1. California Pacific Medical Center Research Institute;
2. Department of Epidemiology and Biostatistics, University of California, San Francisco;
3. Center for Chronic Disease Outcomes Research, Minneapolis VA Health Care System;
4. Division of Epidemiology and Community Health and
5. Department of Medicine, University of Minnesota, Minneapolis;
6. Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh;
7. Oregon Health and Science University, Portland.