1. Department of Medicine, Veterans Affairs Medical Center, Minneapolis, Minnesota;
2. Division of Epidemiology, School of Public Health, and
3. Department of Epidemiology and Biostatistics, University of California, San Francisco, California;
4. Department of Medicine, University of California, Los Angeles, California; and
5. Department of Medicine, Veterans Affairs Medical Center, San Francisco, California.
6. College of Pharmacy, University of Minnesota, Minneapolis, Minnesota;