1. Ophthalmology, Otolaryngology and Emergency Medicine; Director, Division of Neuro-Visual and Vestibular Disorders; and Director, Armstrong Institute Center for Diagnostic Excellence , The Johns Hopkins University School of Medicine , Johns Hopkins Hospital, CRB-II, 2M-03, 1550 Orleans Street , Baltimore, MD 21231 , USA
2. The Johns Hopkins University School of Medicine , Baltimore, MD , USA
3. The Leapfrog Group , Washington, DC , USA
4. Society to Improve Diagnosis in Medicine , NY , USA ; and RTI International, Research Triangle Park, NC, USA