1. Department of Epidemiology, Brown University School of Public Health, Box G-S121-2, Providence, Rhode Island 02903, United States
2. Department of Biostatistics, Brown University School of Public Health, Providence, Rhode Island 02903, United States
3. Centers for Disease Control and Prevention, Atlanta, Georgia 30329-4018, United States
4. Center for Primary Care and Prevention, Memorial Hospital of Rhode Island, Pawtucket, Rhode Island 02860-4499, United States
5. Department of Family Medicine, Brown University School of Medicine, Providence, Rhode Island 02912, United States
6. Department of Biostatics, Epidemiology & Informatics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, United States
7. Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
8. Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio 45229-3026, United States