1 Department of Health Services Research, Care and Public Health Research Institute (CAPHRI), Maastricht University, PO Box 616, 6200 MD, Maastricht, The Netherlands.
2 WHO Collaborating Centre for Public Health Aspects of Musculoskeletal Health and Aging, Liege, Belgium.
3 Department of Epidemiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
4 Division of Endocrinology, Diabetes and Metabolism, Ohio State University Wexner Medical Center, Columbus, OH, USA.
5 Department of Medicine, University of California at Davis, School of Medicine, Sacramento, CA, USA.
6 Division of Public Health, Epidemiology and Health Economics, University of Liege, Liege, Belgium.
7 Cedars-Sinai Medical Center, Los Angeles, CA, USA.
8 David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
9 Departments of Obstetrics and Gynecology and Medicine, MedStar Georgetown University Hospital, Washington, DC, USA.
10 Department of Health Services Research, Care and Public Health Research Institute (CAPHRI), Maastricht University, PO Box 616, 6200 MD, Maastricht, The Netherlands. [email protected].