1. Duke Evidence Synthesis Group, Duke Clinical Research Institute, Durham, North Carolina2Department of Obstetrics and Gynecology, Duke University School of Medicine, Durham, North Carolina
2. Duke Evidence Synthesis Group, Duke Clinical Research Institute, Durham, North Carolina3Department of Community and Family Medicine, Duke University School of Medicine, Durham, North Carolina
3. Duke Evidence Synthesis Group, Duke Clinical Research Institute, Durham, North Carolina4Department of Medicine, Duke University School of Medicine, Durham, North Carolina5Center for Health Services Research in Primary Care, Durham Veterans Affairs Medical
4. Department of Radiology, Duke University School of Medicine, Durham, North Carolina
5. Department of Obstetrics and Gynecology, Duke University School of Medicine, Durham, North Carolina
6. Duke Evidence Synthesis Group, Duke Clinical Research Institute, Durham, North Carolina4Department of Medicine, Duke University School of Medicine, Durham, North Carolina
7. Duke Evidence Synthesis Group, Duke Clinical Research Institute, Durham, North Carolina