1. Department of Emergency Medicine, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina
2. Department of Biostatistics, University of North Carolina-Chapel Hill, North Carolina
3. Department of Obstetrics and Gynecology, Duke University, Duke, North Carolina
4. Children’s Specialists of San Diego, San Diego, California
5. Department of Psychology, San Diego State University, San Diego, California
6. Institute for Minority Health Research, University of Illinois at Chicago, Chicago, Illinois
7. Division of General Medicine and Clinical Epidemiology, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina