1. Veterans Affairs Palo Alto Health Care System, Palo Alto, CA;
2. Center for Primary Care and Outcomes Research/Center for Health Policy, Department of Medicine, Stanford University School of Medicine,
3. Department of Otolaryngology–Head and Neck Surgery,
4. Stanford University School of Medicine,
5. Department of Management Science and Engineering, and
6. Division of Hematology, Stanford University School of Medicine, Stanford University, Stanford, CA