1. Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California;
2. Department of Research and Evaluation, Kaiser Permanente Southern California Medical Group, Pasadena, California;
3. Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, California;
4. Harbor–University of California, Los Angeles Medical Center, Torrance, California;
5. Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California.