1. Department of Obstetrics and Gynecology, The College of Medicine, The Ohio State University, Columbus, Ohio, USA.
2. Department of Sociology, University of Cincinnati, Cincinnati, Ohio, USA.
3. Behavioral Science Department, Blue Ash College, University of Cincinnati, Cincinnati, Ohio, USA.
4. Division of Epidemiology, College of Public Health, The Ohio State University, Columbus, Ohio, USA.
5. Department of Internal Medicine, College of Medicine, The Ohio State University, Columbus, Ohio, USA.