The pediatric practices or individual practitioners who participated in this study are listed here by American Academy of Pediatrics chapter: Alaska: Anchorage Neighborhood Health Center, Anchorage Pediatric Group (Anchorage); Arizona: Mesa Pediatrics Professional Association (Mesa); California-1: Palo Alto Medical Clinic; California-4: Edinger Medical Group Inc (Fountain Valley); Colorado: Cherry Creek Pediatrics (Denver), Family Health Center (Denver); Connecticut: Arthur T. Blumer, MD (Southington); Florida: Atlantic Coast Pediatrics (Merritt Island); Georgia: The Pediatric Center (Stone Mountain); Hawaii: Melinda Ashton, MD (Honolulu); Iowa: David Kelly, MD (Marshalltown); Illinois: Southwest Pediatrics (Palos Park), Children's Memorial Hospital (Chicago), Kamala Ghaey, MD (Chicago); Indiana: Georgetown Medical Care (Indianapolis), Jeffersonville Pediatrics (Jeffersonville), Marshall County Pediatrics (Plymouth); Kansas: Ashley Clinic (Chanute), Bethel Pediatrics (Newton); Louisiana: Children's Clinic of Southwest Louisiana (Lake Charles); Massachusetts: Pediatric Associates of Norwood, Burlington Pediatric Associates, Framingham Pediatrics PC; Maryland: Children's Medical Group (Cumberland), Steven Caplan, MD (Baltimore), Coleman, Coleman, & Sachs (Rockville), Clinical Associates Pediatrics (Towson), Andorsky, Finkelstein, and Cardin (Owings Mills), Christopher Forrest, MD (Baltimore); Michigan: IHA Livingston Pediatrics (Howell), Lee & Kim Associates (Warren), Anuradha Sundararajan, MD (St Ignace), Pediatric Associates of Farmington PC, Children's Hospital of Michigan (Detroit); Missouri: Children's Clinic (Springfield); North Carolina: Hendersonville Pediatrics (Fletcher); ND, Altru Clinic (Grand Forks), MeritCare Medical Group-Pediatrics (Fargo); New Hampshire: Pediatric & Adolescent Medicine (Exeter), Laconia Clinic, Lahey-Hitchcock Clinic (Concord), Exeter Pediatric Associates; New Jersey: Delaware Valley Pediatric Association PA (Lawrenceville), Kids Care Pediatrics (Egg Harbor Township), Lourdes Pediatrics Association (Camden), University Pediatric Associates (East Brunswick); New Mexico: Albuquerque Pediatric Associates Ltd (Albuquerque); New York-1: Elmwood Pediatric Group (Rochester), Panorama Pediatric Group (Rochester), Brighton Hill Pediatrics (Syracuse), Edward Lewis, MD (Rochester), Park Medical Group (Rochester); Ohio: Pediatrics (Portsmouth), Oxford Pediatrics & Adolescents, Children's Hospital Physicians (Twinsburg), South Dayton Pediatrics Inc (Dayton), North Central Ohio Family Care (Galion); Oklahoma: Pediatric & Adolescent Care (Tulsa); Rhode Island: Marvin Wasser, MD (Cranston); South Carolina: Carolina Primary Care (Columbia); Texas: Winnsboro Pediatrics, The Pediatric Clinic (Greenville); Utah: Gordon Glade, MD (American Fork), Mountain View Pediatrics (Sandy), Salt Lake Clinic (Sandy); Virginia: Stafford Pediatrics PC, Fishing Bay Family Practice (Deltaville), Drs Casey, Goldman, Lischwe, Garrett, & Kim (Arlington); Vermont: Rebecca Collman, MD (Colchester), Judy Orton, MD (Bennington), Mousetrap Pediatrics (Milton), University Pediatrics (Burlington), Practitioners of Pediatric Medicine (South Burlington), University Pediatrics (Williston); Washington: Rockwood Clinic (Spokane), Redmond Pediatrics; Wisconsin: LaSalle Clinic (Neenah), Beloit Clinic SC, Gundersen Clinic (La Crosse), Gundersen Clinic (Whitehall), Medical Associates North (Ashland), Waukesha Pediatric Associates, Dean Clinic (Madison); West Virginia: Grant Memorial Pediatrics (Petersburg); Wyoming: Jackson Pediatrics, Bighorn Pediatric Associates (Gillette).