salt Lake City Utah