1. From the Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York (S. Shea, L.T., L.Y.-C., A.R.T.)
2. Department of Epidemiology, Mailman School of Public Health, Columbia University, New York (S. Shea)
3. Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison (J.H.S.)
4. Department of Biostatistics, University of Washington, Seattle (N.W.J., R.L.M., S. Shrager)
5. Department of Medicine, University of Washington, Seattle (J.W.H.)