[1] Univ Minnesota, Dept Med, Box 736 UMHC, Minneapolis, MN 55455 USA
[2] Univ Minnesota, Div Epidemiol & Community Hlth, Minneapolis, MN 55454 USA
[3] Calif Pacific Med Ctr, Res Inst, San Francisco, CA USA
[4] Univ N Carolina, Dept Family Med, Chapel Hill, NC USA
[5] Pk Nicollet Clin, Minneapolis, MN USA
[6] HealthPartners Inst, Minneapolis, MN USA
[7] Univ Minnesota, Div Hlth Policy & Management, Minneapolis, MN USA
[8] VA Hlth Care Syst, Ctr Chron Dis Outcomes Res, Minneapolis, MN USA
[9] Oregon Hlth & Sci Univ, Bone & Mineral Unit, Portland, OR 97201 USA
[10] Univ Pittsburgh, Dept Epidemiol, Pittsburgh, PA 15261 USA
[11] Univ Calif Los Angeles, Dept Med, Los Angeles, CA 90024 USA