1Center for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center, Boston
2Academic Unit of Bone Metabolism, University of Sheffield, Sheffield, UK
3California Pacific Medical Center, San Francisco, CA, USA
4Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA
5Merck and Co. Inc., Kenilworth, NJ, USA
6Amgen Inc., Thousand Oaks, CA, USA
7Lilly Research Centre, Eli Lilly & Co., Surrey, UK
8Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
9Department of Medicine, University of California, San Fransisco, San Francisco, CA, USA