1. Department of Social and Preventive Medicine, School of Public Health and Health Professions, State University of New York, Buffalo, New York, USA
2. Center for Perinatal Studies, Swedish Medical Center, Seattle, Washington, USA
3. Department of Epidemiology
4. Department of Biostatistics and
5. Department of Environmental and Occupational Health Sciences, School of Public Health, Seattle, Washington, USA
6. Harborview Injury Prevention and Research Center, Harborview Medical Center, Seattle, Washington, USA