1. Epidemiology Branch, Division of Epidemiology, Statistics and Prevention Research, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland,
2. W.H.O. Collaborating Center in Perinatal Care and Health Services Research in Maternal and Child Health, Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia,
3. Missouri Department of Health, Bureau of Health Data Analysis, Jefferson City, Missouri,
4. Department of Human Genetics, University of Utah, Salt Lake City, Utah,
5. Department of Epidemiology, University of Washington, Seattle, Washington, USA,
6. ICRF Cancer Epidemiology Unit, University of Oxford, Oxford, UK,
7. TVW Telethon Institute for Child Health Research, West Perth, Western Australia,
8. Central Bureau of Statistics, Health Division, Jerusalem, Israel,
9. University of Bergen, Section for Medical Informatics and Statistics, Bergen, Norway