1. aDivision of Pediatric Hospital Medicine, Stanford University School of Medicine, Palo Alto, California
2. bDepartment of Pediatric Hospital Medicine, Kaiser Permanente Northern California, Oakland, California
3. cDivision of Pediatric Hospital Medicine, Palo Alto Medical Foundation, Palo Alto, California
4. dDepartments of Epidemiology and Biostatistics and Pediatrics, University of California, San Francisco, California
5. eDepartment of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina